Magnetic Resonance in the Subsurface – 5th International ... - LIAG

Magnetic Resonance 

in the Subsurface 

5 th International Workshop 

on Magnetic Resonance 

September 25 – 27, 2012 

Hannover, Germany 

Program & Abstracts

General Information 

Meeting Venue 

The 5th international workshop on Magnetic Resonance in the subsurface will be held at the Leibniz 

Institute for Applied Geophysics in Hannover, Germany. The auditorium is located directly behind the 

entrance (indicated by the red arrow in the picture below) in building part A. 

Magnetic Resonance in the Subsurface – 5 th International Workshop on Magnetic Resonance 

Hannover, Germany, 25 – 27 September 2012 

2

Poster Presentation 

Posters are displayed during the complete conference. The poster area is side-by-side with the 

auditorium. At the poster area the coffee breaks are located too, so there will be room and time for 

discussions. 

Lunch 

Lunch is available at the GeoZentrum restaurant located in building part F. The restaurant operates 

without cash. You will need to get a Guest-Card at the entrance of the restaurant to pay for the lunch. 

Field Experiment 

A field experiment will take place on Wednesday between 16.00 and 17.30 at a test site close to the 

conference location. Using the measurement equipments for Surface-NMR available at GeoZentrum 

Hannover, the issues of measurements and data collection will be discussed, and it will particularly be 

shown how Surface-NMR can be measured in urban areas. 



3

Conference Evening 

The conference evening will take place at the “Schlossküche Herrenhausen” on Wednesday 26 th starting 

at 18.30. From the conference you can use the public transport of Hannover. Take the tram number 7 

(direction Wettbergen) until “Kröpke”, at “Kröpke” change for tram number 4 (direction Garbsen) until 

Herrenhäuser Gärten. From there, it is a short distance to walk. 



4

Scientific Committee 

Yaramanci, Ugur Leibniz Institute for Applied Geophysics 

(LIAG) 

Müller-Petke, Mike Leibniz Institute for Applied Geophysics 

(LIAG) 

Auken, Esben Aarhus University 

(AU) 

Costabel, Stephan Federal Institute of Geosciences and 

Resources (BGR) 

Girard, Jean-Francois Bureau de recherches géologiques et 

minières (BRGM) 

Knight, Rosemary Stanford University 

(SU) 

Lange, Gerhard Federal Institute of Geosciences and 

Resources (BGR) 

Legtchenko, Anatoly Institute de recherche pour le 

development (IRD) 

Plata, Juan Luis Instituto Geologico y minero de Espana 

(IGME) 

List of Participants 

(Registered as with 6 th September 2012) 

Name First Name Affiliation Email 



Aarhus, Denmark 


Orleans, France 

Stanford, USA 


Grenoble, France 

Madrid, Spain 

Aaron Davis CSIRO aaron.davis@csiro.au 

Abraham Jared USGS jdabraha@usgs.gov 

Akca Irfan Ankara University iakca@eng.ankara.edu.tr 

Baofeng Tian Jilin University tianbf@jlu.edu.cn 

Baroncini Turricchia Guido ITC-Twente University coprolog@yahoo.com 

Basokur Ahmet Tugrul Ankara University basokur@ankara.edu.tr 

Behroozmand Ahmad A. Aarhus University ahmad@geo.au.dk 

Bernard Jean Iris-Instruments iris@iris-instruments.com 

Boucher Marie IRD marie.boucher@ird.fr 

Chevalier Antoine UJF antoine.chevalier@ujfgrenoble.fr 

Chuandong Jiang Jilin University willianjcd@yahoo.com.cn 

Costabel Stephan BGR stephan.costabel@bgr.de 

Dalgaard Esben Aarhus University esben.dalgaard@geo.au.dk 

David Oliver Walsh David Vista-Clara davewalsh@vista-clara.com 

Dlubac Katherine University Stanford kdlubac@stanford.edu 

Dlugosch Raphael LIAG raphael.dlugosch@liaghannover.de 

Esben Auken Aarhus University esben.auken@geo.au.dk 

Felix Rubio University Madrid fm.rubio@igme.es 

Francés Alain Pascal ITC frances08512@itc.nl 



5

Girard Jean-Francois BRGM jf.girard@brgm.fr 

Grombacher Denys University Stanford denysg@stanford.edu 

Grunewald Elliot Vista-Clara elliot@vista-clara.com 

Günther Thomas LIAG thomas.guenther@liaghannover.de 

Hagensen Tom Feldberg Danish Ministry of the 

Environment 

tofha@nst.dk 

Huangjian Wu University Wuhan kdjf_025@126.com 

Irons Trevor USGS tirons@usgs.gov 

Jun Lin Jilin University Lin_jun@jlu.edu.cn 

Keating Kristina Rutgers University kmkeat@andromeda.rutgers.e 

du 

Knight Rosemary University Stanford rknight@stanford.edu 

Kuschel Lars BLM kuschel@blm-storkow.de 

Larsen Jakob Juul Aarhus University jjl@iha.dk 

Legchenko Anatoly IRD / LTHE anatoli.legtchenko@ird.fr 

Leite Orlando Iris-Instruments iris@iris-instruments.com 

Lubczynski Maciek ITC lubczynski@itc.nl 

Macnae James CSIRO james.macnae@rmit.edu.au 

Mavrommatis Andreas University Stanford andreasm@stanford.edu 

Mazzilli Naomi Université Montpellier mazzilli@msem.univmontp2.fr 

McDowell Andrew ABQMR mcdowell@abqmr.com 

Müller-Petke Mike LIAG mike.mueller-petke@liaghannover.de 

Nils Perttu Nils Luleå University of 

Technology 

nils.perttu@ltu.se 

Plata Juan University Madrid jl.plata@igme.es 

Qingming Duan Jilin University duanqm@jlu.edu.cn 

Radic Tino Berlin radic@radic-research.de 

Ronczka Mathias LIAG mathias.ronczka@liaghannover.de 

Roy Jean ITC jeanroy_igp@videotron.ca 

Ryom Nielsen Mette Rambøll A/S mrn@ramboll.dk 

Seibertz Klodwig Universität Halle klodwig.seibertz@student.unihalle.de 

Shengwu Qin Jilin University qinsw@jlu.edu.cn 

Shu-qin Sun Jilin University sunsq@jlu.edu.cn 

Shushakov Oleg Institute of Chemical 

Kinetics and Combustion 

SB RAS 

shushako@kinetics.nsc.ru 

Soltani Rafik University Beijing rafiksoltani2008@gmail.com 

Texier Benoit Iris-Instruments iris@iris-instruments.com 

Tie-hu Fan Jilin University fth@jlu.edu.cn 

Tingting Lin Jilin University ttlin@jlu.edu.cn 



6

Toke Højbjerg Nielsen Toke Højbjerg Aarhus University t.hojbjerg@gmail.com 

Troels Norvin Vilhelmsen Aarhus University troels.norvin@geo.au.dk 

Vermeersch Fabrice Iris-Instruments iris@iris-instruments.com 

Vouillamoz Jean-Michel Cotonou, Benin jean-michel.vouillamoz@ird.fr 

Walbrecker Jan University Stanford jan.walbrecker@stanford.edu 

Xiaofeng Yi Jilin University Yixiaofeng1985@126.com 

Yaramanci Ugur LIAG ugur.yaramanci@liaghannover.de 

Special Issue Publication 

There will be a special issue in “Near Surface Geophysics”, Journal of the European Association of 

Geoscientists & Engineers. 

This way, the tradition of the Magnetic Resonance workshops to produce a follow up peer review 

document will be continued. Details of previous special issues can be found at: 

http://www.mrs2012.org/ 

Participants are asked and encouraged to submit full papers derived from their workshop 

contributions. As usual, these will be subject to peer reviewing by support of scientific 

committee of the workshop. 



7

Scientific Program 

Tuesday, September 25th 

14.00 - 14.30 Opening Session 

14.30 - 15.30 Measurement Technology 1 

Title Speaker 

14.30 - 14.50 Novel Surface-NMR Pulse Sequences for Improved 

Estimation of Relaxation Times and Hydrogeologic 

Properties 

14.50 - 15.10 Design and Experimental study of Small MRS 

Antenna for Underground Applications 

Grunewald 

Xiaofeng 

15.10 - 15.30 Detection Coils for Near-Surface Earth’s Field NMR McDowell 

15.30 - 16.00 Coffee Break 

16.00 - 17.20 Measurement Technology 2 

16.00 - 16.20 Quantifying Background Magnetic Field 

Inhomogeneity Using Composite Pulses: 

Estimating T2 from T2* by Correcting for Static 

Dephasing 

Grombacher 

16.20 - 16.40 Modelling NMR signal for compact sensors Davis 

16.40 - 17.00 3 component NMR with NMARMIT sensors Macnae 

17.00 - 17.20 Development of a novel MRS-TEM combined 

instrument for improving MRS capacity in 

groundwater investigations 

Wednesday, September 26th 

8.40 - 10.00 Signal Processing 

8.40 - 9.00 Optimized Wiener filtering with the Numis Poly 

system 

9.00 - 9.20 Model-based cancelling of powerline harmonics 

in multichannel MRS recordings 

9.20 - 9.40 Joint use of adaptive notch filter and empirical 

mode decomposition for noise cancellation 

applied to MRS 

Modelling and Inversion 1 

9.40 - 10.00 The case for comprehensive frequency-domain 

inversion of surface NMR data 

Ting-Ting 

Dalgaard 

Larsen 

Baofeng 

Irons 



8

10.00 - 10.50 Coffee Break & Poster Session 

10.50 - 11.10 Inversion of T1 relaxation times based on pcPSR 

measurements - Synthetic examples 

11.10 - 11.30 Inversion of surface-NMR T1 data: results from 

two field sites with reference to borehole logging 

Müller-Petke 

Walbrecker 

11.30 - 11.50 Earth's magnetic field and MRS phase shift Legchenko 

11.50 - 12.10 Bloch-Siegert effect in MRS Shushakov 

Case Studies 1 

12.10 - 12.30 Exploiting the phase information: examples from 

the Netherlands 

12.30 - 14.00 Lunch 

14.00 - 15.40 

14.00 - 14.20 MRS and electrical prospection in the context of 

weathered peridotite rocks in the South of New 

Caledonia 



Roy 

Girard 

14.20 - 14.40 MRS and Borehole Correlation in Denmark Nielsen 

14.40 - 15.00 Implementation of MRS in the Danish National 

Groundwater management 

15.00 - 15.20 MRS study of water content variations in the 

unsaturated zone of a karst aquifer (southern 

France) 

15.20 - 15.40 Research on Gushing Disaster Detection in 

Tunnel with Magnetic Resonance Sounding 


16.00 Field Experiment 

18.30 Conference Evening 

Thursday, September 27th 

8.40 - 12.30 Modelling and Inversion 2 

8.40 - 9.00 2D Cell Inversion for Magnetic Resonance 

Tomography using JLMRS-Array Instrument 

9.00 - 9.20 2D qt-inversion to investigate spatial variations 

of hydraulic conductivity using SNMR 

9.20 - 9.40 Locating a karst conduit with 2D Monte Carlo 

inversion of magnetic resonance measurements 

9.40 - 10.00 A comprehensive study of the parameter 

determination in a joint MRS and TEM data 

analysis scheme 

Feldberg Hagensen 

Mazzilli 

Shengwu 

Chuandong 

Dlugosch 

Chevalier 

Behroozmand 

9

10.00 - 10.50 Coffee Break & Poster Session 

10.50 - 11.10 Hybrid and multi-objective genetic algorithm 

applications in MRS data inversion 

Advances in hydrological parameterization 1 

11.10 - 11.30 Recent advancements in NMR for characterizing 

the vadose zone 

11.30 - 11.50 Direct inversion for water retention parameters 

from MRS measurements in the 

saturated/unsaturated zone – a sensitivity study 

11.50 - 12.10 MRS subsurface parametrization for coupled 

hydrological Marmites model 

12.10 - 12.30 An efficient full coupled inversion of aquifer 

test, MRS and TEM data 

12.30 - 14.00 Lunch 

14.00 - 17.20 Advances in hydrological parameterization 2 

14.00 - 14.20 The integration of logging and surface NMR for 

mapping spatial variation in hydraulic 

conductivity 

14.20 - 14.40 Hard rock hydrogeophysics applied to 

hydrological model parameterization - Sardón 

catchment case study (Salamanca, Spain) 

14.40 - 15.00 A laboratory study to determine the effect of 

surface roughness and grain diameter on NMR 

relaxation rates of glass bead packs. 

15.00 - 15.20 A numerical study of the relationship between 

NMR relaxation and permeability in materials 

with large pores 


Case Studies 2 

15.40 - 16.00 NMR Logging: A tool for quantifying effective 

porosity and hydraulic conductivity within the 

Murray Darling Basin of Australia 

16.00 - 16.20 Feasibility study of the MRS monitoring in a 3D 

hydrogeological structure: aquifer recharge 

from a pond in the Sahel (Niger) 

16.20 - 16.40 Investigating hydraulic properties of a glacial 

sand deposit in the north of Sweden 

16.40 - 17.00 Estmating regional groundwater reserve in a 

clayey sandstone aquifer of Cambodia 

17.00 - 17.20 The Applications of MRS for detection of 

Groundwater-induced disasters , in China 



Akca 

Walsh 

Costabel 

Baroncini- 

Turricchia 

Vilhelmsen 

Knight 

Francés 

Keating 

Dlubac 

Abraham 

Boucher 

Pertuu 

Vouillamoz 

Jun 

10

Poster 

Measurement Technology Poster 

Aquater MRS instrument Shushakov 

Signal Processing Poster 

Higher-Order Statistical Signal Processing for Surface-NMR 

Electronic Instruments 

MRS noise investigations with focus on optimizing the 

measurement setup in the field 

Soltani 

Costabel 

A comparison of harmonic noise cancellation concepts Müller-Petke 

Identification and elimination of spiky noise features in MRS 

data 

Modelling and Inversion Poster 

Costabel 

Experimental verification of a 3D model for MRS Legchenko 

MRSMatlab – a toolbox for modeling, processing, and inverting 

surface-NMR data 

Comparison of borehole and surface NMR-inferred water 

content profiles 

Müller-Petke 

Mavrommatis 

Study on Factors Affecting SNMR Vertical and Lateral Resolution Yan 

Researching vertical resolution of SNMR by using numerical 

simulation 

Advances in hydrological parametrization Poster 

Research and Practice of the Relationship between 

MRS Inversion Parameters and the Water Yield 

Quantitative aquifer system characterization on Borkum island 

using joint inversion of MRS and VES data 

A general model for predicting hydraulic conductivity of 

unconsolidated material using nuclear magnetic resonance 

Case Studies Poster 

Case studies of the MRS method in various geological 

backgrounds 

Usage of Magnetic Resonance Sounding (MRS) for attaining 

hydrogeological profiles (Havelland, Brandenburg) 

Assessment of the use of surface NMR to detect internal 

erosion and piping in earthen embankments 

Characteristics and Examples of MRS Signals in Good Conductive 

Areas 

The Experimental Study of MRS Method in Plateau Permafrost 

Region 

Joint use of MRS and TDEM for characterizing groundwater 

recharge in the Lake Chad basin 

Calibration MRS Hydrodynamic Parameters Measurements from 

Pumping Tests in Inner-Mongollia of China 

Application of surface-NMR to study unfrozen sediments below 

lakes in permafrost regions 

Surface NMR applied to determining aquifer properties in the 

Central Platte River, central Nebraska 



Peng 

Wang 

Günther 

Dlugosch 

Bernard 

Seibertz 

Irons 

Wang 

Zhang 

Boucher 

Sun 

Parsekian 

Abraham 

11

Abstracts 

Content 

Measurement Technology ....................................................................................................... 15 

Novel Surface-NMR Pulse Sequences for Improved Estimation of Relaxation Times and Hydrogeologic 

Properties .................................................................................................................................................... 16 

Design and Experimental study of Small MRS Antenna for Underground Applications ............................. 17 

Detection Coils for Near-Surface Earth’s Field NMR ................................................................................... 18 

Quantifying Background Magnetic Field Inhomogeneity Using Composite Pulses: Estimating T2 from T2* 

by Correcting for Static Dephasing .............................................................................................................. 19 

Modelling NMR signal for compact sensors ................................................................................................ 20 

3 component NMR with NMARMIT sensors ............................................................................................... 21 

Development of a novel MRS-TEM combined instrument for improving MRS capacity in groundwater 

investigations .............................................................................................................................................. 22 

Aquater MRS instrument............................................................................................................................. 23 

One-Dimensional Theoretical Research on MRS Excited by Finite Current Wire ....................................... 24 

Signal Processing ............................................................................................................................. 25 

Optimized Wiener filtering with the Numis Poly system ............................................................................ 26 

Model-based cancelling of powerline harmonics in multichannel MRS recordings ................................... 27 

Joint use of adaptive notch filter and empirical mode decomposition for noise cancellation applied to 

MRS ............................................................................................................................................................. 28 

Higher-Order Statistical Signal Processing for Surface-NMR Electronic Instruments ................................. 29 

Identification and elimination of spiky noise features in MRS data ........................................................... 30 

MRS noise investigations with focus on optimizing the measurement setup in the field .......................... 31 

A comparison of harmonic noise cancellation concepts ............................................................................. 32 

Modeling and Inversion ............................................................................................................. 33 

The case for comprehensive frequency-domain inversion of surface NMR data ....................................... 34 

Inversion of T1 relaxation times based on pcPSR measurements - Synthetic examples ............................ 35 

Inversion of surface-NMR T1 data: results from two field sites with reference to borehole logging ......... 36 

Earth's magnetic field and MRS phase shift ................................................................................................ 37 

Bloch-Siegert effect in MRS ......................................................................................................................... 38 

2D Cell Inversion for Magnetic Resonance Tomography using JLMRS-Array Instrument .......................... 39 

2D qt-inversion to investigate spatial variations of hydraulic conductivity using SNMR ............................ 40 



12

Locating a karst conduit with 2D Monte Carlo inversion of magnetic resonance measurements ............. 41 

A comprehensive study of the parameter determination in a joint MRS and TEM data analysis scheme. 42 

Hybrid and multi-objective genetic algorithm applications in MRS data inversion .................................... 43 

Experimental verification of a 3D model for MRS ....................................................................................... 44 

Comparison of borehole and surface NMR-inferred water content profiles.............................................. 45 

MRSMatlab – a toolbox for modeling, processing, and inverting surface-NMR data ................................ 46 

Researching vertical resolution of SNMR by using numerical simulation ................................................... 47 

Study on Factors Affecting SNMR Vertical and Lateral Resolution ............................................................. 48 

Advances in hydrological parameterization................................................................. 49 

Recent advancements in NMR for characterizing the vadose zone ........................................................... 50 

Direct inversion for water retention parameters from MRS mea-surements in the saturated/unsaturated 

zone – a sensitivity study ............................................................................................................................ 51 

MRS subsurface parametrization for coupled hydrological Marmites model ............................................ 52 

An efficient full coupled inversion of aquifer test, MRS and TEM data ...................................................... 53 

The integration of logging and surface NMR for mapping spatial variation in hydraulic conductivity ...... 54 

Hard rock hydrogeophysics applied to hydrological model parameterization - Sardón catchment case 

study (Salamanca, Spain)............................................................................................................................. 55 

A laboratory study to determine the effect of surface roughness and grain diameter on NMR relaxation 

rates of glass bead packs. ............................................................................................................................ 57 

A numerical study of the relationship between NMR relaxation and permeability in materials with large 

pores ............................................................................................................................................................ 58 

A general model for predicting hydraulic conductivity of unconsolidated material using nuclear magnetic 

resonance .................................................................................................................................................... 59 

Quantitative aquifer system characterization on Borkum island using joint inversion of MRS and VES data 

..................................................................................................................................................................... 60 

Research and Practice of the Relationship between MRS Inversion Parameters and the Water Yield ...... 61 

Case studies ........................................................................................................................................ 62 

Exploiting the phase information: examples from the Netherlands ........................................................... 63 

MRS and electrical prospection in the context of weathered peridotite rocks in the South of New 

Caledonia. .................................................................................................................................................... 64 

MRS and borehole correlation in Denmark................................................................................................. 65 

Implementation of MRS in the Danish National Groundwater management ............................................ 66 

Feasibility study of the MRS monitoring in a 3D hydrogeological structure: aquifer recharge from a pond 

in the Sahel (Niger) ...................................................................................................................................... 67 

Research on Gushing Disaster Detection in Tunnel with Magnetic Resonance Sounding ......................... 68 

NMR Logging: A tool for quantifying effective porosity and hydraulic conductivity within the Murray 

Darling Basin of Australia ............................................................................................................................ 69 

MRS study of water content variations in the unsaturated zone of a karst aquifer (southern France) ..... 70 



13

Investigating hydraulic properties of a glacial sand deposit in the north of Sweden ................................. 71 

Estmating regional groundwater reserve in a clayey sandstone aquifer of Cambodia. ............................. 72 

Application of underground magnetic resonance sounding on advanced detection water-induced disaster 

in 3D structure ............................................................................................................................................. 73 

Surface NMR applied to determining aquifer properties in the Central Platte River, central Nebraska .... 74 

Case studies of the MRS method in various geological backgrounds ......................................................... 75 

Joint use of MRS and TDEM for characterizing groundwater recharge in the Lake Chad basin ................. 76 

Assessment of the use of surface NMR to detect internal erosion and piping in earthen embankments . 77 

The Applications of MRS for detection of Groundwater-induced disasters , in China ............................... 78 

Application of surface-NMR to study unfrozen sediments below lakes in permafrost regions ................. 79 

Usage of Magnetic Resonance Sounding (MRS) for attaining hydrogeological profiles (Havelland, 

Brandenburg) .............................................................................................................................................. 80 

Calibration MRS Hydrodynamic Parameters Measurements from Pumping Tests in Inner-Mongollia of 

China ............................................................................................................................................................ 81 

Characteristics and Examples of MRS Signals in Good Conductive Areas .................................................. 82 

The Experimental Study of MRS Method in Plateau Permafrost Region .................................................... 83 



14

Measurement Technology 



15

Novel Surface-NMR Pulse Sequences for Improved Estimation of Relaxation Times and 

Hydrogeologic Properties 

Novel Surface-NMR Pulse Sequences for Improved Estimation of Relaxation 

Times and Hydrogeologic Properties 

Elliot Grunewald and David Walsh 

Vista Clara, Inc., Mukilteo, Washington, USA 

elliot@vista-clara.com 

Deriving robust estimates of hydrogeologic 

properties from NMR methods requires the 

ability to accurately measure relaxation times 

that are sensitive to aquifer properties. While 

conventional surface-NMR (SNMR) freeinduction 

decay (FID) methods reliably 

measure the effective transverse T2* relaxation 

time, this parameter is often dominated by 

influences from magnetic geology. The 

longitudinal T1 and transverse T2 relaxation 

times are known to exhibit more robust links to 

permeability, but proposed approaches to 

measuring these parameters have shown 

considerable limitations. For example, the 

pseudo-saturation-recovery (PSR) experiment 

for assessing T1 yields a challenging and nonlinear 

inversion kernel, while the Hahn-spinecho 

(HSE) for measuring T2 is often still 

corrupted by magnetic influences. Recognizing 

these limitations, we have developed new 

paradigms for pulse sequences to quantify T1 

and T2. A new “crush-recovery” (CR) 

sequence for measuring T1 utilizes two pulses: 

a first “crushing” pulse of fixed amplitude and 

a second, smaller “depth-profiling” pulse with 

an amplitude varied between measurements. 

The first pulse does not generate true 

saturation (i.e., 90 o tip angles); rather, this 

initial pulse acts to decoherently scatter the 

magnetization spatially leaving an effective 

saturated condition of zero net longitudinal 

magnetization over a range of shallow to 

intermediate depths. The second pulse, applied 

after a short delay, is used to profile, as a 

function of depth, the magnetization that 

recovers by T1 within this crushed zone. The 

CR approach has many advantages to the PSR, 

as we demonstrate in synthetic and real field 

experiments. A fixed amplitude for the 

crushing pulse provides constant initial 

conditions, so signals recorded after the second 

pulse can be inverted using the standard 

SNMR imaging kernel. Given a complete CR 

data set acquired for multiple delay times, the 

inversion yields both T1 and T2* as a function 

of depth. Further, unique expression of the 

covariance of these times is exploited to obtain 

2D T1-T2* mapped distributions. The CR 

approach, however, does share some common 

limitations with all previously demonstrated 

SNMR pulse sequences. Specifically, the 

duration of the recorded signals are 

fundamentally constrained by the duration of 

T2*, and all double-pulse sequences for T1 or 

T2 require repeated experiments with varied 

interpulse delay times. Ultimately, these 

factors result in very long acquisition times, 

especially for conditions of low SNR and short 

T2*. We overcome all these limitations with 

the first-ever development and field 

demonstration of a SNMR CPMG sequence. 

As in borehole CPMG measurements, this new 

approach uses a train of N appropriately phasecycled 

pulses to produce a train of N-1 echoes 

in a single record. We present real CPMG 

field data, including one dataset in which six 

echoes are recorded a single one-second long 

measurement. These data yield robust 

determination of T2 versus depth in greatly 

reduced acquistion times and with limited 

sensitivity to magnetic geology that may 

potentially be used to probe fluid diffusion 

dynamics. These developments and continued 

advancements in pulse sequences will provide 

substantial improvements in groundwater 

characterization by non-invasive SNMR. 



16

Design and Experimental study of Small MRS Antenna for Underground Applications 

Design and Experimental study of Small MRS Antenna for Underground 

Applications 

Yi Xiaofeng, Lin Jun, Duan Qingming, Wang Yingji, Fan Tiehu 

College of Instrumentation and Electrical Engineering / Key laboratory of Geo-exploration Instrumentation, Ministry of 

Education, Jilin University, Jilin 130061,China 

Lin_jun@jlu.edu.cn; Yixiaofeng1985@126.com 

Tunnel traffic, coal mining or other 

underground facilities constructions would 

induce , water inrush, gushing mud or collapse 

water disease problem. This worldwide crisis 

could cause serious accidents, and even 

catastrophic consequences. By restriction of 

complex geology and hydrology condition, the 

traditional methods, such as TSP, TRT, TST 

and TEM cannot directly detect the water 

disaster because of its own principle limit. 

MRS technology as a direct detection method 

for water plays an important role on 

groundwater engineering. As MRS signal is 

produced uniquely by water, multiplicity of 

solutions can not exist. And its measurement 

process has advantages of high speed, high 

accuracy, abundant information and can 

indicate the water bursting accident type, 

enabling this method has a good development 

prospect in underground disaster water 

forecast . 

To date, the research of small coil for MRS 

just begins. Jesus Diaz-Curiel etc have used an 

octagon coil with side of 6 meter or 10 meter 

to detect shallow and very shallow 

groundwater. However the coil diameter is not 

small enough for most of the underground 

cases. J.M. Greben etc have used 2 meter 

square coil for advanced detection water in 

mine, unfortunately because of some 

conditions restrict, this coil did not receive 

MRS signal. Based on the above researches, a 

design and optimization method for MRS 

detection antenna applying for the demarcate 

space as tunnel and mining is introduced in this 

paper. By improving the property parameters 

of coil, we could enhance the received ability 

of small MRS antenna and strengthen the 

magnetic field. The improved equipment has 

been used to field measurement on a 

simulation site, and the results prove the 

validity of small MRS antenna design method. 

As the transimtter and receiver coils are 

separated, they are designed independently to 

satisfy individual requirements in furthest. For 

design of receiver coil, using the unique 

multilayer coil enwinding form can reduce the 

coil impedance parameters and improve the 

coil transfer characteristics. The simulation 

tests confirmed that this method can make the 

transfer coefficient increases to 7.2 and 4.6 for 

a coil with diameter of 6 meter and 2 meter, 

respectively, which meets the requirements of 

MRS signal receiver in tunnel or mine. For 

design of transimitter coil, a transimitter 

system is constructed of multiple layers of 

independent coil, which uses the layered driver 

way to strengthen small coil excitation field 

energy efficiency and improve the quality of 

transmitter waveform. The experiments 

confirm that the energy utilization ratio for a 

coil of 6 meter diameter is improved from 0.35 

to 0.57, rectangular coefficient reaches 0.85 

and t for a coil of 2 meter diameter, the energy 

utilization ratio is improved from 0.24 to 0.49, 

rectangular coefficient reaches 0.78. 

Base on the commercial JLMRS-I instrument 

we improved and optimize the measurement 

system. A field test in Changchun, has then 

been conducted using the improved apparatus.. 

Detection results show that the coil 

optimization design method can get effective 

MRS signal from a certain depth of 

groundwater. The proposed design method and 

conclusions provide guidance for the coil 

design and instrument optimal in limited 

measuring space and a new possibility to 

expand the application range of MRS 

technology. 

References 

Greben J M, Meyer R, Kimmie Z. The underground 

application of Magnetic Resonance Soundings[J]. 

Journal of Applied Geophysics, 2011,75: 220-226. 

Jesús Díaz-Curiel, Bárbara Biosca, Lucía Arévalo,et 

al.Development of field techniques for improving 

MRS quality in shallow investigations.Near Surface 

Geophysics,2011,9:113-121. 

Xue Guo-Qiang,LI Xiu. The technology of TEM tunnel 

prediction imaging. Chinese Journal of Geophysics, 

2008,51(3)894:900 



17

Detection Coils for Near-Surface Earth’s Field NMR 

E. Fukushima, A. F. McDowell, T. Z. Zhang, S. A. Altobelli 

ABQMR, Albuquerque, New Mexico, USA 

mcdowell@abqmr.com 

At present, Earth’s Field NMR from the 

surface of the Earth (that is, Surface NMR) is 

used to detect significant volumes of water or 

organic pollutants at depths roughly 

comparable to the coil’s horizontal extent. 

However, there are applications that require 

the detection signals from shallower depths. 

For example, the detection of oil that has 

escaped under Artic sea ice, or the 

determination of soil water content in the 

vadose zone. The usual Surface NMR 

detection coils are not particularly suited for 

these shallower depths; improvements that 

yield increases in both SNR and depth 

resolution are needed. 

We have developed a new flat coil design to 

address these issues. In traditional high field 

NMR, there have been many attempts to 

optimize coils designs for unilateral 

applications and, in addition, to flat, thin, 

samples or sampled regions. The common 

simple loop is optimal for a sample region that 

is approximately a radius away from the loop, 

thus not ideally suited for a very thin sample 

region, close to the coil. The meanderline coil 

can have good senetivity and position 

resolution, but it is designed for flat samples 

oriented along the static field, not the 

orientation that is common for EFNMR. An 

improved coil should have a flat, sensitive 

region that is close to the coil with high and 

flat specific sensitivity profile. 

