download pdf - Institut für Umweltphysik - Ruprecht-Karls-Universität ...

More documents

Recommendations

Info

168 CHAPTER 6. FORSCHUNGSSTELLE “RADIOMETRIE” 6.1.8 Trace element mapping of speleothems Andrea Schröder-Ritzrau (Participating scientists: Yann Lahaye, Stefan Niggemann, Detlev Richter, Dana Riechelmann, Denis Scholz , Christoph Spötl) Abstract In recent years, numerous speleothem based proxy studies have advanced understanding of annual to decadal scale climate variability. The Research Group DAPHNE is establishing a routine for speleothem LA-ICP-MS measurements in cooperation with Prof. G. Brey, head of the Mineralogical <strong>Institut</strong>e, University of Frankfurt. Figure 6.9: Ten point running mean Strontium content for two parallel profiles with a distance of 300 µm. The profiles show the same general trend. But, variations in small scale cyclicity are visible. Background Trace elements (e.g. Mg, Ba, Sr, P) cycles in speleothems may provide information on past rainfall intensity [Johnson et al. , 2006; Treble et al. , 2003, e.g.]. The DAPHNE group is establishing a routine for speleothem analysis with LA-ICP-MS in cooperation with the Mineralogical <strong>Institut</strong>e in Frankfurt, Germany. Methods and results A 213nm Nd:YAG laser ablation system (UP213 from NewWave) has been coupled to an ICP-MS (Element 2 from Thermo Electron Cooperation). Measurements are performed versus the NIST 610 glass standard and data are normalized to the calcium carbonate content of the speleothem. This synthetic glass standard has been used as an external standard of reference. The calcium content of the sample has also been monitored for the correction related to matrix effect and for the calculation of the trace element concentrations. First results of trace element analysis on a Holocene stalagmite from the Bunker Cave, Iserlohn, North West Germany, are shown. The upper 28 mm of the stalagmite were investigated and correspond to the last 2000 years. Mg and Sr contents of the stalagmite are between 150 and 900ppm and 14 and 42 ppm, respectively. Despite the relatively high noise in the data a general trend to rising Sr values from 25 mm to 20mm with maximum values between 18 to 12 mm is depicted. In the upper 12mm of the stalagmite Sr values are low with three visible excursion to higher values. Generally, a superimposed, small scale cyclicity is visible. However, the chronology is still tentative. Hence, we are not yet able to calculate growth rates and interpret cyclic variations in trace element content. Outlook/Future work The method will be optimized. Trace element contents of additional samples from Grotta di Ernesto, Italy, Bunker Cave, Germany and other caves will be investigated. The results will be interpreted in terms of climate variability. Funding FG DAPHNE (DFG)
6.1. FORSCHUNGSSTELLE “RADIOMETRIE” 169 6.1.9 U-series dating and paleoclimatic interpretation of the stable isotope profile of stalagmite ER76 from Grotta di Ernesto, Italy Denis Scholz (Participating scientists: Christoph Spötl (Innsbruck), Silvia Frisia (Trento), Andrea Borsato (Trento), Jens Fohlmeister) Abstract Stalagmite ER76 from Grotta di Ernesto, Italy, was precisely dated by TIMS Th/Udating. The age-depth-model was constructed using a Bayesian approach to improve the dating uncertainty and applying a mixed effect regression model. Furthermore, high-resolution stable oxygen and carbon isotope profiles were determined. A g e [k y r] 1 0 9 8 7 6 5 4 3 2 1 A g e -d e p th m o d e l (H e e g a a rd e t a l., 2 0 0 5 ) 9 5 % c o n fid e n c e lim its N