Our coil consists of physically parallel wires 

connected in series and spread out over a flat 

substrate. The current return wires are placed 

on the same substrate but displaced to the sides 

to minimize their contributions to the sensitive 

region of the coil. We have built an example 

of such a coil having 82 parallel wires in the 

center with the return wires bundled at the 

edges of the ~1 meter square plywood 

substrate. A single turn of the coil is 

topologically a figure-8, with the loops of the 8 

taking the form of rectangles. The two straight 

segments in the center constitute two of the 

multiple parallel wires of the flat coil. A 

Detection Coils for Near-Surface Earth’s Field NMR 

simple extension to a two-turn figure-8 results 

in four parallel wires in the central region of 

the coil. For the 82 wire model coil, each 

straight wire is displaced on the plywood so 

nearly the entire board is covered. 

This 1 m 2 coil has been used in the field to 

detect EFNMR signals from water placed 

directly on top of the coil structure. These 

detections typically require only a few minutes 

to achieve. The sentivitiy of the coil drops 

with distance from the coil structure, so the 

detection of signals from the sub-surface will 

require larger coils. The sensitivity profile of 

the coil is relatively flat for depths small 

compared to the lateral extent of the coil, a 

property which will enable depth profiling. 

Alternatively, the flat sensitivity profile can be 

used to optimize the coil for the detection of a 

thin layer of oil floating on water under ice. 

A virtue of the flat coil consisting of multiple 

figure-8 windings is its relative immunity to 

magnetic interference such as from distant 

power lines. The sensitivity to interference can 

be adjusted after placement of the coil by 

either moving the wires or by adjusting 

conducting paddles in the spaces between the 

main wires and the returns. 

This project is funded by Exxon Mobil Upstream 

Research Company to develop technology to detect 

spilled/leaked oil caught under Arctic sea ice. We 

also acknowledge assistance in coil winding and 

testing by J. Bench, D. Kuethe, and N. Sowko. 



18

Quantifying Background Magnetic Field Inhomogeneity Using Composite Pulses: 

Estimating T2 from T2* by Correcting for Static Dephasing 

Quantifying Background Magnetic Field Inhomogeneity Using Composite 

Pulses: Estimating T2 from T2* by Correcting for Static Dephasing 

Denys Grombacher 1 , Jan O. Walbrecker 1 , Rosemary Knight 1 

1 Department of Geophysics, Stanford University 

denysg@stanford.edu 

Surface Nuclear Magnetic Resonance (SNMR) 

measurements typically involve the 

application of a single perturbing B1 pulse and 

the monitoring of the spin magnetization’s 

subsequent return to equilibrium. This 

measured decay, called the free induction 

decay (FID), is governed by the relaxation time 

T2*. Although T2* contains information about 

the surface area to volume ratio (S/V), it 

remains very susceptible to dephasing caused 

by the presence of background magnetic field 

inhomogeneity. This dephasing mechanism 

decreases the sensitivity of T2* to S/V. 

Grunewald and Knight (2011) have 

demonstrated that in many cases T2* does not 

carry sensitivity to S/V. This may lead to 

errors when using T2* to estimate hydraulic 

conductivity, as the relation between relaxation 

times and hydraulic conductivity is based on 

the underlying assumption that the relaxation 

times carry a direct link to S/V. 

In order to allow for the estimation of S/V 

from an FID measurement, we develop a 

methodology to quantify, and correct for, the 

component of the measured FID that is due to 

dephasing. A suite of composite pulses is 

designed to characterize the inhomogeneity of 

the background magnetic field. By inverting 

the variation of the FID amplitude and phase 

following each composite pulse, we are able to 

predict the background magnetic field 

distribution. We use the predicted field 

distribution to quantify and remove the 

component of static dephasing present in the 

measured FID. This allows the T2 decay, 

which can be related to S/V, to be predicted 

using only FID measurements. 

Each composite pulses utilized in this study 

consist of two individual pulses and is defined 

by 1) the flip angle of each individual pulse, 2) 

the delay time between pulses, and 3) the 

relative phase of the two pulses. By limiting 

ourselves to two pulses we retain 

compatiibility with SNMR. We used a suite of 

11 composite pulses was used to predict the 

background magnetic field distribution for 

several samples in a controlled laboratory 

environment. For all samples, the predicted T2 

distributions (after correcting for dephasing) fit 

much more closely the true T2 distribution 

(measured using a CPMG) than do the T2* 

distributions (from FID measurements). This 

methodology may provide a means of 

correcting for the static dephasing that arises 

due to background field inhomogeneity, 

potentially leading to subsequent 

improvements in the reliability of hydraulic 

conductivity estimates from SNMR. 

References 

Grunewald, E., Knight, R. (2011): The effect of 

pore size and magnetic susceptibility on the 

surface NMR relaxation parameter T2*. Near 

Surface Geophysics, 9. 



19

Modelling NMR signal for compact sensors 

Aaron Davis and James Macnae 

CSIRO and RMIT Universivty 

aaron.davis@csiro.au and james.macnae@rmit.edu.au 

Recent advances have increased the signal to 

noise ratio of EM B and dB/dt sensors 

remarkably. By tuning sensors for the low 

frequencies appropriate to earth-field NMR 

signal, it is theoretically possible to use them 

in geophysical applications for the 

invesitgation of groundwater in the subsurface 

of the earth. In this paper, we model the 

response of compact B and dB/dt sensors such 

as the 'NMARMIT' sensor (Macnae, 2012). 

We revisit the work of Weichman et al (2000) 

to generalise the theory of surface NMR to 

account for compact sensors arrayed on the 

surface of the earth. Our theory is appropriate 

for any loop shape and conductivity structure. 

By simultanoeusly monitoring the current 

pulse of the transmit loop and the NMR 

response in B and dB/dt, we demonstrate the 

theoretical feasability of these sensors to 

Modelling NMR signal for compact sensors 

measure NMR signal in three dimensions with 

zero delay time. 

Through forward modelling of the physical 

response, we show that deployment of sensor 

arrays can be used to detect complex 

distribution of water in the earth; and that it 

* 

should be possible to measure both T1 and T 2 

in a routine NMR tomography measurement in 

the same time that it takes to do a conventional 

sNMR sounding. 

References 

Macnae, J, 2012. A new generation of EM sensors, 

ASEG conference extended abstracts, Brisbane. 

Weichman, P.B., Lavely, E.M., and Ritzwoller, 

M.H., 2000. Thoery of surface nuclear magnetic 

resonance with applications to geophysical 

imaging problems: Physical Review E, 62, 1, 

1290–1312. 



20

3 component NMR with NMARMIT sensors 

Janmes Macnae & Aaron Davis 

RMIT University and CSIRO 

James.macnae@rmit.edu.au & aaron.davis@csiro.au 

Recent developments in mineral exploration 

have shown that compact B and dB/dt sensors 

(in particular the ARMIT sensor designed at 

RMIT University with funding from Abitibi 

Geophysics) based on monitoring currents in a 

perfect conductor can achieve lower noise 

levels than High Temperature SQUIDS. 

(Macnae, 2012). Noise levels achieved around 

2 kHz are roughly equivalent to those in the 

large loops commonly used as NMR receivers, 

with sensitivities better than 100fT. 

Optimisation of these sensors for the NMR 

bandwidth and signals has produced the 

“NMARMIT” sensor. 

The NMARMIT sensor measures 

simultaneously B and dBdt signals, with the 

respective gains adjusted to ouput similar 

voltages for 1 kHz signals. They are effectively 

linear, and do not require any “recovery time’ 

after saturation. They are thus suitable for 

field use for recording low amplitude NMR 

signals immediately after the transmission 

pulse 

With careful alignment, horizontal component 

receivers are null-coupled to the primary 

magnetic field of a nearby (coplanar and 

perfectly horizontal) transmitter. This nullcoupling 

allows in theory continuous recording 

of the secondary NMR response during proton 

excitation (spin-up) and decay (spin down) 

without the “dead-time” when the same loop is 

used for transmission and sensing. In practice, 

coupling is never perfect, and some primary 

signal is seen in secondary recordings. 

3 component NMR with NMARMIT sensors 

The first tests of the sensors (all 3 components, 

measuring B and dB/dt) in Australia with a 

low-amplitude pulsed waveform transmitter 

have shown that they may be capable of 

detecting NMR signals associated with nearsurface 

water, and could map 2D changes 

around the edge of a dam surrounded by a 

transmitter. Further tests with more powerful 

NMR transmitters are planned in the very near 

future. 

The new sensors, being compact and 

inexpensive, can be arranged in an array, 

allowing detailed spatial mapping of secondary 

NMR fields from each transmitter layout. 

Using existing instruments such as 

SmartEM24, up to 16 sensors can be 

simultaneously sampled. With 3 spatial 

components being sampled, it may be possible 

to separate T1 from T2* signals through 

resolving the spatial orientation of the source 

proton dipole moments. 

Modelling (companion paper by Davis and 

Macnae, this conference) suggests that 

significant increases in (a) vertical and spatial 

resolution of water and (b) survey productivity 

will occur if the use of the distributed 

NMARMIT sensors are used. 

References 

Macnae, J, 2012, A new generation of EM sensors, 

ASEG conference extended abstracts, Brisbane 



21

Development of a novel MRS-TEM combined instrument for improving MRS capacity in 

groundwater investigations 

Development of a novel MRS-TEM combined instrument for improving 

MRS capacity in groundwater investigations 

Lin Ting-ting, Wan Ling, Shang Xin-lei, Shi Wen-long, Lin Jun 

College of Instrumentation and Electrical Engineering, Jilin University, Changchun, 130061, China 

ttlin@jlu.edu.cn ; cc56788@163.com 

In this paper we outline the technical 

specifications and capabilities of the MRS- 

TEM combined system. We initially 

demonstrate the high efficiency of the novel 

MRS-TEM instrument and its working models. 

Specifically, the joint inversion scheme of both 

MRS and TEM data sets for detecting shallow 

and deeper aquifers (>150 m) were 

demonstrated in detail. This algorithm is used 

for enhancing spatial resolution to a 

quantitative interpretation of the groundwater 

contents than using each method respectively. 

Finally, we present the results of some recent 

groundwater investigations conducted in China 

and Mongolia. 

Instrumentation 

The combined groundwater detection system is 

designed based on the principles of magnetic 

resonance sounding (MRS) and transient 

electromagnetic (TEM). Both MRS module 

and TEM module are integrated within one 

instrument container. They compatibly share 

one ADC, one DC-DC convertor and one CPU 

to accomplish individual function. Aslo, a 

designed FPGA is capable of generating each 

transmit time sequence. Hence, by using 

different combinations of Tx/Rx loops, high 

working effeiciency for 1D/2D groundwater 

investigation could be expected when 

switching working status. 

When working at MRS mode, the 

excitation pulse moment of the transmitter can 

exceeds to 20000 A·ms with 40ms of transmit 

time, allowing the instrument produces 

maximum AC current pluses in excess of 500 

A. Additionally, by using special design of 

bilateral diode, the dead-time of this instrument 

can be shortened to a minimum value of 17ms. 

The receiver circuit background noise is 1 

nV/sqrt (Hz) at 100Hz. 

The maximum detection depth could be 

reached to 300m when the instrument works at 

TEM mode. The turn off time is decreased to 

1µs, enabling plenty of information to be 

received for the post data interpretation. 

Joint inversion algorithms 

Initially, the MRS response curves were 

inverted using half-spaces with the resistivities 

of 500Ωm, 100 Ωm, 50Ωm, 10Ωm, and 1Ωm, 

respectively. This step allows estimation of the 

error in determine the water content caused by 

the changes of the resistivity of the subsurface. 

The water content and layer boundaries are 

then determined for the first time by the block 

method. With the fix thickness to be the initial 

parameters of the TEM inversion method, the 

resisitivities of the aquifer could be reached 

after repeated iteration. The forward kernel 

function was then caculated with the update 

resisitivities as well as the layer boundaries. 

The iteration process could be terminated until 

the calculate rms of both methods is below the 

minimum corresponding value. Simulation of 

the two-six layer results show the new 

inversion schemes can separate water bearing 

layers with accuracy depth. 

Field example 

Experimental results are presented for recent 

MRS-TEM groundwater investigations 

conducted in China and Mongolia. 

References 

Braun, M., Yaramanci, U. (2008) : Inversion of 

resistivity in Magnetic Resonance Sounding. 

Journal of applied geophysics, 66(3-4): 151-164. 

Chalikakis, K., Nielsen, M.R., Legchenko, 

A.(2008) MRS applicability for a study of glacial 

sedimentary aquifers in Central Jutland, 

Denmark. Journal of applied geophysics, 66(3- 

4): 176-187. 

Legchenko, A., Ezersky, M., Camerlynck, C. 

(2009): Joint use of TEM and MRS methods in a 

complex geological setting. Comptes rendus 

geoscience, 341(10-11):908-917. 

Lin, J., Duan, Q.M., Wang, Y.j.(2009): A 

instrument with nuclear magnetic resonance 

and TEM and their methods. China patent 

200610017226.8 



22

Aquater MRS instrument 

Oleg A. Shushakov 1, 2 , Dmitry L. Bizyaev 3 , Dmitry B. Poluboyarov 3 

1) Institute of Chemical Kinetics and Combustion SB RAS, Novosibirsk, Russia 

2) Novosibirsk State University, Novosibirsk, Russia 

3) Center of manufacturing application LTD 

aquater@ngs.ru 

The magnetic-resonance sounding (MRS) or 

the surface nuclear magnetic resonance 

(SNMR) can be used to unambiguously detect 

subsurface water in suitable geological 

formations (aquifers) down to a depth of the 

order of 100 meters depending on the antenna 

size, formation electrical conductivity, 

resonant frequency, and the presence of natural 

or cultural electromagnetic noise. 

Mathematical routines yield depth distributions 

of water, provided that water is present in 

horizontal layers, namely in its pores or 

fractures. Determination of pore size 

distributions is possible using MRS relaxation 

time measurement. The frequency of magnetic 

resonance in the case being considered 

amounts to several kilohertz, the dead time of 

the instrumentation – several milliseconds or 

tens of milliseconds. Water in extremely small 

pores of water-resisting rocks (e.g., in 

argillaceous grounds), chemically bound, 

crystallization or frozen water has smaller 

times of spin relaxation and is not registered. 

Weston Anderson from Varian Associates 

first introduced the surface NMR method [1]. 

Semenov et al. first designed the MRS tool [2]. 

The first MRS instrument, the Hydroscope has 

been made in late 80th at the Institute of 

Chemical Kinetics and Combustion, 

Novosibirsk, Russia [3]. 

The NUMIS (IRIS Instruments, Orleans, 

France) first made in late 90th is the most 

widely used MRS instrument [4]. 

Output 250A*40ms 

(150m circle, 

2500Hz) 

Aquater MRS instrument 

Hidroscope NUMIS Poly 



600A*40ms 

(100m 

square, 

frequency-?) 

Power supply 4x12V 2x12V 

Weight (kg) 100 105 

Max. depth of 

prospecting (m) 

120 150 

Table 1. Basic parameters of the Hydroscope and 

NUMIS instruments. 

Table 1 compares the basic parameters of the 

modern Hydroscope and NUMIS instruments. 

Nevertheless, 15 years (or even 25 years) of 

the MRS application displayed a number of 

significant problems: 

1) sensitivity to electromagnetic noise; 

2) insufficient depth of prospecting; 

3) incorrect physical model used both in 

the NUMIS and in the Hydroscope. 

Research is underway to determine if the MRS 

instruments currently used can be modified to 

solve these problems. The novel Aquater MRS 

instrument is introduced. 

References 

1. Varian R.H. (1962) Ground liquid prospecting 

method and apparatus. US. Patent 3019383. 

2. Semenov A.G., Pusep A.Yu., and Schirov M.D. 

(1982) Hydroscope - an installation for 

prospecting without drilling. Preprint USSR 

Acad. Sci., Novosibirsk, 26 pp. (in Russian). 

3. http://www.kinetics.nsc.ru/results/paper47.html 

4. http://www.irisinstruments.com/Product/Brochure/Numis.html 

23

One-Dimensional Theoretical Research on MRS Excited by Finite Current Wire 

One-Dimensional Theoretical Research on MRS Excited by Finite Current 

Wire 

Yuanjie Li, Zhenyu Li, Jianwei Pan, Jiagang Zhang, Hao Liu, Kai Wang 

Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan, PRC 

liyuanjie305@163.com 

Magnetic Resonance Sounding, abbreviated as 

MRS, is a novel geophysical technic specially 

designed for direct water exploration by using 

NMR phenomena. At present, in the fields a 

large loop normally acts as both transmitter 

and receiver, and in this model information of 

aquifers in varied depth from the shallow to the 

deep will be obtained through amplifying 

stimulating pulse. However, this traditional 

work mode has shortcomings of intense labour 

of the operator, great influence from landform, 

only one-dimensional information of aquifers 

being achieved, and finite maximum depth of 

investigation which is a problem to be solved 

urgently. These drawbacks may be related to 

field source that is the magnetic field of the 

loop, so, we propose a pioneering and bold 

assumption that the stimulating loop is 

superseded by finite current wire as the field 

source. In theory, the new mode possesses few 

advantages of flexible lay-pattern, free from 

tomography limitation, affluent information 

about underground aquifer, potential research 

in detecting depth. Therefore, we will do 

research about MRS methods excited by finite 

current wire, and determine its feasibility. 

The distributing of magnetic field stimulated 

by finite current line is numerical simulated in 

the homogeneous half-space, while its 

characteristics will be quantitatively analysed. 

And then various aquifers models in the mode 

of MRS method excited by wire source will be 

built to acquire NMR signals, characteristics of 

which will be compared with those in the 

traditional mode. By doing so ,it is can be 

concluded that it is feasible to employ line 

source exciting MRS technique , and also the 

superiority of this new method over 

conventional mode can be demonstrated. To 

perfect one-dimensional theoretical system of 

MRS method stimulated by line source, 

appropriate inversion about new method will 

be carried out. 

References 

Anderson, W.L.. (1979): Numerical integration of 

related Hankel transforms of order 0 and 1 by 

adaptive digital filtering. Geophysics, 44(10): 

1287-1305. 

Anderson, W.L.. (1984): Computation of Green's 

tensor integrals for three-dimensional 

electromagnetic problems using fast hankel 

transforms. Geophysics, 49(10): 877-901. 

Baltassat, J., A.V. Legchenko. (2002): Nuclear 

magnetic resonance as a geophysical tool for 

hydrogeologists. Journal of Applied Geophysics, 

50(1-2): 21-46. 

Braun, M., U. Yaramanci. (2011): Evaluation of the 

Influence of 2-D Electrical Resistivity on 

Magnetic Resonance Sounding. Journal of 

Environmental & Engineering Geophysics, 

16(3): 95-103. 

Guillen, A., A.V. Legchenko. (2002): Inversion of 

surface nuclear magnetic resonance data by an 

adapted Monte Carlo method applied to water 

resource characterization. Journal of Applied 

Geophysics, 50(1-2): 193-205. 

Johansen, H.K.. (1979): Fast Hankel transform. 

Geophys Prosp, 49(10): 1754-1759. 

Keating, K., R.A. Knight. (2008): laboratory study 

of the effect of magnetite on NMR relaxation 

rates. Journal of Applied Geophysics, 66(3-4): 

188-196. 

Nabighian, M.N., M.L. OristaglioS. (1984): On the 

approximation of finite loop sources by twodimensional 

line sources. GEOPHYSICS, 49(7): 

1027-1029. 



24

Signal Processing 



25

Optimized Wiener filtering with the Numis Poly system 

Optimized Wiener filtering with the Numis Poly system 

Esben Dalgaard, Esben Auken and Jakob Juul Larsen 

Department of Geoscience, Aarhus University, Aarhus, Denmark. 

esben.dalgaard@geo.au.dk 

Some of the major noise contaminators we 

observe in MRS data are power line harmonics 

and spikes. For a more efficient noise 

cancelling multichannel systems have been 

developed (Walsh, 2008). With regards to the 

powerline harmonics we will show a study on 

how to optimize the estimation of the transfer 

function between reference and primary 

receivers in the Numis Poly system. We will 

show how an automatic detection of spikes 

will improve and ease the signal processing. 

In the Numis Poly system a noise record is 

obtained right before the signal section, this is 

done to estimate the transfer function. This 

transfer function can be estimated with 

different filtering approaches e.g. adaptive 

filtering, Wiener filtering in both time and 

frequency domain. We have observed jitter and 

small offsets between receivers in sampling 

frequency, which lead to imprecise 

calculations of the transfer function and 

inefficient noise cancelling. We will 

demonstrate how much these hardware 

limitations will affect the noise cancelling. 

To overcome the issues with jitter and different 

sampling frequencies we explore alternative 

ways of estimating the transfer function. By 

estimating the transfer function from the signal 

record itself, the jitter offset is fixed between 

receivers, thus the filter is tuned in to these 

offsets, and no error will be induced. We 

compare transfer functions obtained from the 

noise records with transfer functions obtained 

from the signal record itself. A drawback of 

estimating the filter in the signal section is the 

risk of cancelling pure MRS in the processing 

(Dalgaard et al.). We show that in the design of 

the filter, it is possible to avoid cancelling the 

signal while estimating the filter directly on the 

signal part. 

The presence of spikes of different origins in 

MRS signal records will distort noise 

cancelling of the powerline harmonics. The 

spikes in the signals from both the primary and 

reference receivers must therefore be removed 

in advance for further noise cancelling. The 

spikes will contaminate only a part of the 

signal section, leaving a major part of the 

section uncontaminated, and thus deleting 

entire sections is not necessary. Instead a local 

detection and removal of spikes are more 

appropriate. Due to the huge data amount, a 

spike detection performed manually is very 

time consuming and an automatic spike 

detection would be preferable. 

Inspired by the work of Mukhopadhyay and 

Ray (1998) we have implemented a spike 

detection algorithm based on the nonlinear 

energy operator. An ensemble based threshold 

is used with the threshold determined by the 

median absolute deviation (MAD) (Hoaglin et 

al., 2000). We will present an efficient and 

simple procedure for automatic spike 

detection. 

Key words: magnetic resonance sounding; 

Wiener filtering; despiking; Numis Poly; 

References 

Dalgaard, E., Larsen, J.J., Auken, E. (submitted 

2012): Adaptive noise cancelling of 

multichannel magnetic resonance sounding 

signals: Geophysical Journal International. 

(submitted) 

Hoaglin, D. C., Mosteller, F., and Tukey, J. W., 

2000, Understanding robust and exploratory data 

analysis: Wiley classics library, 447. 

Mukhopadhyay, S. and Ray, G. C., 1998, A new 

interpretation of nonlinear energy operator and 

its efficacy in spike detection: IEEE Transactions 

on Biomedical Engineering, 45, 180-187. 

Walsh, D. O., 2008, Multi-channel surface NMR 

instrumentation and software for 1D/2D 

groundwater investigations: Journal of Applied 

Geophysics, 66, 140-150. 



26

Model-based cancelling of powerline harmonics in multichannel MRS recordings 

Model-based cancelling of powerline harmonics in multichannel MRS 

recordings 

Jakob Juul Larsen (1) , Esben Dalgaard (2) , Esben Auken (2) 

(1) Aarhus School of Engineering, Aarhus University, Denmark 

(2) Department of Geoscience, Aarhus University, Denmark 

jjl@iha.dk 

It is well known in the MRS community that 

MRS signals recorded in the vicinity of manmade 

installations are often heavily 

contaminated by noise. Before a useful MRS 

signal can be extracted from the measured data 

an efficient noise cancelling must be 

performed. The two most important noise 

sources are harmonics of the fundamental 

powerline frequency and spikes from electrical 

discharges. In multichannel MRS systems one 

or several reference loops are used to record 

the local noise environment simultaneously 

with the MRS signal in the primary channel. 

By appropriately filtering of the reference 

channels the noise can be subtracted from the 

primary loop record. However, a necessary 

condition for this procedure to be efficient, is 

that the same filter is optimum for all noise 

sources. In practice, we have found that this 

condition is not fulfilled e.g. a filter that 

cancels powerline harmonics does not 

necessarily cancel spikes. In this paper we 

suggest to remedy to this problem by using a 

more elaborate signal processing scheme 

where prior knowledge of the noise is used as 

previously suggested for single channel MRS 

by Legchenko and Valla (2003). The signal in 

the primary coil P(t) can be modelled as 

In the above equation FID(t) represents the 

free-induction decay signal of the sub-surface 

protons. The powerline harmonics are 

modelled as 

Where the summation is over all excited 

harmonics. The temporally short spikes are 

described by spikes(t) and w(t) represents all 

other noise contributions. This separation of 

the recorded signal into powerline-related 

components and other components have 

previously been employed for other 

geophysical methods, see e.g. Butler and 

Russell (2003). The fundamental frequency of 

the powerline is not fixed but varies on a 

timescale of typically a few seconds. f0 must 

therefore be treated as a parameter to be 

determined by fitting In this work f0 is 

assumed constant within each measurent of a 

few 100 ms duration. The values of f0 and the 

Aq and �q coefficients can be efficiently found 

with standard fitting methods. Once the model 

parameters have been determined, xh(t) is 

subtracted from P(t) hereby removing the 

powerline harmonics. Similarly, a model of the 

powerline harmonics is independently 

constructed and subtracted for each reference 

channel. 

Experiments with this model-based cancelling 

of powerline harmonics with data recorded 

with a Numis Poly have proven very effective 

with noise cancelling on par with or exceeding 

standard filtering methods. In particular, the 

method circumvents problems with jitter and 

uneven sampling frequencies between 

channels. 

Subsequent to model-based cancelling of the 

powerline harmonics the standard methods of 

multichannel noise cancelling can be applied to 

reduce the influence of other noise sources. 

References 

Butler, K.E. and Russell, R.D. (2003) Cancellation 

of multiple harmonic noise series in geophysical 

records. Geophysics 68, 1083-1090. 

Legchenko, A. and Valla, P. (2003) Removal of 

power-line harmonics from proton magnetic 

resonance sounding measurements. Journal of 

Applied Geophysics, 53, 103-120. 



27

Joint use of adaptive notch filter and empirical mode decomposition for noise cancellation 

applied to MRS 

Joint use of adaptive notch filter and empirical mode decomposition for 

noise cancellation applied to MRS 

Tian Baofeng, Lin Tingting, Yi xiaofeng, Jiang Chuandong, Lin Jun 

College of instrumentation and electrical engineering, JiLin University,Changchun,130061,China 

ttlin@jlu.edu.cn; tianbf@jlu.edu.cn 

Magnetic resonance sounding (MRS) as a kind 

of direct groundwater detection method has 

widespread application in hydrogeological 

investigation. However, the application of 

instrument has been limited by the 

susceptibility to ambient and electromagnetic 

noise. Statistical stacking and wavelet 

transform methods have the advantages for 

decreasing and removing spike noise and 

random noise. Whereas, it is still difficult to 

achieve signal-noise separation well in the 

presence of strong electromagnetic noise. 

Notch filtering is the most common method to 

reduce 50Hz or 60Hz power transmission 

harmonics for FID signal collected by early 

version of NMR instrument, but signals can be 

distorted when the Larmor frequency is close 

to a multiple of fundamental frequency. The 

United States and France have successively 

developed full-wave data acquisition NMR 

systems, which could mitigate noise based on 

adaptive noise cancellation principleby using 

referencecoils. The prerequisite for the 

application of this method depends on the fact 

that the noise of reference channel(s) has the 

best correlation with the MRS-signal detection 

channel. Sometimes, the de-noising effect is 

not ideal due to the complexity and variability 

of the environmental noise and inhomogeneous 

of the spatial distribution. 

Thus, in the present article, we propose a new 

method for signal-to-noise separation based on 

adaptive notch filter (ANF) and empirical 

mode decomposition (EMD). This method 

aims at processing the whole wave MRS signal 

with no requirement for reference coils. ANF 

has the advantages of easy to control 

bandwidth, and the bandwidth depends on the 

size of the adaptive step length parameter 

mainly. T2 is between in 30 ~ 1000 ms which 

is MRS signal transverse relaxation time, and 

its band range of frequency spectrum is 

limited. Based on this characteristic, the 

method in this paper realize the separation of 

signal and noise preliminarily through 

controlling the step length parameters of ANF 

effectively to process MRS signal with Larmor 

frequency as the center frequency. 

However, the MRS signal separated from ANF 

still contains trace of noise by the influence of 

ANF bandwidth. EMD is the most effective 

means of the extraction signal trend as a new 

type of adaptive signal time domain and 

frequency domain processing method. This 

method can divide the signal into several 

intrinsic mode function (IMF) according to the 

input signal characteristic in case of absence of 

prior knowledge. The decomposition 

remainder can represent the trend of the signal. 

Extracting envelope from the separated MRS 

signal using Hilbert transform, and extracting 

the attenuation curve using EMD denoise 

method. The results of numerical simulation 

suggest that, the performance of combining 

ANF and EMD is more effective than using 

ANF alone. The average signal-to-noise ratio 

can improve more than 12 dB, the mean error 

of the extracted initial amplitude E0 and 

relaxation time T2 is less than 5% and 10% 

respectively. It has also proved the 

effectiveness of the proposed method through 

processing the measurement data. Finally, we 

present the results of field data to substantiate 

the effectiveness of the proposed method. 

References 

Cai HanPeng, He ZhenHua, Huang DeJi. Seismic 

data denoising based on mixed time-frequency 

methods. Applied Geophysics, 2011,8(4):319- 

327. 

Haykin, S. (1996): Adaptive Filter Theory. Prentice 

Hall, Upper Saddle River, New Jersey. 

Jiang, C.D., Lin, J., Duan, Q.M., et al. (2011): 

Statistical stacking and adaptive notch filter to 

remove high-level electromagnetic noise from 

MRS measurements, Nuar Surface Geophysics, 

9:459-468. 

Legchenko, A., Valla, P. (2003): Removal of 

power-line harmonics from proton magnetic 

resonance measurements. Journal of Applied 

Geophysics 53, 103–120. 

Walsh, D.O. (2008): Multi-channel surface NMR 


groundwater investigations. Journal of Applied 

Geophysics, 66(3-4):140-150. 



28

Higher-Order Statistical Signal Processing for Surface-NMR Electronic Instruments 

Higher-Order Statistical Signal Processing for Surface-NMR Electronic 

Instruments 

Rafik Soltani, Lizhi Xiao 

State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China 

rafiksoltani2008@gmail.com 

In so many practical cases, the surface-NMR 

measurements may feature very low signal-tonoise 

ratios (SNR's). The SNR's can be low in 

cases of low free-water content, relatively deep 

groundwater, low intensities of the Earth’s 

magnetic field, conductive subsurface, or 

presence of field noises such as RFI (radiofrequency 

interferences). Therefore, it is very 

important to use robust signal processing 

software to improve the recovery of the very 

weak underlying FID signals from surface- 

NMR measurements. We propose a cumulantbased 

processing scheme for the extraction of 

FID signals from MRS data. Cumulants are 

higher-order statistics (HOS) that are wellknown 

as automatic enhancers of SNR's. That 

is, by processing MRS data into the domains of 

their cumulants, the robustness to additive 

noise can be increased. The following signal 

processing algorithms will be presented. 

Algorithm 1: Cumulant-based Mono- 

Exponential FID Estimator 

We present a fourth-order cumulant-based 

estimator for the extraction of monoexponential 

FID signals from MRS data. We 

demonstrate and illustrate the greater 

robustness to additive noise of this estimator 

over the currently and mostly used NLS 

estimators. That is, such a new estimator 

improves the extraction of MRS curves. 

Algorithm 2: Cumulant-based Multi- 

Exponential FID Estimator 

This estimator is an extension of the previous 

one from the mono-exponential to the multiexponential 

FID. It is also based on fourthorder 

cumulants. The robustness to additive 

noise of this estimator will be illustrated via 

examples. 

Algorithm 3: Adaptive Cumulant-based 

Canceler of RFI from Surface-NMR Data 

We present a fourth-order cumulant-based RFI 

canceler for multichannel surface-NMR 

instruments. This adaptive canceler can be 

viewed as an extension, from second-order to 

fourth-order statistics, of the classic adaptive 

LMS canceler. Thus, it helps to improve 

robustness to RFI in MRS data. We illustrate 

the performance of this canceler via examples. 

Algorithm 4: Adaptive ICA-based Canceler 

of RFI from Surface-NMR Data 

ICA (independent component analysis) is a 

HOS-based computational technique for 

separation of linear mixtures of statistically 

independent signals. We present an adaptive 

ICA-based RFI canceler for multichannel 

surface-NMR instruments. This canceler 

adaptively performs higher-order decorrelation 

between the canceler output signal and its 

reference input signal. That is, it can be viewed 

as an extension, from second-order to higherorder 

statistics, of the classic adaptive LMS 

canceler. Thus, it helps to further improve the 

robustness to RFI in surface-NMR data. The 

performance of this canceler will be illustrated 

through examples. 

Conclusions 

It is possible to develop complete cumulantbased 

processing software for surface-NMR 

instruments. Such software performs both the 

adaptive cancelations of eventual RFI as well 

as mono-/multi-exponential fitting. The main 

feature of such processing software is its 

improved robustness to noise by comparison to 

the currently used MLS cancelers and NLS 

estimators. The processing scheme presented 

herein is being described in details and 

illustrated by a variety of examples in a new 

book by the same authors of this abstract. Such 

a book is actually entitled as “Higher-Order 

Statistical Signal Processing for Surface 

Nuclear Magnetic Resonance Instruments – A 

Noninvasive and Direct Electronic Technology 

for Hydrogeophysics and Hydrogeology”. 

Acknowledgments: We sincerely thank all the 

people, for their good wills, to providing us 

MRS datasets and any useful information, 

either directly or indirectly. 



29

Identification and elimination of spiky noise features in MRS data 

Identification and elimination of spiky noise features in MRS data 

Stephan Costabel 1 and Mike Müller-Petke 2 

1 Federal Institute for Geosciences and Natural Resources, Berlin 

2 Leibniz Institute for Applied Geophysics, Hannover 

stephan.costabel@bgr.de 

Since time series in MRS can be recorded by 

multiple detection channels simultaneously, 

the cancellation of harmonic noise by using 

additional noise reference loops has become 

possible (Walsh, 2008). This opportunity has 

greatly extended the applicability for MRS: 

Recent case studies show that successful MRS 

measurements can be conducted with quite 

good quality even near housing or power 

lines. However, if the noise consists of 

randomly interfering signals with short length 

(some milliseconds) and high amplitudes (up 

to a view microVolt), e.g. in the vicinity of 

radio masts or electric fences, MRS 

measurements persist being very difficult. 

If spiky noise features appear in MRS data, the 

remote reference technique fails, because the 

calculation of stable transfer functions between 

the MRS signal loop and the noise reference 

loops is not possible. A conventional method 

to avoid spiky noise is to define a threshold 

during the measurement to refuse time series 

with extremely high voltages. However, this 

method often leads to an unacceptable long 

measurement duration for the entire sounding. 

Consequently, the prefered strategy is to accept 

all signals and to eliminate only the corrupted 

parts of the time series with adequate postprocessing 

techniques (Strehl et al., 2006). 

We tested and compared three post-processing 

methods to eliminate finite interfering signals 

from an MRS dataset, which was measured at 

the test site Fuhrberger Feld and shows heavy 

distortions with spiky noise. Using common 

processing schemes, this data can hardly be 

interpreted. In our study, we focussed, first, on 

the possibility to automate the algorithms to 

identify and eliminate the spiky noise features 

and, second, on the capability of these 

algorithms to be combined with processing 

tools for harmonic noise cancellation (HNC). 

The first method identifies and eliminates 

interfering signals in the time domain by 

searching for high voltage induction, i.e., 

spike-like pattern above a certain threshold. 

The second approach is based on the univariate 

wavelet transform (WT) of the measured time 

series. The interfering signal is identified and 

isolated in the wavelet domain and, after the 

inverse WT back into the time domain, 

subtracted from the original time series (Strehl 

et al., 2006). The third approach uses the 

multivariate WT and takes advantage of the 

multi-channel detection (Aminghafari et al., 

2006). 

It is shown that all procedures can easily be 

applied automatically, and can therefore easily 

be implemented on demand either as black box 

processes or as user controlled schemes into 

existing post-processing strategies. All 

techniques improved the signal-to-noise ratio 

(SNR) from 2 to about 5.5. Regarding the 

combination with the HNC, the univariate WT 

approach shows a serious shortcoming: After 

the application of the WT filter, the coherence 

of the noise pattern in the MRS signal to the 

remote references gets lost to some extent. 

Consequently, the SNR decreases from 5.5 to 3 

after successive application of the univariate 

WT and the HNC. This shortcoming was not 

found for the multivariate WT. Both, the 

multivariate WT approach and the time domain 

thresholding approach could finally reach an 

SNR of more than 7, when combined with 

HNC. 

References 

Aminghafari, M., Cheze, N., Poggi, J.-M. 

(2006): Multivariate denoising using 

wavelets and principal component analysis, 

Computational Statistics & Data Analysis 

50, 2381-2398. 

Strehl, S., Rommel, I., Hertrich, M. and 

Yaramanci, U. (2006): New strategies for fitting 

and filtering of MRS signals. Proceedings of 3 rd 

Magnetic Resonance Sounding International 

Workshop, Madrid-Tres Cantos, Spain. 

Walsh, D. O. (2008): Multi-channel surface NMR 






30

MRS noise investigations with focus on optimizing the measurement setup in the field 

MRS noise investigations with focus on optimizing the measurement setup 

in the field 

Stephan Costabel 1 and Mike Müller-Petke 2 




By using multi-channel MRS equipment the 

opportunity to cancel harmonic noise from 

MRS data can be taken (Walsh, 2008). In 

addition to the MRS measurement loop, one or 

more reference loops are placed in an 

appropriate distance (remote reference) to 

measure the noise simultaneously. In the postprocessing 

of the data, the electromagnetical 

(EM) transfer functions (TF) of the reference 

loop(s) to the measurement loop are calculated 

and used to predict the noise part in the MRS 

signal channel. Finally, the predicted noise 

trace is substracted from the measured signal, 

which leads to a significant cancellation of the 

harmonic noise. 

The quality of the noise cancellation technique 

using remote references depends on the setup 

of the reference loops, i.e., on the quality of the 

harmonic noise signal and on the spatial 

coherence of the noise. Often, the same loop 

layout (size and number of turns) as the 

measurement loop is preferred, which 

multiplies time and effort in the field. 

Consequently, the working progress in the 

field slows down, which is, in particular, a 

serious problem when performing 2D 

measurements. 

We have conducted systematic investigations 

to find a trade-off between minimizing time 

and effort in the field and applying the noise 

cancellation successfully. In doing so, we 

concentrate on three basic ideas. First, 

decreasing the size of the reference loop: A 

reference loop much smaller than the 

measurement loop is positioned much faster. 

The quality of the noise induction, which 

decreases with decreasing loop size, is 

maintained by a higher number of turns in the 

reference loop. This strategy can successfully 

be applied, unless the difference in loop size is 

not below approximately one tenth. In this 

case, the spatial coherence between the two 

loops gets lost. 

Second, the use of very small and handy 

reference loops (1 sq m) to measure the x and y 

components of the EM field for the TF 

calculation. Following the EM theory, the z 

component (i.e., the measurement loop) is 

completely described by a linear combination 

of the x and y components, at least, for the farfield 

condition. Consequently, measuring the x 

and y components as remote references leads 

to a successful noise cancellation. However, it 

fails if the site of investigation is located in the 

near vicinity of a potential noise source. 

Third, we investigated the spacial noise 

coherence in the presence of two potential 

noise sources. In doing so, we verified the 

necessity of using one remote reference loop 

for each noise source. Unfortunately, the 

attempt to gather the noise information from 

both sources with just one reference channel 

lead to unacceptable results. 

Optimizing the noise cancellation technique is 

an ongoing research field. Further gathering 

and exchanging the experiences in that area 

helps the MRS community to improve and 

optimize their field experiments. 

References 







31

A comparison of harmonic noise cancellation concepts 

A comparison of harmonic noise cancellation concepts 

Mike Müller-Petke 1 and Stephan Costabel 2 



mike.mueller-petke@liag-hannover.de 

Using multi-channel MRS equipment allows 

for cancelling harmonic noise from MRS data 

(Walsh, 2008). In addition to the MRS 

measurement loop, one or more reference 

loops are placed in an appropriate distance 

(remote reference) to measure the noise 

simultaneously. In the post-processing of the 

data, the electromagnetical (EM) transfer 

functions (TF) of the reference loop(s) to the 

measurement loop are calculated and used to 

predict the noise part in the MRS signal 

channel. Finally, the predicted noise trace is 

substracted from the measured signal, which 

leads to a significant cancellation of the 

harmonic noise. 

The quality of the noise cancellation (NC) 

depends on several factors that we have 

investigated. We distinguish between practical 

parameter to be optimized in the field as 

presented in Costabel and Müller-Petke (2012) 

and theoretical aspects present in the 

following. 

1. There are different approaches to 

calculate the TF. For instance Dalgaard et.al. 

(2012) investigated the differences in time 

domain using Wiener filtering compared to 

adaptive filter. We present a comparison of 

TFs in the time domain and frequency domain. 

2. The stability of both the filter (i.e. the 

stability of the inverse problem) and the 

harmonic noise over the measurement time. 

We present two different approaches in the 

frequency domain. A global approach taking 

all available measurements into account and a 

local approach calculating the TF using only 

one measurement. 

3. The complexity of harmonic noise. We 

distinguish between one source of noise with 

its higher harmonics and random distributed 

harmonics. 

4. If the harmonic noise is significantly 

changing with time it is necessary to calculate 

the TF using the measurement that contains the 

signal instead of using the pure noise record. 

We show how this influences the quality of 

NC, especially if the NMR frequency is close 

to a harmonic noise frequency. 

In conclusion we show that the local frequency 

domain approach will be appropriate for most 

practical cases. 

References 

Dalgaard, E., Auken, E. and Larsen, J. (2012). 

Noise cancelling of multichannel magnetic 

resonance sounding signals. Geophysical Journal 

International. In print. 

Costabel, S. and Müller-Petke, M. (2012). MRS 

noise investigations with focus on optimizing the 

measurement setup in the field. Proceeding of 

the 5 th international meeting on Magnetic 

Resonance. 







32

Modeling and Inversion 



33

The case for comprehensive frequency-domain inversion of surface NMR data 

The case for comprehensive frequency-domain inversion of surface NMR 

data 

Trevor Irons 1,2 , Yaoguo Li 1 , Jared D. Abraham 2 , and Jason R. McKenna 3 

1 Colorado School of Mines, 2 U.S. Army Engineer Research & Development Center 

tirons@mines.edu, ygli@mines.edu, jdabraha@usgs.gov, Jason.R.McKenna@usace.army.mil 

Surface NMR (sNMR) experiments involve 

large number of data. The data size of a FID 

survey with a coincident transmitter and 

receiver can easily exceed 100 000 samples. 

The increased adoption of Hahn-echo and 

pseudo-saturation recovery experiments 

compounds this problem due to the multiplepulse 

data. Furthermore, the use of multiplechannel 

instruments causes the data space to 

scale with the number of receiver channels 

(Dlugosch et al., 2011). Three-dimensional 

sNMR surveys using multiple pulses can easily 

involve millions of data. 

The sNMR inverse problem is ill-posed and 

suffers from low signal-to-noise; performance 

improves dramatically with the comprehensive 

inclusion of the complete dataset (Mueller- 

Petke and Yaramanci, 2010). However, since 

the computational cost of an inversion scales 

with the problem size, the large data space of 

sNMR datasets poses a challenge with this 

approach. This problem is compounded by the 

use of multiple pulses and receiver channels. 

There exists a clear need for a compressive 

inversion scheme that preserves the data 

content, but reduces the size of the data space. 

A common approach for data reduction is to 

demodulate the time-series through quadrature 

detection and then down sample. Implicit in 

this conversion is the transformation of the 

problem to the rotating frame. Off-resonance 

transmission and static magnetic field 

variations cause complicated artifacts in this 

frame (Walbrecker et al., 2011). Down 

sampling in the time-domain also removes 

signal at the same rate as the decimation. 

Alternatively, the signal can be demodulated in 

the Fourier-domain. The sNMR data is band 

limited, and only a narrow frequency band 

around the Larmor frequency contains signal. 

The rest of the data is in the null-space of the 

sNMR imaging kernel, and may be safely 

dismissed. This not only provides high levels 

of compression, typically about 25 times, but 

also improves the condition number of the 

underlying inverse problem. Most importantly, 

no signal is lost in this transformation and 

decimation. 

There are several other advantages. The sNMR 

data are typically subjected to Fourier-domain 

filters with some amount of ripple and/or phase 

distortion. These effects can easily be 

integrated into frequency-domain forward 

modeled data. Off-resonance transmission 

effects are more straightforward. 

Under this framework, it is also easy to 

incorporate dephasing dynamics of spins under 

the fast-diffusion approximation. This dephasing 

introduces non-exponential decay that 

cannot be fit with single or multiple 

exponential terms, but can easily be 

incorporated in the frequency-domain imaging 

kernel. This feature allows inversions to 

achieve much lower data misfit under 

appropriate circumstances, and can be critical. 

In this paper, a constrained 1-D frequencydomain 

sNMR inversion using the 

comprehensive approach in the frequency 

domain is presented. A logarithmic barrier 

method combined with Tikhonov 

regularisation approach is adopted. An L-curve 

criterion is used to determine the optimal 

regularization parameter. Application to two 

field data sets which exhibit non-exponential 

decay acquired at different locations has 

produced improved results over conventional 

methods. 

References 

Dlugosch, R., M. Müeller-Petke, T. Günther, S. 

Costabel, and U. Yaramanci, 2011, Assessment 

of the potential of a new generation of surface 

nuclear magnetic resonance instruments: Near 

Surface Geophysics, 9, 169–178. 

Müeller-Petke, M., and U. Yaramanci, 2010, Qt 

inversion — comprehensive use of the complete 

surface NMR data set: Geophysics, 75, WA199– 

WA209. 

Walbrecker, J. O., M. Hertrich, and A. G. Green, 

2011, Off-resonance effects in surface nuclear 

magnetic resonance: Geophysics, 76, G1–12. 



34

Inversion of T1 relaxation times based on pcPSR measurements - Synthetic examples 

Inversion of T1 relaxation times based on pcPSR measurements - Synthetic 

examples 

Mike Müller-Petke 1 and Jan O. Walbrecker 2 

1 Leibniz Institute for Applied Geophysics, Hannover, Germany 

2 Stanford University, Department of Geophysics, Stanford, USA 

mike.mueller-petke@liag-hannover.de 

The ability of estimating hydraulic 

conductivties K from Surface Nuclear 

Magnetic Resonance (SNMR) measurements is 

one of the main reasons of the increasing 

interest in this technique in the field of 

hydrogeophysics. The key of estimating K is 

the sensitivity of NMR relaxation times to pore 

sizes. However, it is well known, both in field 

and laboratory applications, that the relaxation 

time T2* obtained from the free induction 

decay (FID) is controlled not only by pore 

sizes, but also by magnetic inhomogeneities, 

which do not affect T1 relaxation. 

Legchenko et al. (2004) published a T1 

measurement and inversion scheme for SNMR. 

The scheme, named pseudosaturation recovery 

(PSR), consists of a double-pulse experiment, 

i.e. two pulses separated by a time tau. In PSR 

the FID recorded after the second pulse is then 

used to invert for the T1 relaxation time. The 

PSR scheme has been widely applied since its 

introduction, typically using data from a single 

double-pulse experiment (i.e., tau). 

Walbrecker et al. (2011a) showed that such 

double-pulse experiments are highly 

influenced by off-resonance effects that are 

inevitable in SNMR. In addition, Walbrecker 

et. al. (2011b) showed that PSR is influenced 

by the T2* relaxation, which has not been 

taken into account during the inversion of PSR 

data. The authors proposed a new 

measurement sequence using a phase-cycled 

pseudosaturation recovery (pcPSR) that 

minimizes the influence of both, off-resonance 

and T2*, effects. 

Based on Walbrecker et al. (2011) we 

developed an inversion scheme to estimate the 

distribution of T1 in the subsurface. Since the 

SNMR kernel function becomes a function of 

the T1 distribution in the subsurface, the 

inverse problem becomes higly non-linear and 

time consuming to solve. Our inversion 

approach is based on the QT inversion concept 

(Müller-Petke & Yaramanci, 2010), extended 

to take account for the T1 influence on the 

kernel function. In addition to the details of our 

inversion approach we present a synthetic 

example to address the following practical 

issues that are important for SNMR T1 

surveys: 

1. How many soundings (i.e., tau’s) are 

required for a T1 inversion? 

2. How sensitive is SNMR to changes in 

the T1 parameter (in the presence of 

noise)? 

3. How far off is the old inversion 

scheme based on PSR data? 

References 

Legchenko, A., Baltassat, J.-M., Bobachev, A., 

Martin, C., Robain, H. & Vouillamoz, J.-M. 

(2004): Magnetic Resonance Sounding Applied 

to Aquifer Characterization. Ground Water, 

Blackwell Publishing Ltd, 42 (3), 363-373. 

Mueller-Petke, M. & Yaramanci, U. (2010): QT 

inversion --- Comprehensive use of the complete 

surface NMR data set. Geophysics, SEG, 75 (4), 

WA199-WA209. 

Walbrecker, J. O., Hertrich, M. & Green, A. G. 

(2011a): Off-resonance effects in surface nuclear 

magnetic resonance. Geophysics, SEG, 76 (2), 

G1-G12. 

Walbrecker, J. O., Hertrich, M., Lehmann-Horn, J. 

A. & Green, A. G. (2011b): Estimating the 

longitudinal relaxation time T1 in surface NMR. 

Geophysics, SEG, 76 (2), F111-F122. 



35

Inversion of surface-NMR T1 data: results from two field sites with reference to borehole 

logging 36 

Inversion of surface-NMR T1 data: results from two field sites with 

reference to borehole logging 

Jan O. Walbrecker 1* , Mike Müller-Petke 2 , Rosemary Knight 1 , Ugur Yaramanci 2 



* jan.walbrecker@stanford.edu 

For any study addressing the quantity of 

producible water in groundwater aquifers the 

hydraulic conductivity is a crucial piece of 

information. Because hydraulic conductivity 

can be inferred through empirical relations 

from the NMR relaxation times, they are 

important measurement parameters in many 

surface-NMR applications. Unfortunately, the 

relaxation time most readily available from 

surface-NMR measurements, the effective 

transverse relaxation time T2 * , is strongly 

affected by the presence of magnetic species. 

In many realistic situations their influence is so 

dominant that T2 * becomes an unreliable 

estimator for hydraulic conductivity 

(Grunewald and Knight, 2011). Therefore, 

surface-NMR studies aimed at hydraulic 

properties often resort to measuring the 

longitudinal relaxation time T1 (Legchenko et 

al., 2004), which is less affected by magnetic 

field inhomogeneities. Recent theoretical 

developments have demonstrated how robust 

surface-NMR T1 data can be acquired by 

employing an optimized acquisition technique 

termed phase-cycled pseudosaturation 

recovery (pcPSR; Walbrecker et al., 2011). In 

this study we complete these recent advances, 

which focused on data acquisition, by 

developing an inversion that estimates the 

depth distribution of T1 based on pcPSR data. 

We apply our new inversion scheme in two 

field studies and resolve how the T1 relaxation 

time varies with depth. In both cases we have 

access to borehole-NMR data as references. At 

site 1, Schillerslage (Germany), we acquired 

pcPSR surface-NMR T1 data at 4 delay times 

(50, 100, 300, and 700 ms) using a circular 

loop configuration (50 m diameter). Our 

inversion result indicates that T1 increases 

continuously across the first aquifer, from 400 

ms to 700 ms at 15 m depth (less variation in 

T2 * data), and remains constant across the 

second aquifer where T2 * decreases. Both the 

gradual increase of T1 with depth, as well as 

the increased T1 for the second aquifer is 

confirmed by the borehole data. At site 2 close 

to Lexington (Nebraska, USA), we acquired 

pcPSR T1 data at 4 delay times (133, 208, 506, 

and 789 ms) in a circular figure-eight setup 

(41 m diameter per circle). In this case, T1 

increases from about 260 ms close to the 

surface to 450 ms at 16 m depth, and then 

decreases to about 150 ms towards the 

penetration limit for our setup (~40 m). As for 

the previous survey, the relative trend of our 

surface-NMR T1 result is consistent with our 

borehole measurements. The borehole data 

show more details in the T1 profile, and tend 

towards lower absolute T1 values. These 

differences between the two methods we 

attribute to (1) the frequency dependence of 

relaxation and magnetic susceptibility effects 

(surface NMR operates at 2 kHz, borehole 

NMR at ~250 kHz to 1 MHz), and (2) the fact 

that surface NMR samples a much larger 

volume than the borehole tool, smoothing out 

small-scale details visible in the borehole data. 

We implemented our inversion of pcPSR T1 

data in MRSmatlab, which is freely available 

to the surface-NMR community. 

Acknowledgments 

This research was supported by funding to R. 

Knight and Y. Song from the Hydrology Program 

and the GOALI (Grant Opportunities for Academic 

Liaison with Industry) Program of the U.S. 

National Science Foundation (Award no. 0911234). 

References 

Grunewald, E., Knight, R. (2011): The effect of 

pore size and magnetic susceptibility on the 

surface NMR relaxation parameter T2 * . Near 

Surface Geophysics, 9, 169-178. 

Legchenko, A., Baltassat, J.M., Bobachev, A., 

Martin, C., Robain, H., Vouillamoz, J.M. (2004): 

Magnetic resonance sounding applied to aquifer 

characterization. Ground Water, 42, 363-373. 

Walbrecker, J.O., Hertrich, M., Lehmann-Horn, 

J.A., Green, A.G. (2011): Estimating the 


Geophysics, 76, F111-F122. 


Hannover, Germany, 25 – 27 September 2012

Earth's magnetic field and MRS phase shift 37 

Earth's magnetic field and MRS phase shift 

Legchenko 1* A., M. Descloitres 1 , K. Chalikakis 2 , M. Boucher 1 , G. Favreau 3 

1 IRD / LTHE, Grenoble, France; 2 LHA, Avignon, France; 3 IRD / HSM, Montpellier, France. 

anatoli.legtchenko@ird.fr 

At the early stage of development of the 

magnetic resonance sounding method (MRS) 

only the amplitude of MRS signal was used for 

inversion (Legchenko and Shushakov, 1998). 

However it has been shown that use of both the 

amplitude and the phase for inversion allows 

better resolution (Weichman et al., 2002). 

Correct modeling of the phase shift is also 

important for inversion of resistivity in MRS 

(Braun and Yaramanci, 2008). 

It is known that the phase of the magnetic 

resonance signal mainly depends on 1) the 

electrical conductivity of the subsurface 

(Trushkin et al., 1995); and 2) the frequency 

offset between the Larmor frequency and the 

frequency of the transmitted EM field 

(Mansfield et al., 1979). While the subsurface 

cause only positive phase shift, the frequency 

offset may cause both positive and negative 

shifts (Legchenko, 2004). 

Usually, the Earth's magnetic field is 

considered as constant. In practice however, 

the frequency offset may be often non-zero 

because of 1) MRS system may be tuned with 

some frequency offset; 2) the geomagnetic 

field may vary in time; 3) the geomagnetic 

field may vary with depth. 

We developed and tested a procedure that 

allows modeling of the phase shift taking into 

account the frequency offset. For that we use 

the MRS signal measured for each pulse 

moment but also we check time variations of 

the geomagnetic field either using a proton 

magnetometer or performing time lapse 

measurements of the MRS signal for a fixed 

pulse moment. Than, depth variations of the 

geomagnetic field are derived from the 

inversion of measured frequency of the MRS 

signal. These data allow computing the phase 

shift for each synthetic layer. Time varying 

geomagnetic field cause phase variations for 

all the layers: for each pulse moment the 

geomagnetic field corresponds to measured 

geomagnetic field in corresponding period of 

time. 

We demonstrate efficiency of this approach 

using MRS and TDEM data obtained in the 

Lake Chad area (Western Africa). In the 

investigated area the aquifer is composed of 

layered alluvial deposits with typical electrical 

resistivity of around 20-30 �m. Modeling of 

the phase shift taking into account TDEM data 

and using a standard procedure (Valla and 

Legchenko, 2002) did not allow us to 

reproduce measured phase with the accuracy 

sufficient for inversion of complex signals. 

Hence, only amplitude inversion was possible. 

However, when variations of the Earth's 

magnetic field were taken into account we 

were able to apply inversion of complex 

signals and consequently resolution of the 

survey was significantly improved for deeper 

part of the aquifer. We also observed much 

better correspondence between MRS and 

TDEM results. 

References 

Braun, M., and U. Yaramanci (2008): Inversion of 

resistivity in Magnetic Resonance Sounding. 

Journal of Applied Geophysics, 66, 151-164. 

Legchenko, A.V., and O.A. Shushakov (1998): 

Inversion of surface NMR data. Geophysics, 63, 

75-84. 

Legchenko, A. (2004): Magnetic Resonance 

Sounding: Enhanced Modeling of a Phase Shift. 

Applied Magnetic Resonance, 25, 621-636. 

Mansfield, P., A.A. Maudsley, P.G. Morris and I.L. 

Pykett (1979): Selective pulses in NMR 

imaging: reply to criticism. Journal of Magnetic 

Resonance, 33, 261—274. 

Trushkin, D.V., O.A. Shushakov and A.V. 

Legchenko (1995): Surface NMR applied to an 

electroconductive medium. Geophysical 

Prospecting, 43, 623-633. 

Valla, P., and A. Legchenko (2002): Onedimentional 

modelling for proton magnetic 

resonance sounding measurements over an 

electrically conductive medium. Journal of 


Weichman, P.B., D.R. Lun, M.H. Ritzwoller and 

E.M. Lavely (2002): Study of surface nuclear 

magnetic resonance inverse problems. Journal of 

Applied Geophysics, 50, 131—147. 



Bloch-Siegert effect in MRS 

Oleg A. Shushakov 1, 2 , Alexander G. Maryasov 1 

1) Institute of Chemical Kinetics and Combustion SB RAS, Novosibirsk, Russia 

2) Novosibirsk State University, Novosibirsk, Russia 

shushako@kinetics.nsc.ru 

The special case of a weak field rotating 

around the strong field is usually used in the 

magnetic resonance applications. Bloch and 

Siegert studied more general case of the 

magnetic resonance with elliptic polarization 

of the radiofrequency field in particular the 

commonly used case of simple linear 

oscillation. The Earth’s magnetic field is of the 

order of 5∙10 -5 T. The RF-field produced by the 

surface antenna is linearly polarized and can be 

compatible with the geomagnetic field. The 

using of RF pulses at Larmor frequency leads 

to appearance of the mean resonance offset in 

rotating frame, 

2 2 

�1 sin �� 8�1cos�� 1��. (1) 

16�0 � 3�0 

� 

Here � is angle between static Earth B0 and 

linearly polarized B1 RF magnetic fields in lab 

frame, �0=�B0 is Larmor frequency, �1=�B is 

Rabi frequency, � is gyromagnetic ratio for 

protons. The equation (1) gives the value for 

Bloch-Siegert shift with one order higher 

accuracy than usual. 

The magnetic-resonance sounding (MRS) has 

been measured using 100m diameter antenna. 

The Ob reservoir near Novosibirsk has been 

chosen to make measurements (figure 1). 

Fig. 1 A scheme of MRS experiment to study the 

Bloch-Siegert effect with one order higher accuracy 

of subice water at the Ob reservoir near 

Novosibirsk. 

Fig. 2 exemplifies a good agreement between 

measured and calculated data taking into 

Bloch-Siegert effect in MRS 38 

account the Bloch-Siegert and the next-order 

effects. 

Fig. 2. A comparison of MRS amplitude vs pulse 

moment (amplitude times duration) at 40 and 80ms 

pulse durations calculated and measured with the 

signal calculated without the Bloch-Siegert effect. 

Legchenko et al. explain similar data and a 

significant discrepancy between measured and 

calculated data without considering of the 

Bloch-Siegert effect by existence of aquifer 

under the floor of Ob reservoir at depth 50 to 

100 m with 5% of water content. Nevertheless, 

such an interpretation is incorrect. MRS 

relaxation time T2 * of subice Ob-lake bulk 

water measured is 1s, whereas relaxation time 

T2 * of aquifer groundwater in pores is usually 

100-200ms, thus is 5-10 times shorter. 

Moreover, there is no borehole drilling data or 

some other information, confirming the 50- 

100m aquifer existence. 

References 

Bloch F., Siegert A., (1940) Magnetic resonance for 

nonrotating fields. Phys. Rev. v. 57, p. 522. 

Legchenko A., Baltassat J.-M., Bobachev A., 

Martin C., Robain H., and Vouillamoz J.-M. 

(2004) Magnetic resonance sounding applied to 

aquifer characterization. Ground Water, v. 42, 

No 3, p. 363. 



2D Cell Inversion for Magnetic Resonance Tomography using JLMRS-Array Instrument 39 

2D Cell Inversion for Magnetic Resonance Tomography using JLMRS- 

Array Instrument 

Jiang Chuandong, Duan Qingming, Yi Xiaofeng, Lin Jun 


lin_jun@jlu.edu.cn; willianjcd@yahoo.com.cn 

Introduction 

In most geophyscial applications, magnetic 

resonance sounding (MRS) is based on a single 

coincident transmitter and receiver loop for 

investigating 1D groundwater verically below 

the loop. By using multiple-offset concident 

loop as well as separated loop configurations , 

magnetic reosnance tomography (MRT) 

technology is developed for permitting full 2D 

water reconstruction. However, compared to 

1D water inverted sechmes (smooth, block, TS 

and QT), which are sounding and effective, , 

2D inversion strategies demands for further 

development. 

Array-MRT 

Array-MRT measurement is consists of a large 

single turn loop energizes a pulse of alternating 

current for exciting the deeper and farer 

hydrogen proton, and several small multiturn 

loops laid out on a profile for receiving MRT 

signals, simultaneously. Increasing of loop 

turns can improve the amplitude of signal. 

Thus, loop array composed by these multiturn 

loops will significantly improve the sensibility 

of non-stratified groundwater in 2D and 3D. 

Simulation results indicate the sensibility of 

Array-MRT is superior to multiple-offset 

concident loop or separate loops. 

Array-MRT measurement is performed using 

JLMRS-Array instrument developed by Jilin 

University (China). The instrument has one 

transimitter unit which produces maximum AC 

current pulses in excess of 450 A across the 

transimitter loop of 100 m, and 6~10 receiver 

units (capable of extending more units), 

allowing it to simultaneously receiving MRT 

signals on all the multiturn loops of 10 m~ 25 

m. The analog amplifier circuitry has a gain of 

60 dB ~ 120 dB and a bandwidth of 48 Hz ~ 

122 Hz. Through the field testing, the receiver 

short-circuit input noise is 1 nV/Hz 1/2 , and the 

dead-time is about 17 ms. 

Cell inversion 

Array-MRT data are inversed by a new 

inversion scheme, cell inversion. A water cell 

is defined as a certain area contain the specific 

water contain and relaxation time T2. Similar 

with block inversion, the location and 

boundary of cell is not fixed, however, cells 

permits coincide with each other, which blocks 

cannot. In the coincidence area, water contents 

are the sum over all cells, but T2s are 

independent from each other. According to 

area equivalent, water cells can be converted to 

subdivision grids of groundwater distribution 

for forward calculation and inversion. 

Cell inversion uses all MRT records in time 

domain of receiver loop array to seek an 

optimal water content and T2 model. The 

algorithm of cell inversion is finished by 

combined with genetic algorithm (GA) and 

nonlinear programming (NP). Simulation 

results show the new inversion scheme can 

separate multiple water cells with multi-T2 in 

2D. 

Field example 

A field measurement has been carried out 

using JLMRS-Array instrument in Shaoguo 

town, China. The results verify the 2D 

groundwater distribution characteristics, and 

compared with the 1D results of smooth, block 

and QT inversion, as well as borehole data. 

Conclusion 

Array-MRT measurement using JLMRS-Array 

instrument improves the efficiency and 

sensibility of detection 2D non-stratified 

groundwater. Data inversed by Cell inversion 

can reconstruction of water content and multi- 

T2 in 2D, simultaneously. 

References 

Hertrich, M., Braun M., Yaramanci U. (2009): 

High-resolution surface NMR tomography of 

shallow aquifers based on multioffset 

measurements. Geophysics, 74(6): 47-59. 

Mueller-Petke, M., Yaramanci U. (2010): QT 

inversion – Comprehensive use of the complete 

surface NMR data set. Geophysics, 75(4):199- 

209. 

Legchenko, A., Clement R., Garambois, S., (2011): 

Investigating water distribution in the Luitel 

Lake peat bog using MRS, ERT and GPR. Near 

Surface Geophysics, 9: 201-209 



2D qt-inversion to investigate spatial variations of hydraulic conductivity using SNMR 40 

2D qt-inversion to investigate spatial variations of hydraulic conductivity 

using SNMR 

Raphael Dlugosch 1 , Thomas Günther, Mike Müller-Petke, and Ugur Yaramanci 

Leibniz Institute for Applied Geophysics (LIAG), Hannover 

1 Raphael.Dlugosch@liag-hannover.de 

Surface-NMR is able to detect water content in 

the subsurface. Additionally, hydraulic 

conductivities can be estimated from NMR 

decay times (Legchenko et al. 2002, Dlugosch 

et al., 2011b). Both make SNMR a useful tool 

to answer hydrological questions. Most 

applications are 1D but SNMR has moved on 

to 2D targets (Hertrich et al., 2005; Hertrich et 

al., 2007) using comprehensive datasets while 

Girard et al. (2007) uses only coincident loops. 

The development of multi channel 

instrumentation made comprehensive 2D 

datasets time efficient (Dlugosch et al., 2011a). 

Current 2D inversions focus on estimating the 

water content distribution but do not invert for 

spatial information of relaxation time T2*. 

Thus, estimation of hydraulic conductivity is 

yet undone. We present the development a 

robust inversion to estimate a 2D distribution 

of T2*. Finally, this enables to image spatial 

variations in hydraulic conductivity from 

SNMR data with a high lateral resolution. 

The inversion is based on the qt-inversion 

scheme (Müller-Petke and Yaramanci, 2010). 

It exploits the full measured free induction 

decay data cube and increases both spatial 

resolution and stability of the inverse problem. 

By accounting for separate transmitter and 

receiver loops an increased lateral resolution is 

expected as shown by Hertrich et al. (2005). 

A challenging problem for a 2D inversion of 

water content and decay time is the size of the 

inverse problem both at the model and data 

domain. We use an irregular mesh and monoexponential 

decay per cell to minimize the 

number of free parameter in the model domain. 

In addition the FID data is gate integrated to 

minimize the size of the dataset (Behroozmand 

et al., 2012). We present first preliminary 

results of a synthetic dataset. 

References 

Behroozmand, A. A., Auken, E., Fiandaca, G., 

Christiansen, A. V. & Christensen, N. B. (2012): 

Efficient full decay inversion of MRS data with a 

stretched-exponential approximation of the 

distribution. Geophysical Journal International, 

Blackwell Publishing Ltd, 190 (2), 900-912. 

Dlugosch, R., Müller-Petke, M., Günther, T., 

Costabel, S. and Yaramanci, U., 2011a. Assessment 

of the Potential of a new Generation of surface 

NMR instruments, Near Surface Geophysics 9(2), 

123-134. 


Ronczka, M. and Yaramanci, U., 2011b. An 

extended model for predicting hydraulic 

conductivity from NMR measurements. – EAGE 

Near Surface 2011, 12,-14.09.2011; Leicester 

Girard, J.-F., Boucher, M., Legchenko, A. & 

Baltassat, J.-M. (2007): 2D magnetic resonance 

tomography applied to karstic conduit imaging. 

Journal of Applied Geophysics, 63 (3-4), 103-116. 

Hertrich, M., Braun, M., Yaramanci, U., 2005. 

Magnetic resonance soundings with separated 

transmitter and receiver loops, Near Surface 

Geophysics 3(3), 131-144. 

Hertrich, M., Braun, M., Günther, T., Green, A., 

Yaramanci, U., 2007. Surface Nuclear Magnetic 

Resonance Tomography, IEEE Transactions on 

Geoscience and remote sensing 45, 3752-3759. 

Legchenko, A., Baltassat, J.-M., Beauce, A., 

Bernard, J. (2002): Nuclear magnetic resonance as 

a geophysical tool for hydrogeologists. Journal of 

Applied Geophysics, 50 (1-2), 21-46. 

Müller-Petke, M., Yaramanci, U., 2010. QT 

inversion - Comprehensive use of the complete 

surface NMR data set, Geophysics 75, WA199 - 

WA209. 



Locating a karst conduit with 2D Monte Carlo inversion of magnetic resonance 

measurements 41 

Locating a karst conduit with 2D Monte Carlo inversion of magnetic 

resonance measurements 

Chevalier* A., A. Legchenko, M. Boucher 

UJF, IRD / LTHE, Grenoble, France 

Antoine.chevalier@ujf-grenoble.fr 

Assessing the ability of magnetic resonance 

measurement to reconstruct heterogeneous 2D 

and 3D water saturated formations by means of 

inversion algorithms is a recent issue for MRS 

applications (Hertrich et al. 2009; Legchenko 

et al 2011). Non-uniqueness of inversion 

results in conjunction with limited accuracy of 

measurements affected by electromagnetic 

noise may cause erroneous interpretations. The 

best way to deal with this issue is to compute a 

great number of water content distributions 

consistent with the data set, and to propose a 

probabilistic answer instead of a single 

solution using Monte Carlo approaches. 

(Mosegaard et al, 1995) 

The Poumeyssens site (southern France) was 

previously investigated with MRS (Boucher et 

al, 2006 and Girard et al, 2007). Eleven 1D 

soundings were performed with 3 turns 25×25 

m 2 coincident overlapping loops on a single 

profile crossing the conduit. Entirely mapped 

by divers, the Poumeyssens karst conduit is a 

target of choice to put 2D linear and Monte 

Carlo inversion algorithms to the test. 

Reported results, based on a strongly 

constrained linear inversion routine, show that 

the principal conduit was correctly located 

with MRS but the possibility of existence of 

other conduits in the area was not analyzed. 

We now investigate results obtained through 

less constrained 2D inversion scheme based on 

the Monte Carlo approach. 

To compute the occurrence probability of such 

a scenario, we use a Simulated Annealing 

algorithm driven by a Blocky prior idea 

(generating models using blocks of water). Its 

capability to resolve different models with 

100% water content was tested numerically 

varying the signal to noise ratio. 

The average water content computed from the 

solution collection, show that the models were 

resolved within an uncertainty of 5 to 10 m 

where the true 100 % water content is 

gradually scattered from a central maximum 

(50%) to the edge (10%). The standard 

deviation of the water content distribution is 

between 30 and 50 %. 

Analysis of the field data shows that the 

Poumeyssens conduit was correctly resolved 

with MRS using either linear or Monte Carlo 

inversion. Use of the Monte Carlo method 

allowed estimating the uncertainty in the 

conduit localization as about 5 m. In this zone, 

the MRS water content was scattered from 

50% in the center to 10% towards the edges of 

the zone. The possibility of existence of other 

conduits was estimated as highly improbable 

among the collection of well-fitting scenarios. 

To conclude, a Blocky simulated annealing 

algorithm was proved to be reliable and 

efficient approach to assess the inversion 

uncertainties on 2D targets such as karstic 

conduit. 

References 

Boucher, M., J.-F. Girard, A. Legchenko, J.-M. 

Baltassat, N. Dörfliger, et K. Chalikakis (2006): 

Using 2D inversion of magnetic resonance 

soundings to locate a water-filled karst conduit: 

Journal of Hydrology, 330(3–4). 413–421. 

Girard, J-F, M. Boucher, A. Legchenko, and J-M. 

Baltassat (2007): 2D magnetic resonance 

tomography applied to karstic conduit imaging: 


Hertrich, M., A.G. Green, M. Braun, and U. 

Yaramanci (2009): High-resolution surface 

NMR tomography of shallow aquifers based on 

multioffset measurements: Geophysics, 74, 47- 

59. 

Legchenko, A., M. Descloitres, C. Vincent, H. 

Guyard, S. Garambois, K. Chalikakis and M. 

Ezersky (2011): Three-dimensional magnetic 

resonance imaging for groundwater: New 

Journal of Physics, 13, 025022, doi: 

10.1088/1367-2630/13/2/025022. 

Mosegaard, K. and Tarantola, A. (1995): Monte 

Carlo sampling of solutions to inverse problems: 

Journal of Geophysical Research, 100(7), 431- 

447. 



A comprehensive study of the parameter determination in a joint MRS and TEM data 

analysis scheme 42 

A comprehensive study of the parameter determination in a joint MRS and 

TEM data analysis scheme 

Ahmad A. Behroozmand, Esben Dalgaard, Anders Vest Christiansen and Esben Auken 

Department of Geoscience, Aarhus University, Aarhus, Denmark. 

ahmad@geo.au.dk 

We present a comprehensive study of the 

parameter determination of magnetic 

resonance sounding (MRS) models, in a joint 

MRS and transient electromagnetic (TEM) 

data analysis scheme. We assessed model 

parameter determination by calculating the 

model parameter uncertainties, based on the aposterior 

model covariance matrix. Doing this, 

we include the full system transfer function, 

including data noise and system parameters 

which are crucial in order to get reliable 

uncertainty estimates. The analyses are 

computed for conductive layered half-spaces. 

The entire MRS data set, dependent on pulse 

moment and time gate values, together with 

TEM data, was used for all analyses and 

realistic noise levels were assigned to the data. 

The sensitivity analyses were studied for the 

determination of Water content as a key 

parameter estimated during inversion of MRS 

data. We show the results for different suites of 

(three-layer) models, in which we investigated 

the effect of resistivity, water content, 

relaxation time, loop side length, number of 

pulse moments, and measurement dead time on 

the determination of water content in a waterbearing 

layer. For all suites of models the 

effect of a top conductive and a top resistive 

layer were compared. Moreover, we analyzed 

all models for measurement dead times of both 

40 ms (typically used with Numis Poly/Plus 

equipment, IRIS Instruments) and 10 ms 

(relevant to GMR equipment, Vista Clara Inc.). 

We conclude that, in general, the resistivity 

of the water-bearing layer (layer of interest, 

LOI) does not affect the determination of water 

content in the LOI, but resistivity of the top 

layer increases depth resolution; the water 

content of the LOI does not influence its 

determination considerably in cases where the 

signal has a relatively long relaxation time in 

the LOI; determination of the water content in 

the LOI is improved by increasing the 

relaxation time of the signal in the LOI; short 

measurement dead times will improve the 

parameter determination for signals with a 

relatively short relaxation time; increasing loop 

side length and increasing the number of pulse 

moments do not necessarily improve the 

parameter determination. 

Key words: magnetic resonance sounding 

(MRS); parameter determination; sensitivity 

analysis; TEM. 

References 


Christiansen, A. V., and Christensen, N. B., 

2012, Efficient full decay inversion of MRS 

data with a stretched-exponential 

approximation of the T2* distribution: 

Geophysical Journal International, 190, 

900-912. 


and Christiansen, A. V., 2012, Improvement 

in MRS parameter estimation by joint and 

laterally constrained inversion of MRS and 

TEM data: Geophysics, 77(4), WB191- 

WB200. 

Mueller-Petke, M. and Yaramanci, U., 2008, 

Resolution studies for Magnetic Resonance 

Sounding (MRS) using the singular value 

decomposition: Journal of Applied 


Tarantola, A. and Valette, 1982, Generalized 

nonlinear inverse problems solved using a 

least squares criterion: Rewiews of 

Geophysics and Space Physics, 20, 219-232. 



Hybrid and multi-objective genetic algorithm applications in MRS data inversion 43 

Hybrid and multi-objective genetic algorithm applications in MRS data 

inversion 

Irfan Akca 1 , Thomas Günther 2 , Mike Müller-Petke 2 , Ahmet T. Basokur 1 and Ugur 

Yaramanci 2 

1 Ankara University, Faculty of Engineering, Department of Geophysical Engineering 

2 Leibniz Institute for Applied Geophysics, Stilleweg, 2, Hannover, Germany 

iakca@eng.ankara.edu.tr 

The aim of inversion algorithms is to estimate 

the parameters of a model which represents the 

subsurface within the resolution of applied 

geophysical method. The derivative based 

local optimization methods could provide fast 

and satisfactory solutions. However, the illposed 

nature of geophysical inversion leads to 

stability problems. They may suffer from the 

probability of trapping in a local minumum 

depending on the initial-guess. Genetic 

algorithms (GA) are inspired from the 

evolution of organisms that controlled by the 

environmental conditions (Holland, 1975; 

Goldberg, 1989). GAs generates a random 

initial model population and rate all models in 

the population by the help of objective 

function. Local and global optimization 

methods have their own advantages and 

disadvantages. For this reason, the sequential 

and hybrid apllications of global and local 

methods can be used to overcome the 

difficulties encountered in the individiual 

applications (Başokur et al., 2007; Akca and 

Başokur, 2010; Başokur et al., 2007; Soupios 

et al., 2011). Moreover, the hybrid algorithms 

can be applied for the joint inversion problems 

that are applied for reducing uncertainities in 

the model. Hybrid genetic algoritms give the 

ability of searching a wide solution space 

without loosing the fine tuning capability of 

the local methods while reducing the classical 

GA evolution time. 

This paper deals with the application of a 

hybrid GA (GA hybridized with least-squares) 

for the inversion of magnetic resonance 

sounding (MRS) data and a multi-objective 

GA for the joint inversion of MRS and vertical 

electrical sounding (VES) data. 

The following procedure is applied for the 

proposed hybrid genetic algorithm: An initial 

population is created within the limits of the 

search space (1); selection, cross-over and 

mutation operators proceed as in the simple 

GA (2); each model at intermediate 

generations is tried to be updated by leastsquares 

inversion (3); succesfull inversion 

candidates are replaced back into the 

population (4). The efficency of the hybrid 

scheme is tested by the use of synthetic and 

field data applications. 

Furthermore, a multi-objective GA (Deb, 

2001) is utilized for the joint inversion of MRS 

and VES data for a 1D blocky subsurface 

model. The model vectors defined for both 

methods are interconnected via the thicknesses 

(Günther and Müller-Petke, 2012). At final 

stage a Pareto-optimal set of solutions is 

obtained. 

References 

Akca, İ. and Başokur, A. T., (2010): Extraction of 

structure-based geoelectric models by hybrid 

genetic algorithms, Geophysics, 75, F15-F22. 

Başokur, A. T., Akça, İ. and Siyam, N. W. A. 

(2007): Hybrid genetic algorithms in view of the 

evolution theories with application for the 

electrical sounding method. Geophysical 

Prospecting, 55, 393–406. 

Deb, K., (2001): Multi-Objective Optimization 

using Evolutionary Algorithms, John Wiley & 

Sons, Ltd, Chichester, England. 

Goldberg, D.E. (1989): Genetic Algorithms in 

Search, Optimization, and Machine Learning. 

Addison-Wesley Publ. Co., Inc. 

Günther, T. and Müller-Petke, M. (2012): 

Hydraulic properties at the North Sea island 

Borkum derived from joint inversion of magnetic 

resonance and electrical resistivity soundings. 

Hydrol. Earth Syst. Sci. 9, 2797-2829. 

Holland, J. (1975): Adaptation in Natural and 

Artificial Systems. University of Michigan Press. 

Soupios, P., Akca, I, Mpogiatzis P., Basokur, A. T. 

and Papazachos, C., (2011):, Applications of 

hybrid genetic algorithms in seismic 

tomography, Journal of Applied Geophysics, 74, 

479-489. 



Experimental verification of a 3D model for MRS 

Legchenko 1* A., J-F. Girard 2 , S. Morlighem 3 and J-M. Baltassat 2 

1 IRD / LTHE, Grenoble, France; 2 BRGM, Orléans, France; 3 VALE, New Calédonia. 

anatoli.legtchenko@ird.fr 

It is known that only one coincident 

transmitting-receiving loop is required for the 

1D magnetic resonance sounding (MRS) 

measuring and inversion (Legchenko and 

Shushakov, 1998). The method could be 

extended to 2D (Girard et al., 2007) and 3D 

(Legchenko et al., 2011) applications and use 

of a multi-channel receiver allows a more 

sophisticated 3D implementation (Hertrich et 

al., 2009). Whatever would be the practical 

implementation of a 3D MRS survey, 

inversion is based on the forward modeling of 

the magnetic resonance response. 

Consequently, the mathematical model is a 

crucial point for the inversion. 

In the majority of reported applications the 

MRS method is used in the FID mode when 

the free induction decay signal is measured 

(Legchenko et Valla, 2002). However, in some 

rocks the geomagnetic field may be perturbed 

and FID measurements may fail (Roy et al., 

2008). For improving the MRS performance in 

the presence of magnetic rocks MRS could be 

used in the spin echo (SE) mode (Legchenko et 

al., 2010). In this case only the spin echo signal 

is measured. Under some conditions both FID 

and SE signals can be observed. 

We have developed a 3D mathematical model 

that allows computing MRS signal from 3D 

targets both in FID and SE modes. This model 

allows considering the field setup consisting of 

either one transmitting loop with number of 

separated receiving loops or the overlapped 

coincident loops. 

For experimental verification of the modeling 

routine we used an artificial water reservoir 

located in the southern part of the New 

Caledonia Island. In this pool, of 

approximately 80×30 m 2 large, the depth is 

varying from 1.5 to 4 m. A rectangular loop of 

100×50 m 2 was put around the pool. Rocks in 

this area are characterized by the magnetic 

susceptibility between 5e-4 and 5e-3 SIU thus 

perturbing the geomagnetic field. However 

within the pool these perturbations are 

relatively small and we were able to measure 

Experimental verification of a 3D model for MRS 44 

both FID and SE signals. The geomagnetic 

field was of 47246 nT and the Larmor 

frequency was about 2013 Hz. 

We have found that the relaxation times for the 

signal from water in the pool are: T1=1950 ms, 

T2=1400 ms, T2 * (FID)=100 ms and T2 * (SE)=125 

ms. The maximum signal amplitude was 

approximately 180 nV for the FID signal and 

120 nV for the SE signal (measured with the 

delay of 256 ms between the pulses). 

Under these conditions numerical modeling of 

the MRS signal from water in the pool showed 

a good correspondence between observed and 

theoretical signals for both FID and SE 

measurements. 

References 

Girard, J-F, M. Boucher, A. Legchenko, and J-M. 

Baltassat (2007): 2D magnetic resonance 

tomography applied to karstic conduit imaging. 


Hertrich, M., A.G. Green, M. Braun, and U. 

Yaramanci (2009): High-resolution surface 

NMR tomography of shallow aquifers based on 

multioffset measurements. Geophysics, 74, 47- 

59. 

Legchenko, A.V., and O.A. Shushakov (1998): 

Inversion of surface NMR data. Geophysics, 63, 

75-84. 

Legchenko, A., and P. Valla (2002): A review of 

the basic principles for proton magnetic 

resonance sounding measurements. Journal of 


Legchenko, A., J.M. Vouillamoz, J. Roy (2010): 

Application of the magnetic resonance sounding 

method to the investigation of aquifers in the 

presence of magnetic materials. Geophysics 75: 

L91–L100. 

Legchenko, A., M. Descloitres, C. Vincent, H. 

Guyard, S. Garambois, K. Chalikakis and M. 

Ezersky (2011): Three-dimensional magnetic 

resonance imaging for groundwater. New 

Journal of Physics, 13, 025022, doi: 

10.1088/1367-2630/13/2/025022. 

Roy, J., A. Rouleau, M. Chouteau, M. Bureau 

(2008): Widespread occurrence of aquifers 

currently undetectable with the MRS technique 

in the Grenville geological province, Canada. 




Comparison of borehole and surface NMR-inferred water content profiles 45 

Comparison of borehole and surface NMR-inferred water content profiles 

Andreas P. Mavrommatis 1* , Jan O. Walbrecker 1 , Rosemary Knight 1 

1 Department of Geophysics, Stanford University, Stanford, California, USA. 

* andreasm@stanford.edu 

The direct comparison of borehole and surface 

nuclear magnetic resonance (NMR) 

measurements made over the same area can 

provide useful insights about both the 

reliability and limitations of surface NMR. Our 

area of study is near Lexington, Nebraska, in 

the central United States, overlying the High 

Plains Aquifer, which is one of the largest and 

most important aquifers in the U.S. 

We use borehole NMR measurements of 

relaxation time distributions, T2, and electrical 

resistivity, acquired in a 150-m deep borehole 

drilled at the site in November 2009 (Knight et 

al., 2012). Because surface NMR measures a 

different transverse relaxation time constant, 

referred to as T2*, we transform the measured 

T2 distributions to pseudo-T2* distributions 

following Knight et al., 2012, accounting for a 

magnetic field inhomogeneity effect and an 

instrument dead time. 

In the forward modeling stage, we use the 

borehole-determined water content, pseudo- 

T2*, and resistivity as input to predict the 

surface-NMR response for this site. We 

explore the effects of discretizing water 

content and resistivity models at different 

resolutions on the predicted surface-NMR 

sounding curves. 

We analyze two sets of surface-NMR data that 

were acquired at the site in April 2009 and 

April 2012. We process a total of 768 

recordings for the 2009 data set and 1232 

recordings for 2012. Signal processing 

includes noise cancellation using reference 

recordings at three locations around the field 

site, removal of outliers, band-pass filtering, 

stacking of recordings for each pulse moment, 

and fitting. We invert the surface-NMR data 

sets using QT inversion (Müller-Petke and 

Yaramanci, 2010) and estimate the predicted 

water content profiles and T2* depth 

distributions. Various inversion parameters are 

explored, including smoothing and mono- vs. 

multi-exponential fitting. 

Preliminary results suggest the presence of a 

systematic difference between the observed 

and modeled surface-NMR data. Modeled 

signal amplitudes are consistently larger, by as 

much as a factor of three, than observed in the 

2009 and 2012 surface-NMR measurements. 

Because signal amplitude is linearly related to 

water content, we observe the same 

discrepancy when comparing borehole- and 

surface-NMR water content profiles. We are 

assessing possible sources for this discrepancy, 

such as the quality of the T2 to T2* 

transformation and the influence of magnetite 

in the pore space of the subsurface materials. 

References 

Knight, R., Grunewald, E., Irons, T., Dlubac, K., 

Song, Y., Bachman, H. N., Grau, B., Walsh, D. 

J., Abraham, D., Cannia, J. (2012): Field 

experiment provides ground truth for surface 

nuclear magnetic resonance measurement. 

Geophys. Res. Lett., 39, L03304. 

Müller-Petke, M., Yaramanci, U. (2010): QT 

Inversion – Comprehensive use of the complete 

surface NMR data set. Geophysics, 75, WA199- 

WA209. 



MRSMatlab – a toolbox for modeling, processing, and inverting surface-NMR data 46 

MRSMatlab – a toolbox for modeling, processing, and inverting surface- 

NMR data 

Mike Müller-Petke 1 , Jan O. Walbrecker 2 , S. Costabel 3 , T. Günther 1 , M. Hertrich 4 




4 ETH Zurich, Institute of Geophysics, Switzerland 

Mike.mueller-petke@liag-hannover.de 

Surface Nuclear Magnetic Resonance (SNMR) 

is a geophysical technique tailored for 

exploring groundwater occurrences in the 

shallow subsurface. Many groups worldwide 

have contributed significant improvements to 

the technique over the last decade, covering all 

important segments such as data acquisition, 

processing, forward modeling, and inversion. 

We have fused many of the recent advances 

into the single open-source software toolkit 

MRSmatlab. The software consists of various 

modules for data processing, forward 

modeling, and inversion of surface-NMR data. 

For processing, data can be imported from all 

currently available commercial surface-NMR 

systems (import of raw as well as preprocessed 

data is facilitated). Processing supports 

enhanced data inspection, digital filtering, 

spike suppression, data fitting, and noise 

cancellation employing one or more reference 

channels. 

Forward modeling currently features setups of 

coincident transmitter and receiver loops of 

circular, square, or figure-8 geometry. 

Arbitrary 1D electrical-conductivity structures 

can be included. Single and double-pulse 

surface-NMR experiments can be modeled to 

study the effect of water content and the T1 

relaxation parameter, respectively. For 

improved forward modeling off-resonance 

excitation can be included (Walbrecker et. al, 

2011a) 

The inversion implemented in MRSmatlab is 

based on the recently introduced QT-Inversion 

approach (Müller-Petke and Yaramanci, 2010) 

with improved performance, supporting 

complex surface-NMR data as well as 

smooth/layered model discretization and 

mono/multi-exponential decay times. The most 

recent feature is the inversion of double-pulse 

data to obtain the T1 relaxation parameter 

based on pcPSR (Walbrecker et.al. 2011b). 

The software package is frequently maintained, 

under continuous development, and publicly 

available to the surfacfe-NMR community 

through a website. 

References 

Mueller-Petke, M. & Yaramanci, U. (2010): QT 

inversion --- Comprehensive use of the complete 

surface NMR data set. Geophysics, SEG, 75 (4), 

WA199-WA209. 

Walbrecker, J. O., Hertrich, M. & Green, A. G. 

(2011a): Off-resonance effects in surface nuclear 

magnetic resonance. Geophysics, SEG, 76 (2), 

G1-G12. 

Walbrecker, J. O., Hertrich, M., Lehmann-Horn, J. 

A. & Green, A. G. (2011b): Estimating the 


Geophysics, SEG, 76 (2), F111-F122. 



Researching vertical resolution of SNMR by using numerical simulation 47 

Researching vertical resolution of SNMR by using numerical simulation 

Wang Peng 1 ,Zhengyu Li 1 ,Fei Yan 1 

1 China University of Geosciences,Wuhan,PRC 

pwhope@163.com 

Abstract 

At present, few geophysicists research 

resolution of SNMR. There are many factors 

impacting resolution of SNMR, they relate to 

the whole process from excitation to data 

processing. There is no strict definition of 

resolution of SNMR in other paper, and a 

cursory definition of resolution of SNMR has 

been given in this paper. We can say that the 

vertical resolution of SNMR is the minimum 

thickness that we can recognize along with the 

vertical direction of the strata, the horizontal 

resolution of SNMR is the minimum width that 

we can recognize along with the horizontal 

direction of the strata. There are many factors 

affecting the resolution of SNMR, which exist 

in the whole process including excitation, 

collection, data processing and integrated 

interpretation.These factors can be divided into 

natural factors and hunman factors. The natural 

factors include strata resistivity, geomagnetic 

field intensity, the dip angle of geomagnetic 

field, the type of the waterstone and so on.The 

hunman factors include the shape and size of 

the coil , the number and the value of the pulse 

and so on. 

In the uniform half-space, with the method 

of forward numerical simulation, the SNMR 

forward models for single water layer in 

different factors are caculated by Samogon 

software.In this paper six factors have been 

discused, it includes the dip angle of 

geomagnetic field, the size of the coil, the 

value of T2*,the water content of the aquifer, 

the thickness and depth of the aquifer, and 

related q-E0 figures are drawn. These figures 

can reflect how the factors affect the vertical 

resolution of SNMR. Besides, it can be 

induced that the relationship between the 

resolving power of SNMR and the aquifer with 

thin thickness or low water content. The results 

will provide theoretical basis for exploring 

groundwater with SNMR method. 



Study on Factors Affecting SNMR Vertical and Lateral Resolution 48 

Study on Factors Affecting SNMR Vertical and Lateral Resolution 

Fei Yan, Zhenyu Li, Wang Peng, Zunping Hu, Yuchao Xu, Huangjian Wu 


kdjf_025@126.com 

There are many factors affecting the resolution 

of surface nuclear magnetic resonance (shorted 

for SNMR), which exist in the whole process 

including excitation, collection, data 

processing and integrated interpretation. The 

resolution of SNMR can be divided into the 

vertical resolution and the lateral resolution. 

The paper mainly make forward numerical 

simulation for aquiferous cylinders in the 

uniform half-space to study the variations of 

SNMR signal amplitudes affected by the water 

content , the thickness and the depth of the 

aquiferous body, as well as the stratigraphic 

conductivity. The q-E0 figures are drawn and 

generalize the resolving power of SNMR for 

low water content or thin aquifer. The results 

will provide theoretical basis for exploring 

groundwater with SNMR method. 

In the numerical simulation, transmittance and 

reception with the same loop is used as the 

working pattern, and aquiferous cylinder is 

used as the water model. The diameter of the 

cylinder evaluates the lateral resolution, while 

the thickness of the cylinder evaluates the 

vertical resolution. According to the field test 

experience, E0max = 50nV is defined as the 

measuring standard of the recognizable SNMR 

response, which means if the detected SNMR 

response meets the standard, there is 

groundwater in the formation, otherwise it 

can't be affirmed that there is groundwater in 

the formation. E0max represents the maximum 

of the initial amplitude. Aquiferous body 

which is up to the standard is called 

recognizable aquiferous body. 

According to the caculational results, some 

conclusions can be shown as followed: 

1. When the diameter of aquiferous cylinder is 

fixed, with the increase of the buried depth of 

aquiferous body, thickness of the recognizable 

aquiferous body increase as well. The vertical 

resolution of SNMR declines; when the 

thickness of the aquiferous cylinder is fixed, 

the diameter of the recognizable aquiferous 

body becomes larger along with the increase of 

the burial depth of aquiferous body, and the 

increasing range largens, which means the 

lateral resolution of SNMR declines. 

2. When the diameter of aquiferous cylinder is 

fixed, the thickness of the recognizable 

aquiferous body decreases with the increase of 

the burial depth of aquiferous body, and the 

rangeability reduces gradually, which means 

the vertical resolution of SNMR increases; 

when the thickness of the aquiferous cylinder 

is fixed, the diameter of the recognizable 

aquiferous body will become smaller with the 

increase of the water content of aquiferous 

body, which means the aquiferous body with 

larger water content has higher lateral 

resolution of SNMR. 

3. when the diameter of aquiferous cylinder is 

fixed, if formation resistivity changes from 

1Ω•m to 1000Ω•m, the thickness of the 

recognizable aquiferous body will decrease 

rapidly at first and then increase a little , which 

means the vertical resolution of SNMR is 

highest when the resistivity is a specific value; 

when the thickness of the aquiferous body is 

fixed, the diameter of the recognizable 

aquiferous body becomes smaller with the 

increase of formation resistivity, which means 

the lateral resolution of SNMR enhances. 

noise interference. 

References 

Aihua Weng, Zhoubo Li, Xueqiu Wang. (2002): 

Numerical study of SNMR response. Computing 

Techniques For Geophysical and Geochemical 

Exploration, 24(2): 97~101. 

Goldman M, Rabinovich B, Rabinovich M, et al. 

(1994): Application of the integrated NMR- 

TDEM method in groundwater exploration in 

Israel. Journal of Applied Geophysics, 31(4): 

27~52. 

Shusakov, O.A., Legchenko,A.V.. (1995): Surface 

NMR applied to an electroconductive medium. 

Geophysics.Prosp.,vol.43, 623~633. 



Advances in hydrological 

parameterization 



49

Recent advancements in NMR for characterizing the vadose zone 50 

Recent advancements in NMR for characterizing the vadose zone 

David Walsh 1 , Elliot Grunewald 1 , Hong Zhang 1 , Paul Ferre 2 and Andrew Hinnell 2 

1 Vista Clara, Inc., Mukilteo, WA, USA, davewalsh@vista-clara.com, 2 University of Arizona, Tucson AZ, USA 

Until recently, most applications of NMR 

in hydrogeology have focused on detecting 

and characterizing groundwater in the 

saturated zone. Another target for 

hydrogeophysical methods is water in the 

vadose zone, the dynamics of which 

control contaminant migration, 

groundwater recharge, evapotranspiration, 

and soil stability. The challenge of 

characterizing water in the vadose zone by 

NMR is that the signals are typically very 

weak (due to low water content) and very 

short (due to concentration of water on 

grain surfaces or in the smallest available 

pores). Here we present improvements in 

NMR geophysics technology over the past 

4 years, and demonstrate the application of 

these technologies to vadose zone 

characterization. 

To address the challenges of using Earth’s 

field surface NMR instrumentation to 

detect and characterize water in the vadose 

zone, we designed a modified GMR 

instrument with faster switching and higher 

powered electronics. This instrument has a 

measurement dead-time of 2.8 ms, an 

instantaneous power output of 7000 V and 

800 A, and a noise floor of 0.5 nV/rt(Hz). 

The new instrument was used to collect 

and interpret surface NMR data at active 

vadose zone investigation sites in the 

western United States. First, the equipment 

was used to detect, image and quantify 

water infiltrating into the ground at a 

managed aquifer storage and recovery 

(ASR) facility in Tucson Arizona. Analysis 

of this data indicates that the surface NMR 

tool was able to measure the recharge 

speed of the initial wetting front, and 

quantify some, but not all of the water that 

was recharged. Further analysis showed 

that infiltrating water filled larger pores, 

temporarily, and the water filled pore size 

distribution in the top 15m returned to its 

“dry“ condition within 3 weeks of the end 

of the surface water infiltration. 

Additional surface NMR measurements at 

vadose zone investigations in Washington, 

Nebraska and Kansas demonstrated that 

the equipment could detect and image the 

location of bound and perched water to 

depths of at least 25m. Borehole NMR logs 

at these sites indicated that the surface 

NMR measurements were detecting only a 

portion of the bound water. Additional 

borehole NMR measurements in eastern 

Kansas demonstrated the ability of NMR 

logging to detect and quantify transient 

water content in the vadose zone. In this 

case decayed tree roots were temporarily 

saturated with water, following a local 

stream flood event. 

Finally, a new geotechnical NMR 

instrument has been developed and 

demonstrated for detecting and 

characterizing soil moisture in the top 1m 

of the subsurface. This tool generates a 

boosted static gradient field, and performs 

non-invasive CPMG NMR measurements 

in the low RF band (40 kHz – 500 kHz) 

with an echo spacing of 1 ms or less. 

Preliminary field tests showed that the tool 

can accurately measure water content and 

its T2 distribution at multiple depths, in 

both dry and wetted conditions, with total 

scan times of approximately 3 minutes. 

Acknowledgement: This material is based upon 

work supported, in part, by the US Department of 

Energy under Grant numbers DE-FG02- 

08ER84979 and DE-SC000423, and US Army 

Contract # W912HZ-12-P-0018. Any opinions, 

findings, and conclusions or recommendations 

expressed in this material are those of the author(s) 

and do not necessarily reflect the views of the US 

Department of Energy or the US Army. 



Direct inversion for water retention parameters from MRS measurements in the 

saturated/unsaturated zone – a sensitivity study 51 

Direct inversion for water retention parameters from MRS measurements 

in the saturated/unsaturated zone – a sensitivity study 

Stephan Costabel 1 and Thomas Günther 2 




The idea of applying MRS for characterizing 

the vadose zone has been discussed for almost 

ten years. First experiments showed that it is 

actually possible to identify water in the 

unsaturated zone (e.g. Roy and Lubczynski, 

2005). However, the reliability of this 

information is usually quite poor due to low 

signal-to-noise ratios (S/N). Moreover, it has 

become apparent that the usual MRS 

interpretation concept based on smooth 

inversion techniques is not suitable to estimate 

hydraulic parameters, unless time-lapse MRS 

is performed to monitor water fluxes in the 

subsurface (Roy and Lubczynski, 2005; 

Costabel and Yaramanci, 2011). 

Costabel and Yaramanci (2011) suggested an 

alternative MRS inversion approach for 

estimating water retention (WR) parameters. It 

is based on the soil physical parameterization 

of the capillary fringe (CF), i.e. the transition 

between the unsaturated and the saturated 

zones. In doing so, a WR model (e.g. after 

Brooks and Corey, 1964) that describes the 

water content increase in the capillary fringe is 

included in the MRS forward operator. 

Consequently, the CF inversion approach 

directly provides the WR parameters and, 

following the common soil physical concept of 

piston flow, it becomes possible to estimate the 

unsaturated hydraulic conductivity as a 

function of the saturation degree. 

We have developed and investigated the CF 

inversion approach further to account for 

different WR models and to assess its general 

applicability. Its forward operator generally 

consists of five parameters: the saturated and 

the residual water content, a parameter for the 

height of the CF, a parameter describing the 

gradient of the water content increase in the 

CF, and the water table. However, the residual 

water content for our examples is generally 

neglected. This is in common with the usual 

assumption that water related to the smallest 

pores is unvisible with MRS due to the 

instrumental dead time. 

A sensitivity study based on both synthetic and 

real data analyzes the resolution properties, the 

uncertainties and the cross covariances of the 

involved parameters. The inversion is realized 

with the software package GIMLi using a 

Marquardt-Levenberg minimization scheme 

using logarithmic barriers to keep the parameters 

within reasonable ranges along with the 

computation of model uncertainties. 

For every WR model, we found that it is not 

meaningful to invert for all parameters at once. 

At least, an estimate of the CF’s height or the 

water table must be available as a-priori 

information. Otherwise the CF inversion 

cannot reliably be applied, even when the noise 

level is unrealistically low. The accuracy of the 

saturated water content is generally high with 

errors less than 1%. Depending on the actual 

noise level, the uncertainties of the other 

parameters are in the range of 10 to 100%, i.e., 

only for moderate noise conditions the CF 

inversion can provide WR parameters accurate 

enough to estimate the unsaturated hydraulic 

conductivity. However, the CF inversion is a 

first attempt to interpret MRS measurements 

with the focus on hydraulic parameters 

characterizing the vadose zone. 

References 

Brooks, R. H., Corey, A.T. (1964), Hydraulic 

properties of porous media. Colorado State 

University Papers 3. 

Costabel, S., Yaramanci, U. (2011): Relative 

hydraulic conductivity in the vadose zone from 

magnetic resonance sounding – Brooks-Corey 

parameterization of the capillary fringe. 

Geophysics, 76 (3), 61-71. 

Roy, J., Lubczynski, M. W. (2005): MRS multiexponential 

decay analysis: aquifer pore-size 

distribution and vadose zone characterization. 

Near Surface Geophysics, 3(4), 287-298. 



MRS subsurface parametrization for coupled hydrological Marmites model 52 

MRS subsurface parametrization for coupled hydrological Marmites model 

Baroncini-Turricchia, G. 1,2,* ; Francés, A.P. 1 ; Lubczynski, M.W. 1 ; Martínez-Fernández, J. 2 ; 

Roy, J. 3 

1 ITC-Twente University, Hengelosestraat 99, Enschede (NL) 

2 CIALE-Universidad de Salamanca, Calle Duero 12 37185 Villamayor, Salamanca (ES) 

3 IGP, cp 48671 csp van Horne, Outremont, QC, Canada H2V 4T9, former ITC 

* coprolog@yahoo.com 

This study presents MRS data integration in 

the transient and distributed MARMITES- 

MODFLOW (MM-MF) coupled models 

(Frances et al. 2011) that simulate the water 

fluxes between land surface, unsaturated and 

saturated zones. The MM-MF allows to 

compute spatio-temporally a water balance at 

the catchment scale. 

The coupled models like MM-MF, due to their 

spatio- temporally variable input fluxes are 

better constrained, so more reliable, than the 

standard groundwater models. They are 

particularly valuable when facilitated by good 

monitoring network and supported by reliable 

aquifer system parameterization. We present 

MRS data integration following Lubczynski 

and Roy (2007) in the coupled Carrizal 

catchment MM-MF model. The Carrizal 

catchment (73 km 2 ) is located near Salamanca 

in Spain. It is a hilly, agricultural land, 

composed of sedimentary unconsolidated rocks 

overlain by a sandy soil. The bottom of 

unconfined Carrizal aquifer is at depth of 10- 

60 m b.g.s. and a water table at ~4-12 m b.g.s. 

The study area is well-equipped with weather 

stations, soil moisture and discharge stations 

operating since 1999. Additionally in 2009, a 

network of 12 piezometers registering 

groundwater levels hourly was installed with 

the objective of studying the shallow alluvial 

aquifer regime to assess sustainability of 

groundwater resources under the increasing 

water use, mainly due to the expansion of 

irrigation practices. However in that study area 

there are no aquifer pumping tests to facilitate 

aquifer system parameterization. For that 

purpose we used non-invasive MRS technique 

which allows to define most important 

subsurface parameters in non-invasive time- 

and scale- efficient manner providing valuable 

constrain for the model calibration. 

To parametrize Carrizal aquifer for the MM- 

MF coupled model, we carried out in total 12 

MRS surveys well distributed within the 

Carrizal catchment. These surveys were done 

in 2010 and 2011 using NUMIS Lite MRS 

equipment. Our aim was to define: (i) 

geometry of the shallow unconfined aquifer, 

i.e. aquifer bottom and water table; (ii) aquifer 

transmissivity; (iii) aquifer specific yield. The 

aquifer geometry was defined by analyzing the 

water content and pore size distribution along 

the inverted profiles. For the aquifer 

transmissivity we used MRS forward approach 

described in Plata and Rubio (2008). Finally, 

for estimate of specific yield we applied the 

approach presented by Vouillamoz et al. 2012. 

The MM-MF model calibration showed a good 

agreement between MRS-derived specific 

yield and transmissivity and coupled model 

parameters. The Carrizal study confirmed the 

appropriatness of the forward method of MRS 

parametrization and its suitability for data 

integration in coupled models. 

References 

Francés, A.P., et al., 2011. Towards an improved 

assessment of the water balance at the catchment 

scale: a coupled model approach. In: Estudios en 

la zona no saturada del suelo: vol.X: ZNS11 

Proceedings, 19-21 October 2011, Salamanca, 

Spain: e-book/ p.321-326. 

Lubczynski, M.W. and J. Roy, 2007. Use of MRS 

for hydrogeological system parameterization and 

modeling. Boletin Geologico y Minero,. 118(3): 

p.509-530. 

Plata, J.L. and F.M. Rubio, 2008. The use of MRS 

in the determination of hydraulic transmissivity: 

The case of alluvial aquifers. Journal of Applied 

Geophysics. 66(3-4): p.128-139. 

Vouillamoz, J.M., S.Sokheng, O.Bruyere, D. 

Caron, L. Arnout 2012. Towards a better 

estimate of storage properties of aquifer with 

magnetic resonance sounding. Journal of 

Hydrology, accepted in press. 



An efficient full coupled inversion of aquifer test, MRS and TEM data 53 

An efficient full coupled inversion of aquifer test, MRS and TEM data 

Troels N. Vilhelmsen, Ahmad A. Behroozmand, Steen Christensen, Toke Højbjerg Nielsen, 

and Esben Auken 

Department of Geosciences, Høegh-Guldbergs Gade 2, 8000 Aarhus C, Aarhus University, Denmark 

troels.norvin@geo.au.dk 

Parameters estimated by MRS can be related 

empirically to hydraulic properties such as 

hydraulic conductivity or transmissivity if it is 

calibrated to nearby aquifer tests. Traditionally 

this is done independently by an analytical 

analysis of the aquifer test in order to get 

estimates of storage parameters and 

transmissivity. These are subsequently 

calibrated/correlated to the parameters 

estimated by MRS inversion through an 

empirical relation. Examples of this are given 

by Nielsen et al. (2011); Vouillamoz et al. 

(2002); and others. To achieve good results 

using this methodology, analytical models 

which agree with the field conditions must 

exist. However, even if such models exist the 

full potential for the resolution of both the 

MRS dataset and the aquifer test dataset might 

not be achieved due to limitations of 

parameters estimated by the individual 

methods. 

Here we present a new methodology for a full 

coupled inversion between an aquifer test, 

MRS and TEM. It has been shown that 

inversion results can be improved using a joint 

inversion of MRS and TEM datasets 

(Behroozmand et al. 2012). In this context, 

especially the improved resolutions of layer 

thicknesses provide valuable information when 

analyzing aquifer tests. Traditionally aquifer 

tests are only used to estimate transmissivity 

(namely the hydraulic conductivity times the 

thickness), since the responses measured will 

only be sensitive to the potential for the aquifer 

to conduct water. If hydraulic conductivity is 

to be determined, the layer thickness must be 

provided through other sources; this typically 

being through borehole information. However, 

in the present study we analyze a two aquifer 

system, where only the upper aquifer is 

penetrated by a borehole. The presence of the 

deeper aquifer is only seen as a secondary 

drawdown response measured in observation 

wells in the upper aquifer and through the 

MRS and TEM soundings. Based on this 

system we suggest and demonstrate a new 

coupled inversion approach. We show that 

reliable estimates can be achieved for a 

number of parameters pertaining to each 

geological layer: water content, decay time, 

resistivity (of low resistivity layers), hydraulic 

conductivity and storage coefficients. 

Based on the results we advocate the use of 

numerical flow models when analyzing aquifer 

tests due to their versatility, and the potential 

for the proposed method to couple multiple 

MRS soundings to one aquifer test through 

regularized constraints between parameters. 

The coupled models were calibrated using 

PEST (Doherty 2010), and the forward 

responses were calculated using em1dinv 

(Auken et al. 2012) for the geophysical models 

and a radial-symmetric version of MODFLOW 

(Clemo 2002) for the aquifer test. 

References 

Auken, E., C. Kirkegaard, and A. V. Christiansen, 

2012, EM1DINV part A: A highly versatile and 

robust inversion code implementing accurate 

system forward modeling and arbitrary model 

constraints: Geophysical Prospecting, Submitted 

Behroozmand, A. A., Auken, E., Fiandaca, G., and 

Christiansen, A. V. (2012). "Improvement in 

MRS parameter estimation by joint and laterally 

constrained inversion of MRS and TEM data." 

Geophysics, 77(4), 1-10. 

Clemo, T. "MODFLOW-2000 for cylindrical 

geometry with internal flow observations and 

improved water table simulation." Boise, Idaho. 

Doherty, J. (2010). PEST Model-Independent 

Parameter Estimation, User Manual: 5th edition. 

Watermark Numerical Computing. 

Nielsen, M. R., Hagensen, T. F., Chalikakis, K., 

and Legchenko, A. (2011). "Comparison of 

transmissivities from MRS and pumping tests in 

Denmark." Near Surface Geophysics, 9, 211- 

223. 

Vouillamoz, J.-M., Descloitres, M., Bernard, J., 

Fourcassier, P., and Romagny, L. (2002). 

"Application of integrated magnetic resonance 

sounding and resistivity methods for borehole 

implementation. A case study in Cambodia." 




The integration of logging and surface NMR for mapping spatial variation in hydraulic 

conductivity 54 

The integration of logging and surface NMR for mapping spatial variation 

in hydraulic conductivity 

Rosemary Knight 1 , Elliot Grunewald 2 , Katherine Dlubac 1 , David Walsh 2 and James Butler 3 

1 Stanford University, Department of Geophysics, Stanford, CA, USA 

2 Vista Clara Inc., Mukilteo, WA, USA 

3 Kansas Geological Survey, Lawrence, KS, USA 

rknight@stanford.edu 

Over the past two decades there has been 

growing interest in the use of the surface NMR 

method as a means of characterizing 

groundwater aquifers. The surface NMR 

method can be described by the same basic 

physics as the logging NMR measurement. 

Logging NMR has been used for decades in 

the petroleum industry to obtain estimates of 

permeability from the measured relaxation 

time constant T2ML, which is the mean log of 

the acquired distribution of T2 relaxation times. 

The basic assumption is that T2ML -1 is directly 

related to the surface-area-to-volume ratio of 

the pore space S/V through the surface 

relaxivity �: T2ML -1 = � S/V. By assuming a 

constant value for �, and using a Kozeny- 

Carman type of relationship with NMRderived 

porosity, T2ML can provide an estimate 

of permeability, or hydraulic conductivity K. 

Unlike the logging measurement, the 

surface NMR measurement cannot readily 

acquire T2ML data; instead a measure of the free 

induction decay (FID) yields the relaxation 

time constant T2ML*, which is the mean log of 

the acquired distribution of T2* relaxation 

times. T2ML* can be related to S/V, but in the 

presence of inhomogeneity in the background 

field this relationship can be completely 

obscured (Grunewald and Knight, 2011). 

Background field inhomogeneity results in 

relaxation due to static and diffusion-related 

dephasing during the measurement, 

characterized by the relaxation time T2IH. This 

leads to an accelerated decay in surface NMR, 

causing T2ML* to underestimate T2ML. 

The methodology we propose for using 

surface NMR measurements of T2ML* to 

estimate K at a site involves two steps. First 

co-located measurements of T2ML and K are 

used to determine the form of the empirical 

relationship required to transform 

measurements of T2ML to estimates of K. Next 

co-located logging and surface NMR 

measurements are used to determine how to 

transform measurements of T2ML* to T2ML. This 

proposed methodology is possible due to 

recent advancements in technology that have 

made available the Javelin NMR logging tool, 

designed specifically for use in small-diameter 

water wells. In addition to being deployed in a 

borehole, the Javelin can also be deployed with 

a direct-push system. 

We have tested this methodology with data 

sets from two sites: one from Nebraska 

(Knight et al., 2012; Dlubac et al., 2012), and 

one acquired at the GEMS site in Kansas. In 

developing the transform from T2ML to K, we 

used a modified form of the Schlumberger- 

Doll research equation. We determined the 

values for the empirical constants in this 

equation by optimizing the agreement between 

the measured K and K predicted from the NMR 

data. In Nebraska measured K was measured 

with a wellbore flowmeter; in Kansas K was 

measured with a direct push permeameter. 

Developing the transform from T2ML* to 

T2ML requires quantifying the magnitude of 

T2IH. In the Nebraska study, we had obtained 

an estimate of T2IH from measurements of the 

variability in the total magnetic field measured 

in a borehole. In the Kansas study, we obtained 

an estimate of T2IH through comparison of the 

surface and the logging data. In both cases we 

found excellent agreement between K 

estimated from the surface NMR data and 

measured K. The use of these transforms raises 

a number of questions related to scale and 

heterogeneity, the focus of ongoing research. 

References 

Grunewald, E. and R. Knight, Near Surface 

Geophysics, 9 (2), 169-178 doi:10.3997/1873- 

0640.2010062, 2011. 

Knight, R., et al., Geophy. Res.Lett., 39, L03304, 

doi:10.1029/2011GL050167, 2012. 

Dlubac, K., et al., submitted to Water Resources 

Research, 2012 



Hard rock hydrogeophysics applied to hydrological model parameterization - Sardón 

catchment case study (Salamanca, Spain) 55 

Hard rock hydrogeophysics applied to hydrological model 

parameterization - Sardón catchment case study (Salamanca, Spain) 

Alain Pascal Francés a , Jean Roy b , Maciek Lubczynski a 

a International Institute for Geo-Information Science and Earth Observation (ITC, Netherland), b IGP (Canada) 

frances08512@itc.nl 

Modelling of groundwater systems is 

challenging because of subsurface 

heterogeneity and typical data scarcity due to 

the high cost of invasive methods. Modelling 

of hard rock systems is even more difficult 

because of extraordinary heterogeneity. In hard 

rock aquifers, the upper weathered layer, socalled 

saprolite, has typically a storage 

function while the underlying fissured layer 

has a transmissive function (Dewandel et al., 

2006; Lloyd, 1999). In this study, we propose 

to apply hydrogeophysics to assess the aquifer 

parameters and geometry. These data are 

further integrated in a transient and distributed 

hydrological model of the land surface, 

unsaturated and saturated zones (MARMITES- 

MODFLOW coupled models). 

We applied the proposed methodology to 

characterize hydrogeologically a hard rock 

aquifer within Sardón catchment (~80 km 2 ), 

located in the Iberian Meseta (west of 

Salamanca, Spain). The Sardón catchment is 

predominantly composed of two micas granites 

and is affected in its centre by a NNE-SSW 

fault (F1) along which the main Sardón stream 

is located. Another family of faults (F2), with 

NE-SW direction, also controls the catchment 

hydrology. Our objective was to retrieve the 

spatial variation of the saprolite and fissured 

layers, namely their thickness and hydraulic 

properties. Hydrogeophysics was used to 

complement the classical methods (geological 

mapping, remote sensing and aerial photograph 

analysis of fracture detection) as following: i) 

subsurface characterization of weathered layers 

using vertical electrical soundings (VES) at 61 

locations, electromagnetic (FDEM) transect 

perpendicular to the main valley (~3 km) and 

electrical resistivity tomography (ERT) at 13 

locations; ii) depth of groundwater table 

assessment using ground penetrating radar 

(GPR) to complement the information of the 

piezometric network; iii) depth-wise 

subsurface water content and aquifer 

transmissivity quantification using magnetic 

resonance sounding (MRS) at 15 locations. We 

realized a drilling campaign of 5 deep 

boreholes (25 to 48 m deep) to validate the 

hydrophysical interpretation and complement 

15 shallow piezometers bored in the alluvium. 

With the GPR method, combined with ERT, 

we could identify locally the water table 

(Mahmoudzadeh et al., 2012). Using the 

FDEM, VES and ERT methods, we were able 

to identify the saprolite and fissured layers. 

The sites surveyed with MRS at the hilltop 

showed the absence of signal, indicating low 

water content (< 2,5%) and/or high content of 

fines (silts/clays) in the saprolite. Along the 

thalweg, we obtained valid MRS signal at 

several places, namely at the intersection of the 

two major faults F1 and F2. However, the 1D 

interpretation of such data was not 

straightforward. Further analysis of the data 

involving comparison with other authors 

(Baltassat et al., 2005; Legchenko et al., 2006; 

Vouillamoz et al., 2005; Wyns et al., 2004) as 

well as processing using recently developed 

3D inversion of the MRS signal (Legchenko et 

al., 2011) may help to interpret the obtained 

data. The drilling of two boreholes at this place 

showed the presence of a thick saprolite layer, 

as well as another borehole drilled along the F1 

fault. The other 2 boreholes showed the 

absence of saprolite and found the fissured 

layer beneath the soil layer. The collected 

information, together with soil hydraulic 

properties and hydrometeorological data 

obtained from the monitoring network, were 

used to parameterize the system, assess water 

fluxes and calibrate the hydrological model to 

obtain the water balance at the catchment 

scale. 

The combination of the techniques applied in 

this study allowed: i) to identify the 

hydrodynamics of the Sardón aquifer; ii) to 

confirm the presence of the main prospective 

zone in the centre of the area where a regional 

fault zone drains the groundwater of the 

catchment; iii) to evidence through MRS a 

high-yield at the intersection of two major fault 

zones; iii) to provide the spatio-temporal 



Hard rock hydrogeophysics applied to hydrological model parameterization - Sardón 

catchment case study (Salamanca, Spain) 56 

variability of fluxes and estimate the water 

balance in the study area; iv) to define an 

efficient protocol of hydrogeological 

assessment in data scarce areas. 

References 

Baltassat, J.M., Legchenko, A., Ambroise, B., 

Mathieu, F., Lachassagne, P., Wyns, R., Mercier, 

J.L., Schott, J.J., 2005. Magnetic resonance 

sounding (MRS) and resistivity characterisation 

of a mountain hard rock aquifer: the Ringelbach 

Catchment, Vosges Massif, France. Near Surface 

Geophysics, 3(4): 267-274. 

Dewandel, B., Lachassagne, P., Wyns, R., 

Maréchal, J.C., Krishnamurthy, N.S., 2006. A 

generalized 3-D geological and hydrogeological 

conceptual model of granite aquifers controlled 

by single or multiphase weathering. Journal of 

hydrology, 330(1-2): 260-284. 

Legchenko, A., Descloitres, M., Bost, A., Ruiz, L., 

Reddy, M., Girard, J.-F., Sekhar, M., Mohan 

Kumar, M.S., Braun, J.-J., 2006. Resolution of 

MRS Applied to the Characterization of Hard- 

Rock Aquifers. Ground Water, 44(4): 547-554. 

Legchenko, A., Descloitres, M., Vincent, C., 

Guyard, H., Garambois, S., Chalikakis, K., 

Ezersky, M., 2011. Three-dimensional magnetic 

resonance imaging for groundwater. New 

Journal of Physics, 13(2): 025022. 

Lloyd, J.W. (Ed.), 1999. Water resources of hard 

rock aquifers in arid and semi-arid zones. Studies 

and reports in hydrology. UNESCO, Paris, 284 

pp. 

Mahmoudzadeh, M.R., Francés, A.P., Lubczynski, 

M., Lambot, S., 2012. Using ground penetrating 

radar to investigate the water table depth in 

weathered granites — Sardon case study, Spain. 

Journal of Applied Geophysics, 79(0): 17-26. 

Vouillamoz, J.M., Descloitres, M., Toe, G., 

Legchenko, A., 2005. Characterization of 

crystalline basement aquifers with MRS: 

comparison with boreholes and pumping tests 

data in Burkina Faso. Near Surface Geophysics, 

3(3). 

Wyns, R., Baltassat, J.-M., Lachassagne, P., 

Legchenko, A., Vairon, J., Mathieu, F., 2004. 

Application of proton magnetic resonance 

soundings to groundwater reserve mapping in 

weathered basement rocks (Brittany, France). 

Bulletin de la Societe Geologique de France, 

175(1): 21-34. 



A laboratory study to determine the effect of surface roughness and grain diameter on 

NMR relaxation rates of glass bead packs. 57 

A laboratory study to determine the effect of surface roughness and grain 

diameter on NMR relaxation rates of glass bead packs. 

Kristina Keating 

Rutgers University, Department of Earth and Environmental Sciences, Newark, NJ 

kmkeat@andromeda.rutgers.edu 

The NMR measurement is used in the earth 

sciences for the evaluation of petroleum 

reservoirs and aquifers because it can directly 

detect hydrogen, in hydrocarbons or in water, 

and is sensitive to pore geometry. While NMR 

measurements are used primarily to determine 

water or hydrocarbon content, the sensitivity of 

the measurement to pore geometry means that 

it has also be used to estimate the permeability 

of petroleum reservoirs and the hydraulic 

conductivity of aquifers (e.g. Yaramanci et al., 

1999; Freedman, 2006). 

The measured NMR signal is typically 

described by two parameters: the initial signal 

magnitude, which is proportional to the 

number of hydrogen molecules in the 

measured volume, and the average relaxation 

rate, R2ML. Early numerical work showed that 

R2ML is proportional to the inverse of the pore 

diameter, 1/d, for idealized pore shapes (i.e. 

spherical, cylindrical, or planar; Brownstein 

and Tarr, 1979). For these pore shapes, 1/d is 

equal to the ratio of the pore surface area to 

pore volume, S/V, scaled by a factor that 

accounts for pore shape (e.g. 3 for spherical 

pores). In the interpretation of NMR 

measurements on geologic material, which do 

not have idealized pore, it is often assumed 

that both 1/d and S/V are proportional to R2ML. 

However, these parameters can only be 

equated if the pore surface is smooth; for rough 

surfaces the difference between 1/d and S/V 

can be greater than one order of magnitude 

(Keating and Knight, 2010). This laboratory 

study was designed to evaluate the relationship 

between R2ML and both 1/d and S/V for 

materials with smooth and rough surfaces and 

to determine which parameter is relavent for 

the interpretation of NMR data. The results 

from this study are a critical step towards 

improving the relationship between R2ML and 

pore geometry and will ultimately help to 

improve NMR derived estimates of 

permeability and hydraulic conductivity. 

Sample materials were made from soda lime 

glass beads with varying grain diameter and 

specific surface area. Four sets of glass beads 

with a different range of grain diameters were 

used. The surface area of each set of glass 

beads was altered in three ways; one that 

removed surface paramagnetic impurities but 

only minimally changed the surface area and 

bead diameter and two that altered the surface 

area but only minimally changed the bead 

diameter. The specific surface area of each 

bead type was measured using the BET 

adsorption method; the average grain diameter 

was determined by laser particle analysis. 

Laboratory NMR measurements were collected 

on water saturated glass bead packs using a 2 

MHz Rock Core Analyzer (Magritek Ltd.). 

R2ML was plotted against both 1/d, estimated 

from the average grain diameter, and S/V, 

calculated from the specific surface area. A 

single linear function was not found to 

acurately represent the relationship between 

R2ML and 1/d. Two linear functions were 

needed to accurately fit the data: one for the 

non-etched samples and one for the etched 

samples. Conversely, a single linear function 

was found to accurately represent the 

relationship between R2ML and S/V (R 2 =0.97). 

The results from this study showed that, for 

materials with rough surfaces, S/V is the 

relavent parameter in the interpretation of 

NMR data. 

References 

Brownstein, K. R., and Tarr, C. E. (1979): The 

importance of classical diffusion on NMR 

studies of water in biological cells. Phys. Rev. A. 

Freedman, R. (2006): Advances in NMR logging. 

Journal of Petroleum Technology. 

Keating, K. and Knight, R. (2010): A laboratory 

study on the effect of Fe(II)-bearing minerals on 

nuclear magnetic relaxation rates. Geophysics. 

Yaramanci, U., Lange, G., Knödel, K. (1999): 

Surface NMR within a geophysical study of an 

aquifer at Haldensleben (Germany). Geophysical 

Prospecting 



A numerical study of the relationship between NMR relaxation and permeability in 

materials with large pores 58 

A numerical study of the relationship between NMR relaxation and 

permeability in materials with large pores 

Katherine Dlubac and Rosemary Knight 

Stanford University 

kdlubac@Stanford.edu 

NMR is a geophysical method of great interest 

for groundwater applications because it is able 

to provide estimates of permeability (k). The 

measured NMR parameters have been used to 

estimate k though empirical equations based on 

the Kozeny-Carman (K-C) relationship, which 

predicts k from porosity (�) and the ratio 

between the total surface area and the total 

volume of the pore space (S/V). The 

Schlumberger-Doll Research (SDR) equation, 

commonly used in petroleum applications on 

consolidated materials, modifies the K-C 

relationship by replacing (S/V) -1 with the mean 

log of T2 (T2ML) and modifying the exponent on 

�. It is given by kSDR=b� m T2ML n , where b 

accounts surface relaxivity (��m is most 

commonly equal to 4, and n is set equal to 2. 

The SDR equation is based on the assumptions 

that (1) bulk fluid relaxation (T2B) is negligible, 

and (2) because pores are small, relaxation 

occurs in the fast diffusion regime (RFD). By 

assuming the contribution of T2B is negligible, 

T2 -1 is equal to the surface relaxation rate, T2S -1 , 

and the form of the SDR equation for 

predicting k is valid. In the RFD, T2S -1 =�(S/V). 

However, the assumption that T2B is negligible 

and that relaxation occurs in the RFD may be 

violated in unconsolidated materials where 

pores can be relatively large. 

In this study, we examine the effects on k 

estimates when incorrectly assuming (1) the 

contribution of T2B and (2) the diffusion 

regime. When the contribution of T2B is not 

negligible, T2 -1 =T2S -1 + T2B -1 and kSDR should be 

modified to kSDR-BF=b� m ((T2ML -1 -T2B -1 ) -1 ) n . 

When pores are larger than a critical size, 

relaxation occurs in the slow diffusion regime 

(RSD) in which T2S -1 =(2/3)D(S/V) 2 , where D is 

the self-diffusion coefficient of the fluid, and n 

in kSDR should be set equal to 1. 

We chose to investigate these effects through 

simulations on numerical grain packs. Six 

homogeneous Finney packs were created with 

grain radii ranging from 5.9e-5 to 3.2e-3 m 

(fine sand to gravel). For each pack, the NMR 

response was simulated for seven � values 

ranging from 1e-5 to 1e-3 m/s using a random 

walk model that implemented the First- 

Passage-Time technique (Toumelin et al., 

2003). The walkers were constrained to start in 

an initial location within a cubic subset in the 

center of each pack. The simulated relaxations 

occurred in the intermediate and slow diffusion 

regimes and were inverted for T2 distributions. 

The T2 values of the highest order relaxation 

modes ranged from 0.37 to 2.9 s. The k, �, and 

S/V of each pack were calculated on the 

volume of the pack likely to have been 

sampled by the walkers. The Marching Cubes 

technique was used to calculate S/V, which 

ranged from 6.3e4 to 2.8e3 m -1 . The Navier- 

Stokes based lattice-Boltzmann method was 

used to calculate the true k (ktrue), which ranged 

from 1.2e-17 to 5.2e-15 m 2 . 

For all packs of a given � value, we optimized 

the fit between kSDR and ktrue assuming 

relaxation occurred in either the RFD or the 

RSD. Regardless of whether we assumed the 

RFD or the RSD, the kSDR estimates showed 

relatively poor agreement with ktrue, differing 

by up to an order of magnitude. We then 

performed the same optimization, accounting 

for T2B by substituting kSDR-BF for kSDR. We 

found that by assuming the RFD, there was little 

improvement in the agreement between kSDR 

and ktrue. However, by correctly assuming the 

RSD, almost all of the kSDR-BF estimates were 

within a factor of 3 of ktrue. This work shows 

that the contribution of T2B can be significant 

in pores with large radii (>6e-5 m) and should 

be accounted for in the SDR equation in order 

to obtain more reliable k estimates. 

References 

Toumelin, E., Torres-Verdin, C. and Chen, S., 

(2003): Modeling of multiple echo-time NMR 

measurements for complex pore geometries 

and multiphase saturations. Spe Reservoir 

Evaluation & Engineering, 6(4), 234-243. 



A general model for predicting hydraulic conductivity of unconsolidated material using 

nuclear magnetic resonance 59 

A general model for predicting hydraulic conductivity of unconsolidated 

material using nuclear magnetic resonance 

Raphael Dlugosch 1 , Thomas Günther, Mike Müller-Petke, and Ugur Yaramanci 


1 Raphael.Dlugosch@liag-hannover.de 

The prediction of hydraulic conductivity (K) 

from nuclear magnetic resonance (NMR) 

measurements of the porosity (ϕ) and decay 

time (T) has been performed successfully on 

sandstones. However, in hydrogeological 

applications, unconsolidated material is more 

prevalent. This material generally shows less 

variability in porosity and tortuosity, but a 

larger range of pore sizes compared to 

sandstones. The known (semi-)empiric 

relations to estimate K from ϕ and T (Seevers, 

1966 and Kenyon et al., 1988) have been 

applied to unconsolidated material, but the 

underlying assumptions are not valid for large 

pores. 

We present a new, general model based on 

tube-shaped pores (after Kozeny, 1927 and 

Carman, 1938) that is valid for the whole range 

of laminar flow, i.e., from silt to fine gravel. 

Compared to former models we additionally 

account for bulk water relaxation and all 

diffusion regimes (after Godefroy et al., 2001), 

and thus overcome the commonly applied fastdiffusion 

approximation. Both bulk-water 

relaxation and slow diffusion significantly 

affect the NMR measurements on coarse 

material. By accounting for the slow-diffusion 

case a maximum K can be derived from NMR 

measurements. Additionally, the model 

replaces the empirical factors in known 

relations with (petro-)physical parameters. 

This enables to separate effects caused by 

variations of the material-specific surface 

relaxivity (ρ) from variations of other, e.g., 

temperature-dependent parameters. This 

increases the range where, after calibration by 

flow experiments on similar material, K can be 

predicted reliably. 

A data set measured on glass beads with 

different grain sizes is used for validation. It 

confirms the applicability of the new model 

and allows to evaluate the impact of surface 

relaxivity by comparing longitudinal and 

transversal relaxation. As an outcome we 

expect the model to improve prediction of 

hydraulic conductivity by surface or borehole 

NMR measurements. 

References 

Carman, P. C. (1938). The determination of the 

specific surface of powders. Journal of the Society 

of Chemical Industrialists, 57:225-234. 

Godefroy, S., Korb, J., Fleury, M., and Bryant, R. 

(2001). Surface nuclear magnetic relaxation and 

dynamics of water and oil in macroporous media. 

Physical Review E, 64(2):1-13. 

Kenyon, W., Day, P., Straley, C., and Willemsen, J. 

(1988). A Three-Part Study of NMR Longitudinal 

Relaxation Properties of Water-Saturated 

Sandstones. SPE Formation Evaluation, 3(3):622- 

636. 

Kozeny, J. (1927). Über kapillare Leitung des 

Wassers im Boden. Sitz.Ber. d. Akad. d. Wiss., 

Math.-Nat. Kl. Wien, 36:271-306. 

Seevers, D. (1966). A nuclear magnetic method for 

determining the permeability of sandstones. Society 

of Professional Well Log Analysts Transactions, 

Paper L:1-14. 



Quantitative aquifer system characterization on Borkum island using joint inversion of 

MRS and VES data 60 

Quantitative aquifer system characterization on Borkum island using joint 

inversion of MRS and VES data 

Thomas Günther, Mike Müller-Petke & Raphael Dlugosch 


Thomas.guenther@liag-hannover.de 

On the barrier islands in the North sea fresh 

water lenses exist that are important for water 

supply. Continuous pumping and climate 

changes are factors that affect the development 

of the ground water lense. For predicting the 

long-term behaviour, ground water modelling 

needs to be done on the base of density driven 

flow (Sulzbacher et al., 2012). For the latter, 

reliable lithologic models and the distribution 

of the quantities porosity (�), hydraulic 

conductivity (K) and salinity must be known at 

the catchment scale. 

Geophysical measurements can help to provide 

three-dimensional information since resistivity 

(�) is sensitive to both clay content and 

salinity. However, the interpretation is 

ambiguous and there is no link to hydraulic 

conductivity. The method Nuclear Magnetic 

Resonance (NMR) yields water content and 

decay time. The latter is sensitive to pore-size 

and therefore allows for estimating hydraulic 

conductivity. Since Magnetic Resonance 

Sounding (MRS) needs a resistivity model, a 

joint inversion with a resistivity sounding, e.g. 

Vertical Electrical Sounding (VES) is 

reasonable. As a result, the desired parameters 

can be retrieved from the inverted properties 

(Günther & Müller-Petke, 2012). 

We present a joint inversion scheme based on a 

block inversion for both apparent resistivity 

and the full free induction decay data cube 

(Müller-Petke & Yaramanci, 2010). Coupling 

of the methods is achieved by common layer 

thicknesses. A Levenberg-Marquardt algorithm 

is used to minimize the error-weighted misfit 

of the combined data set in a least-quares 

sense. Moreover, uncertainty measures can be 

derived by a variance analysis. These 

uncertainties are then propagated into 

uncertainties of the target values. 

The method is applied to three soundings at the 

North Sea island of Borkum. The first 

sounding was conducted at a research borehole 

to verify the method by the known lithology. 

As expected the result clearly shows the two 

aquifers, the unsaturated zone and two 

aquitards. The second sounding was done at a 

pumping test location in order to calibrate the 

K-T relation developed by Dlugosch et al. 

(2011) for the local conditions. Results show a 

similar lithology and parameters as the first. 

Finally, a sounding in the flooding area 

demonstrates the superiority of the joint 

inversion over individual inversion. Whereas 

the MRS data can be explained by a three-layer 

model, four layers are needed for VES and five 

layers for the combined model to fit the data. 

The subsurface model shows two aquifers with 

fresher water over salt water each. The very 

good data quality leads to a precise prediction 

of the target parameters. TDS concentration is 

calculated using a modified Archie equation 

that is calibrated using Direct-Push data. 

The method could be further extended to T1 

experiments that yield a less sophisticated link 

to lithology and pore-sizes. Furthermore, either 

2D/3D joint inversion or a coupling to airborne 

electromagnetic data can finally lead to threedimensional 

ground water models. 

References 

Dlugosch, R., Müller-Petke, M., Günther, T. & 

Yaramanci, U. (2011): Extended prediction of 

hydraulic conductivity from NMR measurements 

for coarse material. Ext. Abstr. 17 th EAGE Near 

Surface Geophysics, Leicester (UK). 

Günther, T. & Müller-Petke, M. (2012): Hydraulic 

properties at the North Sea island of Borkum 

derived from joint inversion of magnetic 

resonance and electrical resistivity soundings, 

Hydrol. Earth Syst. Sci. Discuss., 9, 2797-2829, 

doi:10.5194/hessd-9-2797-2012. 

Müller-Petke, M. & Yaramanci, U. (2010): QT- 

Inversion – Comprehensive use of the complete 

surface-NMR dataset, Geophysics, 75, WA199– 

WA209, doi:10.1190/1.3471523, 2010. 

Sulzbacher, H., Wiederhold, H., Siemon, B., Grinat, 

M., Igel, J., Burschil, T., Günther, T., & Hinsby, 

K. (2012): A modelling study of the freshwater 

lens of the North Sea Island of Borkum, Hydrol. 

Earth Syst. Sci. Discuss., 9, 3473–3525, 

doi:10.5194/hessd-9-3473-2012. 



Research and Practice of the Relationship between MRS Inversion Parameters and the 

Water Yield 61 

Research and Practice of the Relationship between MRS Inversion 

Parameters and the Water Yield 

Yao Wang 1 ,Zhenyu Li 2 ,Qiuyu Lv 2 , Haijun Xie 2 ,Lishuang Yan 2 

1. The Hunan KECHUANG Power Engineering Technology Co., Ltd. ChangSha. PRC 

2. China University of Geosciences, 

wangyao2772@gmail.com 

Groundwater engineering has approximately 

150 years of experience. By contrast, the 

geophysical MRS technique is commercially 

available only for last approximately 20 years. 

The method of traditional geophysical find 

water in the aquifer storage and flow property 

evaluation is not enough, hydrogeological 

methods commonly used method like drilling 

wells and pumping tests, are expensive and 

time-consuming.MRS method as the only 

direct detection method for groundwater has an 

advantage compared to traditional geophysical 

techniques and hydrogeological methods. But 

very few people research how to study the 

water yield by MRS inversion parameters, this 

article is about the research and practice of the 

relationship between MRS inversion 

parameters and the water yield. 

According to the MRS practice and borehole 

data in Guangdong, Anhui, Qinghai of the 

University of Geosciences (Wuhan) in recent 

years , to establish contact through the MRS 

parameters and transmissivity, while after 

establish contact between the transmissivity 

and the water yield. This article calculated the 

CT values of the unconsolidated sediment 

aquifers and bedrock aquifers according to 

Guangdong and Anhui data, and obtained the 

empirical formula of the transmissivity T and 

specific capacity q. 

According to the application data of MRS 

method to find water in the Qinghai region, 

this article analyzes the MRS method for the 

detection of the Quaternary unconsolidated 

sediment aquifers and bedrock aquifers depth 

and aquifer thickness, finds that the greater the 

depth of the aquifer and the smaller the 

thickness, the larger the point of measurement 

error. The results show that the MRS method 

detection is accurate. 

The article compares the transmissivity TMRS, 

the specific capacity qMRS, the water yield 

QMRS of MRS with the pumping tests 

(Tpt,qpt,Qpt).The relative errors are within an 

acceptable range, the MRS detection results of 

the calculation method is more accurate. We 

found that the greater the depth of the aquifer, 

the larger of the error. And this relates to the 

increase with depth of MRS method, the lower 

the resolution. 

References 

M.Mejías,J.Plata. General concepts in 

Hydrogeology and Geophysics related to MRS. 

Boletín Geológico y Minero,2007,118,423-440 

J.M.Vouillamoz,J.M.Baltassat,J.F.Girard.Hydrogeo 

logical experience in the use of MRS.Boletín 

Geológico y Minero,2007,118,531-550 

M.W.Lubczynski,J.Roy. Use of MRS for 

hydrogeological system parameterization and 

modeling. Boletín Geológico y 

Minero,2007,118,509-530 

The use of MRS in the determination of hydraulic 

transmissivity:The case of alluvial 

aquifers.JuanL.Plata ,F¨|lixM.Rubi. Journal of 

Applied Geophysics 66(2008)128–139. 



Case studies 



62

Exploiting the phase information: examples from the Netherlands 63 

Exploiting the phase information: examples from the Netherlands 

Jean Roy * and Maciek Lubczynski & 

(*) IGP, Outremont, QC, Canada; (&) ITC, Enschede, The Netherlands 

(*) jeanroy_igp@videotron.ca; (&) Lubczynski@itc.nl 

As early as the first MRS Workshop in Berlin, 

in 1999, observations were made on aquifers 

missed by MRS. Excluding magnetic rocks, 

typically three conditions were simultaneously 

met for such missed aquifers: (1) the data 

inversion was using only the signal amplitude, 

(2) the missed aquifer was below a shallower 

aquifer but still within the nominal detection 

range of the MRS instrument, and (3) the 

missed aquifer was within or below a less 

resistive layer than the shallower aquifer. 

Under such conditions, the NMR signal 

produced by the 2 nd deeper aquifer may have 

such a phase rotation that the amplitude of the 

resultant field has the same shape on the MRS 

sounding as the shape of a single aquifer 

amplitude response. In the Netherlands, the 3rd 

condition corresponds to the presence of a 

clay-rich aquitard between the top and the 

deeper aquifer. In one of the presented cases, 

this is also supplemented by a deeper aquifer 

with higher salinity. 

In Central-Northern Europe, so also in the 

Netherlands, the typical post-glacial 

hydrostratigraphic system is composed of 

unconsolidated deposits forming interchanging 

layers’ systems of permeable aquifers and 

clay-rich aquitards. Such systems are also 

typical in The Netherlands where this study 

was carried out. In the multi-layered aquifer 

systems, often 2 nd or even 3 rd aquifers are 

productive. If less porous or hydraulically 

conductive they still may constitute a valuable 

groundwater reserve less vulnerable to surface 

contamination. Besides, even if affected by 

salinity rejecting their use for exploitation, 

their characterization (parameterization and 

salinity distribution) would still be useful to 

characterize the system vulnerability to the 

salinity expansion under groundwater 

abstraction of the overlying aquifers. 

The deep aquifers overlain by conductive 

aquitards were in the past detected either by: 

(1) a complex kernel scheme (Braun and 

Yaramanci, 2003) or (2) by having selective 

phase components extraction prior to the 

amplitude-only inversion (Roy and 

Lubczynski, 2003). These two solutions had 

disadvantages for the MRS end-user: solution 

(1) was for in-house use only while solution 

(2) required preprocessing the data set prior to 

its inversion. This last solution was done in 

several steps. First up-front modeling of the 

resistivity depth profile was done to select the 

appropriate phase components. Next the 

selected phase components were extracted 

from the field data and two data sets were thus 

generated: the upper target and deeper target 

data sets. These data sets were then processed 

in a normal way with amplitude-only MRS 

data inversion tools of the time (i.e. in the late 

1990s). 

Recently an off-the-shelf MRS data inversion 

tool - Samovar_11 (Legchenko, 2011) – 

became available to MRS end-users. This tool 

has an option to use phase at the inversion step. 

The advantages of using such strategy in terms 

of simplicity, layer discrimination and 

characterization will be illustrated through the 

reprocessing of the MRS surveys of the multilayered 

systems in the Netherlands earlier 

presented by Roy and Lubczynski (2003). 

References 

Braun, M. and Yaramanci, U., 2003, Inversions of 

surface-NMR signals using complex 

kernels; 9 th EEGS-ES Meeting, Prague, 

Aug 31 st -Sept 4, Paper O-049. 

Legchenko, A., 2011, Samovar Software 11x3 

User's Guide, IRD, France. 

Roy, J. and Lubczynski, M., 2003, The case of an 

MRS-elusive second aquifer; Proceedings 

2 nd international MRS workshop, 19-21 

Nov. 2003, Orléans, France, p. 105-108. 



MRS and electrical prospection in the context of weathered peridotite rocks in the South of 

New Caledonia. 64 

MRS and electrical prospection in the context of weathered peridotite rocks 

in the South of New Caledonia. 

Girard 1* J-F., J-M. Baltassat 1 , A. Legchenko 2* A., S. Morlighem 3 , I. Domergue- Schmidt 3 , P. 

Maurizot 4 , J-L. Folio 3 and B. François 1 

1 BRGM, Orléans, France; 2 IRD / LTHE, Grenoble, France; 3 VALE, New Calédonia. 4 BRGM, Nouméa, New 

Caledonia; 

jf.girard@brgm.fr 

In November 2011 and July 2012 were 

conducted geophysical prospections in the 

southern part of New Caledonia. Both 

electrical tomography (ERT) and Magnetic 

Resonance Sounding (MRS) were performed 

to obtain a better understanding of the water 

storage and circulation. The geological context 

is the weathering profile of peridotite rock 

(Maurizot and Vendé-Leclerc, 2009). 

In such environment, the general distribution 

of geology is (from surface to depth), the iron 

cap, laterite (red and yellow), saprolite, 

fractured and then fresh bedrock. The lateritic 

profile is developed over a thickness ranging 

from 20m to 60 m. 

Electrical imagery is a well-established method 

to detect variations in depth and laterally in 

this geological context (Robineau et al., 2007) 

and is routinely used in mining exploration and 

exploitation to estimate the thickness of 

laterite. 

Hydrogeology in this environment is complex 

because water flows in heterogeneous media: 

infiltration trough the iron cap, unsaturated 

zone, fractured bedrock. As a consequence, 

various regimes of hydrological responses are 

observed, from low permeability (laterite) to 

high permeable zones (fractured zone and 

locally “pseudo-karst” behavior). 

MRS as a tool to detect directly water and 

provide insight of higher permeable zone 

sounds attractive in such a context. The sites 

studied are well documented thanks to preexisting 

boreholes logs and hydrogeological 

studies. 

Difficulty to perform MRS there is link to two 

major reasons. First, the rocks present nonnegligible 

magnetic susceptibility. Despite 

surface measurement of the geomagnetic field 

revealed to be relatively homogeneous at the 

loop scale (< 100 nT variation), standard Free 

Induction Decay (FID) MRS measurement 

appeared to be un-practicable (like observed by 

Roy et al., 2008). The average magnetic 

susceptibility is 5 10 -4 SI and it proved to be 

suitable to perform MRS measurement in Spin 

Echo (SE) mode (Roy et al, 2009, Legchenko 

et al., 2010, Vouillamoz et al., 2011). 

The second difficulty is link with the very fine 

structure of laterite, where a large part of water 

is not detectable by MRS like bound water in 

clay. But the high yield zones revealed to 

produce a clear MRS signal in SE mode. 

We present a review of the various ERT and 

MRS responses observed in this context. 

References 






Maurizot P., Vendé-Leclerc M., 2009, Geological 

map of New Caledonia at 1/500 000, 1 st edition, , 

DIMENC, BRGM. 

Robineau B., Join J.L., Beauvais A., Parisot J-C., 

Savin C., Geoelectrical imaging of a thick 

regolith developed on ultramafic rocks : 

groundwater influence. Australian Journal of 

Earth Sciences, 54 (773-781), 2007. 




in the Grenville geological province, Canada: 


Roy J., Legchenko A., Menier J., Chouteau M., 

Bureau M. and Rouleau A. 2009. MRS in spineco 

mode – 2008 tests in the Greenville. 

MRS2009 Workshop, Grenoble, France, 

Expanded Abstracts, 201–206. 

Vouillamoz J-M., A. Legchenko A., Nandagiri, 

Characterizing aquifers when using magnetic 

resonance sounding in a heterogeneous 

geomagnetic field, Near Surface Geophysics, 

2011, 9, 135-144. 



MRS and borehole correlation in Denmark 65 

MRS and borehole correlation in Denmark 

Mette Ryom Nielsen 1 , Tom Feldberg Hagensen 2 , Anatoly Legchenko 3 and Konstantinos 

Chalikakis 4 

1) Rambøll A/S, Aarhus, Denmark, 2) Danish Ministry of the Environment, 3) IRD / LTHE, Grenoble, France, 

4) UMR 1114 EMMAH (UAPV-INRA), Avignon, France 

1) mrn@ramboll.dk, 2) tofha@nst.dk, 3) anatoly.legtchenko@ujf-grenoble.fr, 4) konstantinos.chalikakis@univavignon.fr 

Since 2005 succesfull efforts have been made 

to implement MRS in the portfolio of 

hydrogeophysical services applied in Danish 

surveys (Chalikakis et el., 2008, Chalikakis et 

al., 2009, Ryom Nielsen et al., 2011). Each 

survey is carefully planned according to the 

specific purpose and the optimal combination 

of methods from the portfolio is determined. 

Between 2005 and 2012 approximately 200 

MRS soundings have been performed in the 

framework of more than 30 different surveys 

in Denmark each aiming a specific purpose 

and agenda. Many of the surveys are 

performed as a part of the national Danish 

groundwater mapping. 

In the Danish groundwater mapping large scale 

hydrogeophysical mappings are typically 

performed initially with either SkyTEM or 

CVES. Hereby locations of possible aquifer 

systems are discriminated and borehole 

locations are suggested based on this. To help 

prioritise the most optimal of these borehole 

locations MRS are performed before drilling. 

Subsequently drillings are performed at the 

optimal locations indicated by the MRS 

results. Additional drillings have been 

performed at other MRS locations in order to 

verify the results of the method. 

Besides these new boreholes the national 

Danish borehole database contains more than 

240,000 borehole logs corresponding to an 

average of approximately 5.5 boreholes per 

km 2 . Hence existing boreholes can often be 

found in proximity and used for correlation 

purposes. 

All the available MRS measurements 

performed in Denmark since 2005 until today 

and existing borehole information compose a 

relatively large dataset of approximately 125 

borehole and MRS pairs available for 

correlation. 

The correlation between MRS and boreholes 

are performed with attention to both the 

measured MRS amplitude, the interpreted 

MRS parameters; water content and hydraulic 

conductivity, the borehole log description and 

the electrical resistivity interpreted from 

TDEM soundings at the MRS location. 

In most cases very good correlation is 

observed between MRS results and borehole 

descriptions. These examples will be presented 

along with example of more complicated 

correlations. 

Examples of correlation between MRS and 

boreholes are given for different geological 

environments ranging between Glacial 

Quaternary melt water sediments, Tertiary 

sandy formations and in Cretaceous and 

Palaeocene limestone. 

The borehole and MRS correlations are 

summed up in different cross plots of the MRS 

parameters and the lithological description of 

the aquifer from the borehole log. Clear 

variations of the interpreted hydraulic MRS 

parameters are observed. These variations 

correlate overall well with the expectations of 

the hydraulic variations based on the aquifer 

characteristics. 

References 

Chalikakis, K., Nielsen, M. R., Legchenko, A. 

(2008): MRS applicability for a study of glacial 


Denmark, Journal of Applied Geophysics 66, 

176-187. 

Chalikakis, K., Nielsen, M. R., Legchenko, A., 

Hagensen, T. F. (2009): Investigation of 

Sedimentary aquifers in Denmark using the 

magnetic resonance sounding method (MRS), C. 

R. Geoscience 341, 918–927. 

Ryom Nielsen M., Hagensen T. F., Chalikakis K., 

and Legchenko A. (2011): Comparison of 


Denmark, Near Surface Geophysics, vol. 9, no. 

2, 211-223. 



Implementation of MRS in the Danish National Groundwater management 66 

Implementation of MRS in the Danish National Groundwater management 

Tom Feldberg Hagensen 1 , Mette Ryom Nielsen 2 , Anatoly Legchenko 3 and Konstantinos 

Chalikakis 4 

1) Danish Ministry of the Environment, 2) Rambøll A/S, Aarhus, Denmark, 3) IRD / LTHE, Grenoble, France, 

4) UMR 1114 EMMAH (UAPV-INRA), Avignon, France 

1) tofha@nst.dk, 2) mrn@ramboll.dk, 3) anatoly.legtchenko@ujf-grenoble.fr, 4) konstantinos.chalikakis@univavignon.fr 

In Denmark the watersupply is based on high 

quality ground water where complex and 

expensive purification is not needed. However 

increasing threats to the groundwater ressource 

from urban and agricultural sources forced a 

national protection plan in 1998. 40% of 

Denmark is designated as particularly valuable 

water-abstraction areas in which intensive 

hydrogeological mapping is performed, 

(Thomsen et al, 2004). The National Danish 

groundwater mapping is performed by the 

Ministry of the Environment (NST) as a part of 

the Act of Environmental Goals. 

The hydrogeological mapping has an estimated 

cost of €20 mil. per year and it is financed by a 

surcharge of €0.05 per m 3 on drinking water 

paid by the consumer. 

NST encourage development of methods in 

cooperation with universities and consultancies 

in order to improve quality, speed and cost 

efficiency of the mapping procedures. 

MRS was considered in 2005 and subsequently 

used in the groundwater mapping for the first 

time (Chalikakis et al. 2008). Data and results 

carefully acquired from 2006 proved MRS to 

be efficient under Danish conditions (Chalikakis 

et al. 2009; Ryom Nielsen et al. 2011). 

By 2009 MRS campaigns were improved in 

frequency and the amount of data increased, 

hence official implementation of MRS in the 

national groundwater mapping was required. 

Co-operation agreement between NST, 

consultancies and universities was established. 

The objective was implementation of MRS in 

the national groundwater mapping comparable 

to implementation of other geophysical 

methods. This requires open minded cooperation 

between experienced hands-on field 

work, developers of hardware, acquisition 

software, data interpretation software and 

database developers. 

The implementation process will be presented 

and the task included: 

� Tests on different geology in Denmark, 

verified with boreholes and pumping tests. 

� Expansion of the national geophysical 

database for both field data and inversion. 

� Requirements specifikation and national 

guide for data acquisition and interpretation. 

� Course for project leaders in groundwater 

mapping. 

� MRS theme days for sharing experiences. 

� Establishment of a national test site for MRS 

In 2010 MRS has been included in the EU 

Framework agreement used for contracts with 

consultant engineering firms in the national 

groundwater mapping. 

Until june 2012 more than 30 projects in the 

national groundwater mapping have included 

MRS. From single site measurements with 

focus on well site location to input into 3D 

geological models and groundwater modelling. 

References 

Thomsen, R., Søndergaard, V. H., Sørensen, K. I. 

(2004): Hydrogeological mapping as a basis for 

establishing site-specific groundwater protection 

zones in Denmark. Hydrogeology Journal, 12, p 

550-562. 

Chalikakis, K., Nielsen, M. R., Legchenko, A. 

(2008): MRS applicability for a study of glacial 


Denmark, Journal of Applied Geophysics 66, 

176-187. 

Chalikakis, K., Nielsen, M. R., Legchenko, A., 

Hagensen, T. F. (2009): Investigation of 

Sedimentary aquifers in Denmark using the 

magnetic resonance sounding method (MRS), C. 

R. Geoscience 341, 918–927. 

Ryom Nielsen M., Hagensen T. F., Chalikakis K., 

and Legchenko A. (2011): Comparison of 


Denmark, Near Surface Geophysics, vol. 9, no. 

2, 211-223. 



Feasibility study of the MRS monitoring in a 3D hydrogeological structure: aquifer 

recharge from a pond in the Sahel (Niger) 67 

Feasibility study of the MRS monitoring in a 3D hydrogeological structure: 

aquifer recharge from a pond in the Sahel (Niger) 

M. Boucher 1* , G. Favreau 2 , A. Legchenko 1 

1 IRD / LTHE, Grenoble, France; 2 IRD / HSM, Montpellier, France. Marie.Boucher@ird.fr 

Currently, MRS method is often used for 

characterizing spatial distribution of 

hydrodynamic parameters, but rarely for 

monitoring temporal changes in groundwater 

content (e.g. Descloitres et al. 2008). This 

issue is particularly challenging in 3D context 

of rapid changes in aquifer storage. 

In the Sahel, groundwater recharge is mostly 

an indirect process and mainly occurs through 

temporary ponds. An estimate of seasonal 

changes in water storage in the vicinity of 

ponds is thus important for quantifying 

groundwater recharge. The aim of this study is 

to assess the ability of the MRS method to 

better quantify the temporal variations of 

groundwater storage near temporary pond in 

sedimentary porous aquifers. 

In SW Niger, the Wankama catchment (2 km 2 , 

60 km east of Niamey, Niger’s capital) was 

selected for field implementation. This site has 

got the benefit from a long-term hydrological 

monitoring (Cappelaere et al. 2009) including 

rainfall measurements, pond water level 

records and 4 piezometric surveys positioned 

perpendicularly to the pond axis. In this area, 

the aquifer is unconfined and composed of 

sandstone. The pond is rapidly filled up by rain 

events during the monsoon (June to October), 

then water infiltrates under the pond and 

contributes to the aquifer recharge. The 

piezometric gradient is close to 0.1‰ during 

the late dry season (May) and forms a dome of 

increasing amplitude during the rain season to 

reach its maximum in September. 

NumisPlus© equipment was used with edgeto-edge 

or overlapping eight-shape coincident 

loops with 2 squares of 50 meters side each. 

The spatial distribution of water content was 

mapped with 21 soundings performed during 

the dry season when the pond was drying up 

and piezometric levels were almost horizontal. 

Data were inverted in 3D with Samovar 

software (Legchenko et al. 2011). 

The influence of water table fluctuations on the 

MRS signal was modeled taking into account 

the heterogeneity of the porosity evidenced by 

the MRS mapping. The groundwater level 

showed rise up to ~5.7 m at the edge of the 

pond during the wet season. According to 

numerical modeling, temporal changes in the 

MRS signal are expected to be greater than the 

measurement uncertainty that is particularly 

high during the monsoon due to frequent 

thunder storm events. Modeling results were 

confirmed by MRS monitoring carried out 

between 2008 and 2010: soundings on two 

loop positions were repeated 6 and 7 times in 

contrasted hydrologic conditions. Significant 

variations of MRS signal were only observed 

at the position the closest to the pond and for 

extreme hydrologic event (four days after an 

exceptional rainfall event of ~100 mm). 

However the 3D modeling showed that the 

variation of piezometric level could not 

completely explain variations in the MRS 

signal. In particular, the variation of the water 

level in the pond was shown to bring a 

significant influence on the MRS signal 

(~20 nV). 

MRS quantification of temporal natural 

changes of the groundwater storage in the 

aquifer formation was shown possible only for 

significant variations of the water volume. The 

quantification of minor variations is limited by 

the sensitivity of the MRS measurements. 

References 

Cappelaere B., Descroix L., Lebel T. et al. 2009. 

The AMMA-Catch experiment in the cultivated 

Sahelian area of south-west Niger - Investigating 

water cycle response to a fluctuating climate and 

changing environment. Journal of Hydrology 

375 (1-2): 34-51. 

Descloitres M., Ruiz L., Sekhar M. et al. 2008. 

Characterization of seasonal local recharge using 

Electrical Resistivity Tomography and Magnetic 

Resonance Sounding. Hydrological Processes 

22: 384-394. 

Legchenko A., Descloitres M., Vincent C. et al. 

2011. Three-dimensional magnetic resonance 

imaging for groundwater. New Journal of 

Physics 13: 025022. doi:10.1088/1367- 

2630/13/2/025022. 



Research on Gushing Disaster Detection in Tunnel with Magnetic Resonance Sounding 68 

Research on Gushing Disaster Detection in Tunnel with Magnetic 

Resonance Sounding 

Qin Shengwu1,2, Lin Jun1,Jiang Chuandong1, Wang Yingji1 

1.College of Instrument Science & Electrical Engineering, Jilin University, Changchun 130026, China 

2.College of Construction Engineering, Jilin University, Changchun 130026, China 

qinsw@jlu.edu.cn 

Gushing disaster often happen during tunnel 

construction, and normal water detection 

methods are almost indirect methods. Magnetic 

Resonance Sounding(MRS) is a direct 

underground water geophysics detection 

method, which can efficiently detect and 

quantify underground water. 

In the usual surface based measurements, with 

horizontal loop on the ground, the exploration 

depth approximate to the side length of single 

turn loop (maximum 150m). Because of the 

restriction of tunnel space, the multi-turn coil 

can be used to insure the sufficient detection 

distance. So, we can use MRS instruments 

with small multi-turn coil to detect 

waterbearing ahead of tunnel operation. 

For the subsuface based measurements in 

tunnels, where the loop is non-horizontal, the 

geometry can be described in an effective 

inclination that can be expressed in terms of 

the Earth magnetic inclination, declination, and 

the orientation of the tunnel operation. 

Forward simulation bas been carried out. The 

simulation model is a 100m side lengh cube, 

whose resistivity is 500 Ω� m . the Earth 

magnetic inclination, declination are 

respectively 60 degree, 5 degree, and the 

orientation of the tunnel operation is 124 

degree. The coil is 4.5m×8m with 8 turns, and 

excitation frequency is 2325 HZ. Forward 

simulation results indicate that 1m thickness 

target waterbearing fractures, located 30m 

ahead of tunnel operation can produce 5nV 

signal, which can be received by JLMRS 

instrument. 

Moreover, through forward simulation, 

analysising the relationship of Earth magnetic 

inclination, declination, and the orientation of 

the tunnel operation, the optimal coil lay plan 

is proposed. 

To test the feasibility of the tunnel usage of 

MRS, a typical gushing water tunnel tests has 

been performed. This tunnel is a highway 

road , whose diameter is 12m and the rock are 

mostly basalt with fractures. When we test, the 

tunnel operation was gushing water on the 

speed of 8~10m 3 /h. We used JLMRS 

instrument with 8 turns 4.5m×8m coil placed 

against the tunnel operation to detect the water. 

Through time domain analysis, the received 

signals obviously decline with time, which 

indicate that the signals are MRS signals 

produced by water ahead of tunnel operation. 

The signal amplitude E0 is about 10~20nV, 

and S/N ratio is 0.9983. Noise cancellation 

(weighted stack, adaptive notch filter 50HZ, 

lowpass filter 10HZ)has been processed. After 

noise cancellation S/N ratio can reach 3.5288, 

which can be used to data inversion. 

After data inversion with smooth inversion and 

block inversion, we get the water content 

distuibution plot within 30m distance away 

from tunnel operation. The result shows that 

water content within 10m distance is higher 

than 10m~30m.That is to say, it is gushing 

water now, but it will stop gushing after 10m, 

which coincide with actual situation. 

From the forward simulation, tunnel test, data 

time domain analysis, and comparison with 

actual situation, we draw a conclusion that 

MRS detection with multi-turn coil can be 

used in tunnels. 

References 

Reinhard Meyer, Michael van Schoor, Jan 

Greben.(2007): Development of and Tests with 

the NMR[C].10th SAGA Biennial Technical 

Meeting and Exhibition Technique to Detect 

Water Bearing Fractures. 

J.M. Greben, R. Meyer, Z. Kimmie. (2008):The 

underground application of Magnetic Resonance 

Soundings. Journal of Applied Geophysics. 



NMR Logging: A tool for quantifying effective porosity and hydraulic conductivity within 

the Murray Darling Basin of Australia 69 

NMR Logging: A tool for quantifying effective porosity and hydraulic 

conductivity within the Murray Darling Basin of Australia 

Jared D. Abraham, 

jdabraha@usgs.gov, United States Geological Survey, Denver, Colorado 

Kok Piang Tan, 

KokPiang.Tan@ga.gov.au, Geoscience Australia, Canberra, Australia 

Ken Lawrie, 

Ken.Lawrie@ga.gov.au, Geoscience Australia, Canberra, Australia 

Ross S. Brodie, 

Ross.Brodie2@ga.gov.au, Geoscience Australia, Canberra, Australia 

Jon Clarke, 

Jon.Clarke@ga.gov.au, Geoscience Australia, Canberra, Australia 

Gerhard Schoning, 

Gerhard.Schoning@ga.gov.au, Geoscience Australia, Canberra, Australia 

Within Australia, and the world, understanding 

groundwater resources and their management 

are growing in importance to society as 

groundwater resources are stressed by drought 

and continued development. To minimize 

conflicts, new tools and techniques need to be 

applied to support knowledge-based decisions 

and management. The critical and challenging 

measurements in characterizing aquifers 

include effective porosity and hydraulic 

conductivity. Typically, values for effective 

porosity and hydraulic conductivity are derived 

by lithological comparisons with published 

data; direct measurements of hydraulic 

conductivity acquired by a few constant head 

aquifer tests or slug tests; and expensive and 

time consuming laboratory measurements of 

cores which can be biased by sampling and the 

difficulty of making measurements on 

unconsolidated materials. Aquifer tests are 

considered to be the best method to gather 

information on hydraulic conductivity but are 

rare because of cost and difficult logistics. 

Also they are unique in design and 

interpretation from site to site. Nuclear 

Magnetic Resonance (NMR) can provide a 

direct measurement of the presence of water in 

the pore space of aquifer materials. Detection 

and direct measurement is possible due to the 

nuclear magnetization of the hydrogen 

(protons) in the water. These measurements are 

the basis of the familiar MRI (magnetic 

resonance imaging) in medical applications. 

NMR is also widely used in logging 

applications within the petroleum industry. 

Within the Murray Darling drainage NMR data 

were acquired in 26 boreholes. Effective 

porosity values were derived directly from the 

NMR data, and hydraulic conductivity values 

were calculated using empirical relationships 

calibrated and verified with few laboratory 

permeameter and aquifer tests. NMR provided 

measurements of the effective porosity and 

hydraulic conductivity at a resolution not 

possible using traditional methods. Unlike 

aquifer tests, NMR logs are not unique in 

design and are applied in similar fashion from 

borehole to borehole providing a standard way 

of measuring hydraulic properties. When the 

hydraulic properties from the NMR are 

integrated with hydrogeological interpretations 

of airborne electromagnetic data large areas of 

the Murray Darling Basin can be characterized. 

This provides a much more robust method for 

conceptualizing groundwater models then 

simply using previously published data for 

assigning effective porosity and hydraulic 

conductivity. Borehole NMR allows superior, 

rapid measurements of the complexities of 

aquifers within the Murray Darling Basin when 

compared with the traditional methods. 

References 

Lawrie, K.C., Brodie R.S., Dillon, P., Tan, K.P., 

Gibson, D., Magee, J., Clarke, J.D.A., 

Somerville, P., Gow, L., Halas, L., Apps, H.E., 

Page, D., Vanderzalm, J., Abraham, J., Hostetler, 

S., Christensen, N.B., Miotlinski, K., Brodie, 

R.C., Smith, M. and Schoning, G., 2012. 

BHMAR Project: Assessment of Conjunctive 

Water Supply Options to Enhance the 

Drought Security of Broken Hill, Regional 

Communities and Industries- Summary 

Report. Geoscience Australia Record 

2012/15. 213 p. 



MRS study of water content variations in the unsaturated zone of a karst aquifer (southern 

France) 70 

MRS study of water content variations in the unsaturated zone of a karst 

aquifer (southern France) 

Mazzilli N.* 1 , Boucher M. 2 , Chalikakis K. 3 , Legchenko A. 2 , Jourde H. 1 , Carriere S. 3 , 

Guyard H. 2 , Chevallier A. 2 

1 

UMR 5569 HSM, Université Montpellier 2 CC MSE, 34095 Montpellier cedex 5, France 

2 

IRD/LTHE, Grenoble, France 

3 

UMR 1114 EMMAH (UAPV/INRA), Avignon, France 

*mazzilli@msem.univ-montp2.fr 

In the mediteranean bassin, groundwater in 

karst aquifers is a vital but also highly 

vulnerable resource. The unsaturated zone of 

karst plays a key role in the recharge and 

contaminant attenuation processes but 

unsaturated zone properties assessment 

remains mostly qualitative. 

Presented study aims to assess the potential of 

the Magnetic Resonance Sounding method 

(MRS) applied to the characterisation of the 

unsaturated zone of karst systems. MRS 

method was initially developed for 

characterizing saturated aquifers, and few 

applications in unsaturated zone have been 

performed up to now. Hence the issues 

addressed are: (i) does water storage within the 

unsaturated zone of karst yield measurable 

MRS signal ? if so, (ii) can we evidence either 

a temporal or a spatial variability of the MRS 

response ? and (iii) can we relate MRS 

response variability to observed unsaturated 

zone characteristics ? 

A total of 21 sites have been selected for the 

MRS investigations in dolomite and limestone 

formations on the Larzac plateau and the Lez 

recharge area (southern France), based on the 

two following criteria: (i) diversity and spatial 

representativity of the hydrogeological and 

geomorphological setting, and (ii) favorable 

ambient electromagnetic noise conditions. The 

temporal variability of the MRS signal was 

investigated by repeating soundings on 7 of 

these sites where high water storage variations 

were expected. During our study we used the 

NUMIS plus and NUMIS lite instruments with a 

80×80 m 2 square loop or eight-shaped loops 

with 40 m size each square. 

The average signal-to-noise ratio for the MRS 

measurements is equal to 4, which confirms 

the applicability of the MRS method for the 

investigation of the unsaturated zone of karst. 

Usually, the detection of MRS signal in 

unsaturated zone is limited by the short 

relaxation time T2* that cannot be detected due 

to the instrumental dead time. In the case of 

karst unsaturated zone, the possibility to record 

signal is explained by a low magnetic 

susceptibility of limestone and dolomites that 

allowed T2 * not to be affected by natural 

heterogeneities in magnetic field. 

As regards the spatial variability, the raw MRS 

responses clearly distinguish between the 

investigated formations: the maximum values 

of signal amplitude and T2* are associated with 

ruiniform dolomite (40 to 80nV and up to 250 

ms respectively) whereas minimum signal 

amplitudes and T2* (

Investigating hydraulic properties of a glacial sand deposit in the north of Sweden 71 

Investigating hydraulic properties of a glacial sand deposit in the north of 

Sweden 

Perttu 1* N., A. Legchenko 2 

1 Luleå University of Technology, Sweden; 2 IRD / LTHE, Grenoble, France. 

nils.perttu@ltu.se 

The city of Luleå is located about 1000 km 

north of Stockholm, Sweden, with 73 000 

inhabitants. The city is dependent on artificial 

groundwater, i.e. the cleaning of surface water 

through infiltration of a natural sand formation. 

Due to the recent establishment of Facebook, 

this alone demands 10% of the drinking water 

currently produced and an increasing 

population inevitably lead to a need to increase 

the drinking water production. In order to 

extend existing water supply the local 

authorities initiated a hydrogeophysical study 

aiming to improve the knowledge of the lateral 

and vertical extension of the aquifer together 

with its hydraulic properties. In the 

investigated area the granite basement is 

covered by a glacial deposit of a few tens of 

meters, consisting of medium to coarse sand 

with interlacing layers of clay and silt. The 

aquifer borders to areas of till with poorer 

aquifer potential. The magnetic susceptibility 

of the sand and till varies between 10 -3 to 10 -2 

SI. 

In this study, the Magnetic Resonance 

Sounding (MRS) method has been used 

(Legchenko et al, 2004). However, due to the 

presence of magnetic materials, standard MRS 

measurements, based on measuring the free 

induction decay signal (FID), were inefficient 

(Roy et al., 2008). Thus, the more intricate 

MRS spin echo (SE) mode was used 

(Legchenko et al, 2010; Vouillamoz et al, 

2011). The water supply plant with running 

pumping installations and corresponding 

power lines is located close to an industrial 

zone and consequently the level of industrial 

noise was very high. The measurements were 

made with 20×20 m 2 and 50×50 m 2 figureeight 

loops (Trushkin et al., 1995) using notchfiltering 

(Legchenko and Valla, 2003), and a 

stacking number between 200 and 600. 

No FID signals were observed in any of the 

nine soundings made. The amplitude of the SE 

signal varied between 20 to 120 with a T2 * 

about 30 ms. The water content derived from 

inversion ranged from 10 to 30% with the 

relaxation time T2 between 260 and 560 ms, 

thus showing a clear heterogeneity of the 

glacial deposit. 

MRS results were compared with numerous 

boreholes (lithology and hydraulic properties) 

with good correspondence. Some boreholes 

located at a distance of 50 m (which is 

comparable with MRS loop size) show fivefold 

variation in the hydraulic conductivity derived 

from pumping tests thus pointing on a 3D 

formation. Under these conditions we consider 

that 1D MRS results were sufficiently 

accurate. 

We have shown that MRS SE allowed getting 

reliable information of the hydraulic properties 

of the subsurface that could not have been 

obtained using other geophysical methods. 

References 

Legchenko A., and P. Valla (2003): Removal of 

power line harmonics from proton magnetic 

resonance measurements. Journal of Applied 


Legchenko A., J-M. Baltassat, A. Bobachev, C. 

Martin, H. Robin, and J-M. Vouillamoz (2004): 

Magnetic resonance sounding applied to aquifer 

characterization. Journal of Ground Water, 42, 

363-373. 






Trushkin D.V., O.A. Shushakov, and A.V. 

Legchenko (1995): Surface NMR applied to an 

electroconductive medium: Geophysical 

Prospecting, 43, 623-633. 




in the Grenville geological province, Canada. 


Vouillamoz J-M., A. Legchenko A., Nandagiri 

(2011): Characterizing aquifers when using 

magnetic resonance sounding in a heterogeneous 

geomagnetic field, Near Surface Geophysics, 9, 

135-144. 



Estmating regional groundwater reserve in a clayey sandstone aquifer of Cambodia. 72 

Estmating regional groundwater reserve in a clayey sandstone aquifer of 

Cambodia. 

Vouillamoz a , J.-M.; Sophoeun b , P.; Bruyere c , O.; Caron a , D.; and Arnout c , L. 

a IRD, UMR LTHE; b Cambodian Red Croos; c French Red Cross 

Jean-Michel.Vouillamoz@ird.fr 

Climate change and rapid population growth in 

Asia will probably impact all water sources. 

Since most of the Earth's liquid fresh water is 

groundwater, its potential buffer role will be a 

key issue to support adaptation strategies. The 

buffer behavior of aquifer is controlled by 

several factors including the groundwater 

reserve (i.e. the amount of groundwater 

actually stored in the rock reservoir). 

Although the knowledge of groundwater 

reserve is a key isssue, it is usually quantified 

based on poor dataset (see for example 

MacDonald et al., 2011 for Africa). Moreover, 

common tools used by hydrogeologists for 

quantyfying groundwater reserve (i.e. 

hydraulic tests and groundwater modelling) 

consume a numerous set of data, a lot of 

money and time, and thus they are rarely used 

for routine works in developing countries. 

Nowadays, the potential of magnetic resonance 

sounding (MRS) for complementing the 

hydrogeological toolbox is well known. 

However, relationships between the field scale 

MRS results and hydrogeological storagerelated 

properties have not been well 

established yet (Vouillamoz et al., 2005; 

Boucher et al., 2009). 

We started a study in a clayey sandstone 

environment of Northern Cambodia in 2010. 

Our main objective is to quantify the water 

ressources at a regional scale (about 2 000 

km²) for establishing appropriate practices for 

the development of irrigated paddy field. In 

this paper, we present the methodology we 

developed and the results we obtained for 

quantyfying the groundwater reserve of the 

targeted region. 

We first present the result of a comparison 

between MRS records (i.e. water content and 

decay rate of FID signal) and both specific 

yield calculated from pumping tests and 

effective porosity calculated from tracer tests. 

Based on these results obtained at 9 sites, we 

adapt an approach used in the oil industry for 

differencing gravitational water from capillary 

water and from bound water, based on the 

MRS decay time parameter (among other 

Dunn et al., 2002). For checking the validity of 

our so-named MRS apparent cutoff time 

approach (MRS-ACT), we compare MRS 

signal recorded just before pumping (i.e. in a 

fully saturated reservoir) with signal recorded 

while pumping (i.e. gravitational water 

removed) at a single location. Then, we use our 

MRS-ACT approach for estimating 

groundwater reserve at a regional scale from 

47 MRS squatered over the area. 

We conclude that we are able to estimate the 

specific yield with an average error of 23%, 

which is far less than the previous published 

results. Then, we found that the groundwater 

reserve of the surveyed aquifer is ranging 

between 120 and 200 liters/m² of surface area 

for 50% of the sites. If we had considered that 

MRS water content is a rough estimate of the 

specific yield, then the groundwater reserve 

would have been over-estimated from 13 to 

55%. 

References 

Boucher, M., Favreau, G., Vouillamoz, J.M., 

Nazoumou, Y. and A., L., 2009. Estimating 

specific yield and transmissivity with Magnetic 

Resonance Sounding in an unconfined sandstone 

aquifer. Hydrogeology Journal, ISSN 1431- 

2174. 

Dunn, K.J., Bergman, D.J, Latorraca, G.A., 2002. 

Nuclear magnetic resonance petrophysical and 

logging applications. Elsevier Science Ltd, 293 

pp. 

MacDonald, A.M., Bonsor, H.C., Calow, R.C., 

Taylor, G.R., Lapworth, D.J., Maurice, L., 

Tucker, J. and O Dochartaigh, B.E., 2011. 

Groundwater resilience to climate change in 

Africa. OR/11/031, British Geological Survey 

Open Report. 

Vouillamoz, J.M., Descloitres, M., Toe, G. and 

Legchenko, A., 2005. Characterization of 

crystalline basement aquifers with MRS : 

comparison with boreholes and pumping tests 

data in Burkina Faso. Near Surface Geophysics, 

3: 205-213. 



Application of underground magnetic resonance sounding on advanced detection waterinduced 

disaster in 3D structure 73 

Application of underground magnetic resonance sounding on advanced 

detection water-induced disaster in 3D structure 

Lin Jun, Jiang Chuandong, Lin Tingting 


ttlin@jlu.edu.cn; willianjcd@yahoo.com.cn; 

Introduction 

Water-induced disasters, such as tunnel 

water-gush, mine water-inrush, fatal goafwater 

accident, have happened around world in 

recent years. Nondestructive detection methods 

(TSP, GPR and BEAM) are applied for waterbursting 

detection. However, misjudgment 

often occurs due to the multiple potential 

interpretations of exploration results. Magnetic 

resonance sounding (MRS) method is then 

conceived as it is particularly relevant to 

groundwater investigations. Whereas, 

performing MRS in underground condition 

(UMRS) presents considerable challenges for 

three main reasons: 1) the size of the loop is 

severely limited by the tunnel dimensions. 2) 

Calculation of the exciting magnetic field 

when the antenna was rotated by an arbitrary 

angle. 3) In the whole space domain, UMRS 

signal could be significantly affected by 

interference water behind the heading face. 

To solve the above problems, on the theoretical 

basis of surface MRS method, underground 

MRS of whole space is modeled within this 

paper. The advance detection distance could be 

extended by using multi-turn transmiter and 

receiver antenna. Meanwhile, by introducing 

the concept of rotation coefficient matrix, the 

vertical component of exciting field with 

arbitrary direction of geomagnetic field and 

antenna can effortlessly calculated. 

Forward problem 

For UMRS forward problem, hydraulic 

conductivity fault is generalized to a plate with 

widths 1 m to 4 m. The large karst cave is 

approximated as a sphere with radius of 5 m to 

15 m. In regard to rather complicated karst 

cave system, the combination of plates and 

spheres is modeled. The UMRS responses of 

the three water-bearing structures have been 

numerical simulated in 3D. 

Our results suggest that, by using 10 turn 

or 100 turn coincident antenna with the size of 

6 m or 2 m, the advanced detection distance 

can be reached to 30 m assuming that the 

receiving sensitivity of MRS instrument is 

5nV. Additionally, series of numerical 

modelling exercises suggest that the optimal 

coupling of the angles could be achieved when 

the normal orientation of the antenna is 

paralleled to direction of geomagnetic field. 

This fact make feasible that, either with the 

smaller pulse moment to detect the same depth 

of water, or with the same pulse moment to get 

the maximum MRS signal amplitude which 

provide a higher sensitivity to groundwater 

distribution. The interference water will bring 

disturbance to the observed UMRS signals, but 

the influence is negligible with extended 

distance in the back of the heading face. 

3D inversion 

According to the advanced detection 

distance and the influence range of interference 

water, the inversion space is optimized to a 

reasonable zone with 3000 subdivision units in 

front of heading face. Numerical simulations 

of 3D inversion in regard to hydraulic 

conductivity fault, karst cave and complicated 

karst system are presented to confirm the 

feasibility of UMRS method. 

Conclusion 

In summary, the present numerical study 

proposed in this paper will promote the 

development of UMRS equipment and provide 

technical support for early warning of waterinduced 

disasters. 

References 

Greben, J. M., Meyer R., Kimmie Z, 2011. The 

underground application of Magnetic Resonance 

Soundings. Journal of Applied Geophysics 75, 

220-226 

Girard, J. F., Legchenko, A., Boucher, M., et al, 

2008. Numerical study of the variations of 

magnetic resonance signals caused by surface 

slope. Journal of Applied Geophysics 66, 94- 

103. 

Hertrich, M., 2008. Imaging of ground water with 

nuclear magnetic resonance. Progress in Nuclear 

Magnetic Resonance Spectroscopy 53, 227–248 

. 



Surface NMR applied to determining aquifer properties in the Central Platte River, central 

Nebraska 74 

Surface NMR applied to determining aquifer properties in the Central 

Platte River, central Nebraska 

Jared D. Abraham 

US Geological Survey Denver, Colorado, jdabraha@usgs.gov 

Trevor P. Irons 

US Geological Survey Denver, Colorado, tirons@usgs.gov 

James C. Cannia 

US Geological Survey Mitchell, Nebraska, jcannia@usgs.gov 

Christopher M. Hobza 

US Geological Survey Lincoln, Nebraska, chobza@usgs.gov 

Gregory V. Steel 

US Geological Survey Lincoln, Nebraska, gvsteele@usgs.gov 

Duane D. Woodward 

Centeral Platte Natrual Resource District, woodward@cpnrd.org 

Surface nuclear magnetic resonance (SNMR) 

is a non-invasive geophysical method that 

measures a signal directly related to the 

amount of water in the subsurface. This allows 

for low-cost quantitative estimates of hydraulic 

parameters. In practice though, additional 

factors influence the signal complicating 

interpretation. The U.S. Geological Survey, in 

cooperation with the Nebraska Environmental 

Trust and the Central Platte Natural Resources 

District, evaluated whether hydraulic 

parameters derived from SNMR data could 

provide valuable input into groundwater 

models used for evaluating water management 

practices. Two calibration sites in Dawson 

County, Nebraska were chosen based on 

previous detailed hydrogeologic and 

geophysical investigations. At both sites, T2* 

free induction decay SNMR data were 

collected, and derived parameters were 

compared with results from four constantdischarge 

aquifer tests previously conducted at 

these same sites. Additionally, borehole 

electromagnetic induction flow meter data 

were analyzed as a less expensive substitute 

for traditional aquifer tests. Flow meter data 

allow increased resolution of the hydraulic 

properties than the constant-discharge aquifer 

tests. An innovative SNMR modeling and 

inversion method was used that incorporates 

electrical conductivity and magnetic field 

inhomogeneity effects, which had a significant 

impact on the data, on the T2* free induction 

decay data. After calibrating the SNMR 

inversions at the two calibration sites, SNMR 

derived parameters were compared with 

historical aquifer tests at other locations within 

the Central Platte Natural Resources District. 

This served as a blind test for the SNMR. The 

SNMR derived aquifer parameters were in 

agreement with the aquifer tests in most cases. 

In some cases, the previously performed 

aquifer tests were not designed to fully 

characterize the aquifer, and the SNMR was 

able to provide missing data. This allows the 

calibrated SNMR parameters to be applied 

throughout the general hydrogeological 

environment of the Central Platte Natural 

Resources District. The factors that influenced 

the success of the SNMR included cultural and 

natural noise; conductive sediments; and the 

quality of the hydrogeological calibration data. 

One other issue is the lack of quantifiable 

uncertainty in many of the hydrogeological 

calibration data. 

In favorable locations SNMR is able to provide 

valuable non-invasive information about 

aquifer parameters. This allows for an 

improved spatial sampling of the critical 

aquifers within the Central Platte Natural 

Resources District. Using this data within 

groundwater models provides a useful tool for 

groundwater managers in Nebraska. 

References 

Irons, T.P., Hobza, C.M., Steele, G.V., Abraham, 

J.D., Cannia, J.C., Woodward, D.D., (2012): 

Quantification of aquifer properties using 

nuclear magnetic resonance in the Platte River 

valley, central Nebraska using a novel inversion 

method, USGS Scientific Investigations Report 

2012, 125 p. 



Case studies of the MRS method in various geological backgrounds 75 

Case studies of the MRS method in various geological backgrounds 

Jean BERNARD, Orlando LEITE, Fabrice VERMEERSCH 

IRIS Instruments 

iris@iris-instruments.com 

Since a few years, the Magnetic Resonance 

Sounding method has become more and more 

popular all around the world for groundwater 

investigations. 

The interpretation of the MRS measurements 

permits to estimate the water content (porosity) 

and the permeability of each layer at depth. 

These parameters are useful to determine the 

prospects of a groundwater reservoir before 

drilling and to make a prediction of the yield of 

water which can be obtained, after calibration 

with existing holes in the area of the survey. 

The integration of MRS among other more 

traditional geophysical methods (DC 

resistivity, TDEM, …) will be the key point of 

its success in the long term, taking into account 

the advantages and the limitations and the cost 

of all these methods. The optimization of the 

budgets of the surveys is indeed an important 

factor of the projects aiming at providing water 

to population, cattle, agriculture, mining or 

other industrial activities. 

Field examples of MRS data will be given, 

obtained in various continents including Asia 

and Africa, with different geological contexts 

and with various EM noise, magnetic latitude, 

loop geometries conditions; also, when 

available, in comparison with borehole results. 

References 

F. Vermeersch, J Bernard, O. Leite (2003): 

Comparison of various loop geometries in 

Magnetic Resonance Soundings on the Pyla sand 

dune (France), 2 nd MRS Workshop, Orleans 

J. Bernard (2006): Instruments and field work to 

measure a Magnetic Resonance Sounding with 

NUMIS equipment, 3 rd MRS Workshop, Madrid 

J. Bernard (2006): Application use of the Proton 

Magnetic Resonance method (MRS) for 

groundwater investigations in various geological 

environments, AGU, San Francisco 

J. Bernard (2012): Application use of the Magnetic 

Resonance Sounding method for groundwater 

exploration, ICEEG, Changsha 



Joint use of MRS and TDEM for characterizing groundwater recharge in the Lake Chad 

basin 76 

Joint use of MRS and TDEM for characterizing groundwater recharge in 

the Lake Chad basin 

Boucher 1* M., G. Favreau 2 , M. Descloitres 1 , K. Chalikakis 3 , A. Legchenko 1 , M. Ibrahim 2 , M. Le Coz 2 , 

A.M. Moussa 4 

1 IRD / LTHE, Grenoble, France; 2 IRD, UM2 / HSM, Montpellier, France; 3 UAPV / EMMAH, Avignon, France; 

4 Ministère de l’Hydraulique et de l’Environnement, Zinder, Niger. Marie.boucher@ird.fr 

Dramatic changes in surface area of Lake 

Chad, semiarid Africa, are known to have 

occurred during the Holocene and have largely 

impacted the aquifer recharge at the basin 

scale. Yet, little is known on the pattern of the 

aquifer hydrodynamics, thus affecting the 

reliability of groundwater modeling (Leduc et 

al. 2000). The objective of our study is to 

evaluate the contribution of the joint use of 

MRS and TDEM for investigating aquifer 

characteristics below and close to the Lake. 

Two field-surveys were carried out in the 

northwestern part of Lake Chad Basin: 1) in 

2008, a detailed 12-km-long profile (117 

TDEM and 11 MR soundings) was carried out 

across the valley of the Komadugu river, one 

of the 3 tributaries of Lake Chad; 2) 12 TDEM 

and MR soundings were performed at regional 

scale (~10 4 km 2 ) in May 2010 (a period when 

the Lake is mostly dry). The MRS 

NumisPlus® equipment was used with square 

loops of 100 m side length to reach the 

maximum depth of investigation. High natural 

electromagnetic noise was observed during 

afternoon and night, limiting the time window 

for data acquisition (~from 6:00 until 14:00 

local time). MRS data were interpreted using 

Samovar software with 3 alternative inversion 

schemes 1) smooth automatic inversion; 2) 

blocky inversion by letting all parameters free 

and assuming a one-uniform-layer distribution 

of water content; 3) blocky inversion by fixing 

the geometry of aquifer according to TDEM 

results. For TDEM acquisition, the light (2 Kg) 

Tem-Fast 48 device (AEMR technology,) was 

used with coincident Tx/Rx loop of 50×50 m 2 , 

providing 100-m-deep investigation. Data were 

then inverted with the Tem-Res software. 

The aquifer permeability (KMRS) was computed 

using the standard empirical relationship: 

� �2 K MRS � Cp �� 

MRS T where θMRS is the MRS 

1 

water content, T1 is the relaxation time, and Cp 

is an empirical pre-factor. In our study, Cp was 

calibrated using results of two short (12h) 

pumping tests. A relatively high value of Cp 

(~2.10 -7 ) in comparison with previous studies 

(e.g. Vouillamoz et al. 2007) was obtained that 

may be due to the presence of a thin (~8 m) 

coarse sandy layer usually targeted for 

boreholes screen location at depth of ~35 m 

below the soil surface and hidden for MRS by 

a thicker, shallower and less permeable layer 

of fine to clayey sands. 

MRS results revealed a distribution of aquifer 

hydrodynamic properties that depends on the 

distance to surface waters: (1) High θMRS (10- 

35%) and KMRS (10 -3 to 10 -2 m/s) values are 

evidenced below present-day Lake Chad. (2) 

Below the former clayey deposits of the 

Megalake Chad, lower θMRS (8-13%) and KMRS 

(10 -4 to 10 -3 m/s) values were estimated. These 

low values suggest limited aquifer fluxes, in 

accordance with the occurrence of paleogroundwater 

(determined by isotopes) below 

the clayey plain. (3) Intermediate and 

homogenous hydraulic properties (θMRS and 

KMRS values in the ranges of 16 to 25% and 

1.10 -3 to 3.10 -3 m/s, respectively) were found 

below the Komadugu valley, filled with 

coarser fluvial sediments. TDEM allowed 

estimating accurately the depth of the Pliocene 

clayey formation (~2 Ω.m) which is supposed 

to be the aquifer substratum. The variations of 

resistivity inside aquifer are probably related to 

both presence of a variable amount of clay and 

variable water salinity (electrical conductivity 

of water varying from 0.2 mS/m in the 

Komadougou valley to 5 mS/m bellow the 

Lake Chad). The combination of MRS and 

TDEM methods proved to be an important tool 

to identify groundwater recharge patterns in 

this poorly documented area. 

References 

Leduc C, Sabljak S, Taupin JD et al. 2000 Recharge of 

the Quaternary water table in the northwestern Lake 

Chad basin (southeastern Niger) estimated from 

isotopes. C.R. Acad. Sci., IIa 330: 355-361. 

Vouillamoz JM, Baltassat JM, Girard JF et al. 2007 

Hydrogeological experience in the use of MRS. 

Boletín Geológico y Minero 118: 531-550. 



Assessment of the use of surface NMR to detect internal erosion and piping in earthen 

embankments 77 

Assessment of the use of surface NMR to detect internal erosion and piping 

in earthen embankments 

Trevor Irons 1 , Meghan C. Quinn 2 , Jason R. McKenna 2 , and Yaoguo Li 1 

1 Colorado School of Mines, 2 U.S. Army Engineer Research & Development Center 

tirons@mines.edu, Meghan.C.Quinn@usace.army.mil, Jason.R.McKenna@usace.army.mil, 

ygli@mines.edu 

The US Army Corps’ National Inventory of 

Dams (2012) currently identifies 26,642 dams 

with either high or significant hazard potential. 

This represents over 30% of the structures in 

the database. Almost all of the dams in the 

database are of earthen construction and many 

are old and few details are known about their 

construction. Levees present a similar hazard. 

There are many failure modes of dams and 

levees: internal erosion and piping, 

overtopping, undercutting, and dry-side 

erosion. Of these failure modes, internal 

erosion and piping is one most difficult to 

assess, as it cannot be directly observed. 

Geophysical methods provide a means to 

assess these structures noninvasively. As there 

is often little information about the 

construction of these older earthen dams, many 

geophysical methods that rely on indirect 

relationships between material properties and 

water content can be unreliable in this 

application. For instance, there may not be a 

large electrical resistivity change associated 

with internal erosion events in every dam. 

Surface NMR (sNMR) is unique in its ability 

to directly detect water, and also estimate the 

pore size and hydraulic permeability of media. 

For this reason sNMR could be an invaluable 

tool for non-invasively assessing internal 

erosion in dams and levees. 

We present sNMR and subsurface seepage 

forward modelling results from several earthen 

embankment scenarios. A homogeneous 

earthen embankment is loaded with a high 

level of water until seepage is detected. We 

then modelled a series of scenarios of piping 

developing in the embankment. 

Typical erosional piping patterns start at the 

toe of the embankment and progress back 

towards the head. As the piping progresses, 

significant drop in the phreatic surface across 

the embankment develops, and presents a 

target for sNMR mapping. 

We assess the deployment of coincident and 

separated sNMR transmitter and receivers 

under changing field conditions and static 

magnetic field orientations. The significant 

topography of the earthen embankment 

requires special care. We address this by 

integrating around an arbitrary current source 

and calculating the magnetic fields generated 

by finite ungrounded electric dipoles along the 

current path. The optimal use of separated or 

coincident transmitters and receivers is 

affected by the static magnetic field 

orientation, as well as the geometry of the 

earthen embankment. We demonstrate that 

under favourable, but plausible, field 

conditions, sNMR can provide valuable 

information in the assessment of earthen 

embankment internal erosion. 

References 

US Army Corps of Engineers (2012). National 

inventory of dams. http://nid.usace.army.mil/. 



The Applications of MRS for detection of Groundwater-induced disasters , in China 78 

The Applications of MRS for detection of Groundwater-induced disasters , 

in China 

Lin Jun, Duan Qingming, Fan Tie-hu 

College of Instrumentation and Electrical Engineering, Jilin University, Changchun 130021, China 

Lin_jun@jlu.edu.cn; fth@jlu.edu.cn 

Groundwater is one of the most important and 

indispensable natural resources to human 

beings either in industies or daily life. 

however it sometimes leads to terrible 

catastrophes , such as dam leakage, tunnel 

gushing, water-impacted landslide, seawater 

intrusion, karst collapse, groundwater 

pollution, and coalmine goaf-water. 

Magnetic Resonance Sounding (MRS), which 

is widely used as the most effective and direct 

approach for groundwater investigations, , has 

also been used for detecting the water-induced 

disasters .As it has within certain limits been 

proved to promot the technical supports in 

preventing losses of water disater that MRS 

and other geophysical methods are efficiently 

integrated. The discussions of the detection 

methods with MRS as core technique for their 

each features of the specific water-induced 

disasters are summarized in this paper. The 

high-resolution 2D MRS technique has been 

developed for the survey of dike and dam 

leakage, the 2D MRS-TEM device and MRS- 

TEM joint inversion are applied to the 

extraction of water body boundary as an valid 

solution to karst collapse and mine goaf-water , 

and to the determination of salt-fresh water 

interface of sealine while solving seawater 

intrusion. 2D MRS and TEM joint detection 

for seawater intrusion was carried out 

tentatively in Liaodong bay, and the interface 

between saline and fresh water in the transition 

zone can be infered by the analysis of what the 

interpretation results show. The same kind of 

joint detection with some little pointed 

alternations in detail was also performed in 

Shanxi, China, among the all 13 survey 

lines(192 survey points) 16 water-rich regions 

were ranged by the actual survey data, which is 

confirmed consistent with the engineering 

geology. On the basis of investigating the 

properties of key parameter T2* closely 

related to the porosity of the aquifer, a stability 

evaluation of side slopes with different 

inclinations and conditions of moisture content 

by MRS with coils non-horizontally set. Filed 

experiment of dam leakage detection 

performed on Chuijiajie Dam in Liaoning 

,China, proves the MRS method for dam 

leakage be feasible and effective, and basic 

conclusions are reached on three leakage 

points and two infiltration areas at each 

corresponding depth respectively inside the 

dam body. Not only is a brandnew and 

productive method presented by introducing 

MRS technique into the water-induced disaster 

exploration, but the safety of the people's lives 

and property is earnestly guaranteed. 

References 

Abragam A. The Principles of Nuclear Magnetism 

[M]. London: Oxford University, 1961:648. 

Guillen A, Legchenko A. Application of Linear 

Programming Techniques to the Inversion of 

Proton Magnetic Resonance Measurements for 

Water Prospecting from the Surface [J]. Journal 

of Applied Geophysics, 2002, 50(1-2):149-162. 

Legchenko A V, Semenov A G, Shirov M D. 

Apparatus for Measuring the Parameters of 

Water-Bearing Underground Levers (in 

Russian): USSR, 1540515 [P], 1991.2.5. 

Legchenko A, Valla P. A Review of the Basic 

Principles for Proton Magnetic Resonance 

Sounding Measurements [J]. Journal of Applied 

Geophysics, 2002, 50(1-2):3-19. 

Roy J, Lubczynski M. The Magnetic Resonance 

Sounding Technique and its Use for 

Groundwater Investigations [J]. Hydrogeology 

Journal, 2003, 11(4): 455–465. 

Schirov M, Legchenko A, Creer G. New Direct 

Non-Invasive Groundwater Detection 

Technology for Australia [J]. Exploration 

Geophysics, 1991, 22(2): 333–338. 

Varian R H. Ground Liquid Prospecting Method 

and Apparatus: US, 3019383 [P], 1962.1.30. 

Weichman P B, Lavely E M, Ritzwoller M H. 

Theory of Surface Nuclear Magnetic Resonance 

with Applications to Geophysical Imaging 

Problems [J]. Physical Review E, 2000, 62 (1, 

Part B): 1290–1312. 

Yaramanci U, Lange G, Knödel K. Surface NMR 

within a Geophysical Study of an Aquifer at 

Haldensleben (Germany) [J]. Geophysical 

Prospecting, 1999, 47(6): 923–943. 



Application of surface-NMR to study unfrozen sediments below lakes in permafrost 

regions 79 

Application of surface-NMR to study unfrozen sediments below lakes in 

permafrost regions 

Andrew Parsekian 1 , Jan O. Walbrecker 1 , Mike Muller-Petke 2 , Guido Grosse 3 , Kristina 

Keating 4 , Lin Liu 1 , Benjamin Jones 5 and Rosemary Knight 1 

1 Stanford University, Department of Geophysics, Stanford, CA, USA 


3 University of Alaska, Geophyiscal Institute, Fairbanks, AK, USA 

4 Rutgers University, Department of Earth and Environmental Sciences, Newark, NJ, USA 

5 Alaska Science Center, U.S. Geological Survey, Anchorage, AK 

parsekia@stanford.edu 

Lakes in permafrost landscapes are often 

attributed to thawing of sediments and the 

subsequent pooling of water on the surface 

(Lachenbruch 1962). Over time, and given 

sufficient depth of the "thermokarst" lake, such 

that it exceeds winter ice growth, the sediment 

also thaws resulting in a volume of unfrozen 

material that may extend many tens of meters 

below the surface with a large fraction of 

liquid water known as a thaw bulb. Due to 

microbial methanogenisis in the thaw bulb, 

thermokarst lakes have been identified as an 

important source of methane to the atmosphere 

with contributions to global climate change 

(Walter et al., 2007). Determining the spatial 

extent of unfrozen sediment is important to 

estimating the methane production potential of 

thermokarst lakes; however, measurements of 

thaw bulb thickness by direct (i.e. probes and 

boreholes) and geophysical methods (e.g. DC 

resistivity, GPR) have met with limited success 

thus far mostly due to limitations in depth 

penetration and differentation between frozen 

and unfrozen sediment. To understand 

hydrology in discontinuous permafrost regions 

it is also important to determine if thaw bulbs 

are hydraulically connected to deep, regional 

groundwater (open) or if they are bounded by 

permafrost on all sides (closed). We have 

identified surface-NMR as a tool for 

investigating thaw bulb sediments due to the 

large volume of water present in thaw bulb 

sediments and the appropriate depth of 

investigation in excess of 100 m. To 

demonstrate the ability of surface-NMR to 

make the desired measurements of water 

content and thaw bulb depth, we conducted 

surface-NMR surveys on thermokarst lakes 

near Fairbanks, Alaska, USA. Measurements 

were made on frozen lakes during the winter to 

facilitate deployment of the instrument over 

the deepest portions of the lakes. Figure-eight 

transmitting/receiving loop configurations 

were used in conjunction with reference loops 

in a multi-channel configuration to compensate 

for electromagnetic noise originating from 

nearby power lines in the Fairbanks area. The 

data were inverted using a 1D blocky inversion 

that simultaneously fit the NMR amplitude and 

T2 * decay time data. Four layers were 

sufficient to obtain good fit to the data. From 

top to bottom these layers correspond to lake 

ice, lake water, thaw bulb sediments and 

permafrost. At a 6 m deep lake, the thaw bulb 

was deeper than the maximum sensitive depth 

of the surface-NMR measurement (>23 m) 

given the figure-eight configuration. At a 

smaller, 1.2 m deep lake, a thaw bulb depth of 

4 m below the lake surface was observed. For 

comparison, we made measurements using 

square loops at a terrestrial permafrost location 

with borehole control for ground truth 

purposes. The measurement at this location 

indicated unfrozen sediments below 30 m and 

also suggests sensitivity to the low water 

content (θ

Usage of Magnetic Resonance Sounding (MRS) for attaining hydrogeological profiles 

(Havelland, Brandenburg) 80 

Usage of Magnetic Resonance Sounding (MRS) for attaining 

hydrogeological profiles (Havelland, Brandenburg) 

K. Seibertz 1 , T. Günther 2 , S. Costabel 3 

1 Martin-Luther-University Halle/Wittenberg 

2 Leibniz Institute for Applied Geophysics (LIAG), Hannover 


klodwig.seibertz@student.uni-halle.de 

The knowledge about aquifer properties in the 

near-surface underground is of great 

importance for different types of questions, 

e.g. for groundwater modelling. Therefore 

knowledge about the hydraulic conductivity, 

water content and of course the location of 

aquifers has to be gathered. Often this 

information is taken from drilling cores or 

groundwater observation-wells, which are 

expensive and not always applicable. 

The main goal of this work was to show that 

the feasibility of magnetic resonance sounding 

(MRS) in the vicinity of settlements in 

geologically less prospected areas is given and 

furthermore that it could be used as 

inexpensive and fast method to increase the 

density of the hydro-/geological information of 

the underground in addition to existing 

drillings. 

Therefore, MRS was applied in Brädikow, a 

village in Havelland/Brandenburg. The 

geological and hydro-geological informations 

where gathered from a hydro-geological 

profile created by LBGR (Landesamt für 

Bergbau, Geologie und Rohstoffe 

Brandenburg). MRS was applied along the 

hydro-geological profile and finally the data of 

four successful soundings were analysed. The 

collected data was analysed for water content, 

hydraulic conductivity, as well as for position 

of the aquifers. Hydraulic conductivity was 

calculated from T2* decay times using the 

empiric equation by Seevers (1966). The 

needed calibration factor (CS) is generally set 

to values in the range of 30-326*10 -4 m/s 2 

(Mohnke & Yaramanci 2008) but in this case it 

was set to 15*10 -4 m/s 2 , a value obtained by 

Dlugosch et al. (2011) for the closely located 

test-site Nauen. The collected data was 

combined to a hydro-geological profile, which 

was compared to the LBGR profile. To 

overcome the problems of noise from the near 

settlement, different noise cancellation 

methods were applied. 

In fact, the comparison of the hydrogeological 

profile with the MRS results shows a good up 

to very good accordance to the vertical 

distributions of the two aquifers within the 

surveying area. The results allow a more 

detailed reinterpretation of the formerly, by 

LBGR, published data. 

We conclude that MRS nowadays is an 

inexpensive and fast applicable technology of 

non-invasive geophysics that can be used in 

addition to conventional drilling to increase the 

knowledge about near-surface underground 

properties. 

References 


Yaramanci, U. (2011): Extended prediction of 

hydraulic conductivity from NMR measurements 

for coarse material. Ext. Abstr. EAGE Near 

Surface Conference, Leicester. 

Mohnke, O., Yaramanci, U. (2008): Pore size 

distributions and hydraulic conductivities of 

rocks derived from Magnetic Resonance 

Sounding relaxation data using multi-exponential 

decay time inversion. In : Journal of Applied 

Geophysics 66, 73-81. 

Seevers, D. (1966): A nuclear magnetic method for 

determining the permeability of sandstones. 

Conference of Society of professional Well Log 

Analysts. 

Seibertz, K. (2011): Möglichkeiten zur Aquiferabbildung 

mit Magnet Resonanz Sondierung 

(MRS) im Vergleich zum hydrogeologischen 

Schnitt Brädikow – Witzker See (in German). 

BSc thesis, Kiel University. 



Calibration MRS Hydrodynamic Parameters Measurements from Pumping Tests in Inner- 

Mongollia of China 81 

Calibration MRS Hydrodynamic Parameters Measurements from Pumping 

Tests in Inner-Mongollia of China 

LIN Jun 1 , SUN Shu-Qin 1 *, ZHAO Yi-Ping 2 , DUAN Qing-Ming 1 , LI Hai-Sheng 2 

1,Lab. of Geo-Exploration and Instrumentation Ministry of Education of China, College of Instrumentation and 

Electrical Engineering Jilin University, Changchun, China, 130061; 2. Grad uate School of Department of 

Water Resources, Inne r-Mongolia 010000, China 

Lin_jun@jlu.edu.cn, sunsq@jlu.edu.cn 

Introduction Magnetic resonance soundings 

(MRS) have been performed to characterize 

the aquifer and measure groundwater in Inner- 

Mongolia of China. An extensive geological 

study using MRS equipment was performed 

during 2001 to 2005. By comparing MRS 

measurements with pumping tests, we could 

establish an empirical relationship between 

MRS and hydrodynamic parameters, and 

establish a methodology for MRS 

characterization over potential groundwater 

exploration drilling sites in Inner-Mongolia. 

Methodology A methodological study for 

calculating the hydraulic conductivity and 

transmissivity from the automatic inversion 

process provided by the Samovar software, 

study the relationship between the hydraulic 

conductivity and the pumping capacity, there 

are different equations to calculate the 

hydraulic conductivity from pump capacity for 

phreatic water and confined water, establish an 

empirical model to calculate the hydraulic 

conductivity of the several boreholes for 

phreatic water and confined water. 

Field test A field measurement using the 

NUMISplus system developed by IRIS 

company was carried out in Wulateqi of innermongolia. 

There are two large zones of 

fracture in the test area, the purpose of this 

measurement is to explore the aquifer depth 

and thickness at the both sides of zones of 

fracture. More than one hundred MRS tests 

were carried out, the MRS inversion results 

including the aquifer depth and thickness, 

water content , relaxation time constant, the 

hydraulic conductivity and the transmissivity 

were analyzed. 

Summary and Conclusions Based on MRS 

measurements and borehole data, an empirical 

relationship was established between MRS 

results and pumping test transmissivity. The 

methodology derived from this study was 

successfully applied to new potential drilling 

sites for drinking water supply in this terrain. 

References 

Juan L. Plata, Félix M. Rubio, The use of MRS in 

the determination of hydraulic transmissivity: 

The case of alluvial aquifers, Journal of Applied 

Geophysics. 2008 (66):128–139 

Wiete Schoenfelder, Hans-Reinhard Gläser, et al., 

Two-dimensional NMR relaxometry study of 

pore space characteristics of carbonate rocks 

from a Permian aquifer Journal of Applied 

Geophysics. 2008 (65): 21–29 

Balzarini, M., Brancolini, A., et al., Permeability 

estimation from NMR 

diffusionmeasurements in reservoir rocks.Magnetic 

Resonance Imaging. 1998, 16:601–603. 

Banavar, J.R., Schartz, L.M., Magnetic resonance 

as a probe of permeability in porous media. 

Physical Review Letters. 1987.58 (14):1411- 

1414. 

Boucher M., Favreau G., et al., Estimating specific 

yield and transmissivity with magnetic resonance 

sounding in an unconfined sandston aquifer 

(Niger), Hydrogeology Journal. 2009, 

doi:10.1007/s10040-009-0447-x. 

Edmilson Helton Rios, Paulo Frederico de Oliveira 

Ramos, Modeling rock permeability from NMR 

relaxation data by PLS regression, Journal of 

Applied Geophysics. 2011 (75):631-637 

Yaramanci, U., Lange, G., et al., 2002. Aquifer 

characterization using surface NMR jointly with 

other geophysical techniques at the Nauen/Berlin 

test site. Journal of Applied Geophysics 2002. 

(50):47-65 



Characteristics and Examples of MRS Signals in Good Conductive Areas 82 

Characteristics and Examples of MRS Signals in Good Conductive Areas 

Kai Wang, Zhenyu Li, Yao Wang, Hao Liu, Peng Wang 


841651351@qq.com 

MRS is only geophysical method which is 

direct to find water in the world at present. So 

MRS is widely used for groundwater 

exploration and aquifer characterization. Since 

this is an electromagnetic method, the 

excitation magnetic field depends on the 

resistivity of the subsurface. Therefore, the 

resistivity has to be taken into account in the 

application. 

This paper mainly discusses the effect of 

resistivity to MRS signals. In MRS signals, 

resistivity brings φ0 , which is decided by E0. 

So the effect of resistivity can be discussed by 

E0-q curves and φ0 -q curves. 

We do the forward to get the φ0 –q curves and 

E0-q curves. And we focus on the trend of 

phase with the formation resistivity. We select 

the symbol of its extreme point, and that is the 

outlier. The results show that the phase 

changes with variations of the formation 

resistivity. The lower the resistivity is, the 

greater the phase value is. 

Then we do an example of MRS signals in 

good conductive areas. The project is done in 

saline-alkali soil. The salinity of soil is big, so 

the resistivity is small. And phases are large 

negative value. It can prove the resistivity of 

the earth is low. Consequently, the inversion 

obtained by general methods is affected. We 

should notice it. 

At last, we think it significant. The lack of 

conventional inversion method can be found 

by understanding the impact of the formation 

resistivity to MRS signal, which can guide us 

to improve the inversion method. 

References 

Chengyong Ying. (1998): Forward calculation of 

the NMR signals (D).CUG. 

Yimin Chen. (2010): Relationship between phase of 

NMR signals and conductivity of stratum 

(D).CUG. 

Yuling Pan, Changda Zhang. (2000): Theories and 

methods of finding water by SNMR(M).CUG. 



The Experimental Study of MRS Method in Plateau Permafrost Region 83 

The Experimental Study of MRS Method in Plateau Permafrost Region 

Jiagang Zhang, Zhenyu Li, Yunhao Guan, Yuanjie Li, Jianwei Pan 


zhang_jiagang@126.com 

Magnetic Resonance Sounding (MRS) is the 

only geophysical method currently which is 

specially designed for direct water detection, 

and this new technique has wide applications 

in many fields in recent years. However, due to 

only 30-year development history, the 

researches of this method mainly focus on 

common environments, while the application 

in high-pressure environments, such as plateau 

permafrost region, is excluded. The spatial 

distribution of permafrost zone is of 

importance to the study of the existence of 

terrigenous gas hydrate, the exploration of 

which becomes an international hotspot 

academic issue recently, with the increasing 

demand for energy sources globally. 

Several works have been done regarding on 

MRS applied in permafrost zone. Firstly, the 

NMR signals of permafrost samples in the lab 

would be acquired and analysed so that the 

change laws of parameters of signals can be 

drawn. And then, experimental work has been 

carried out in the field to acquire NMR signals 

in permafrost zone, thereby determining 

connotations of signals curses according to the 

results in the lab. Meanwhile, the comparison 

with drilling results in the same positions 

shows that two groups keep consistent 

basically, especially the determination of the 

lower limit of permafrost, so it can be verified 

the feasibility that Magnetic Resonance 

Sounding could be applied in plateau 

permafrost region. Consequently, large-scale 

applications in some experimental zone have 

been conducted to deduce the profile of the 

lower limit of permafrost in this area. At the 

same time, several issues has been discussed, 

including the work mode of MRS applied in 

this special environment, the problem about 

detection depth, as well as the way to eliminate 

noise interference. 

References 

Changda Zhang, Zhenyu Li, Yuling Pan. (2011): 

Development of MR Sounding Technology. 

Chinese Journal of Engineering Geophysics, 8 

(3): 314-322. 

Hongtao Zhang, Yonghai Zhu. (2011): Survey and 

research on gas hydrate in permafrost region of 

China. Geological Bulletin of China, 30 (12): 

1809-1815. 

Sloan, E. Dendy. (2003): Fundamental principles 

and application of natural gas hydrates [J]. 

Nature, 426 (20): 353-359. 

Yaramanci U. (2004): New technologies in ground 

water exploration. Surface Nuclear Magnctic 

Resonance, 2(2): 109-120. 

Youhai Zhu, Yongqin Zhang. (2009): Gas Hydrates 

in the Qilian Mountain Permafrost, Qinghai, 

Northwest China. Acta Geologica Sinica, 83 

(11): 1762-1771.

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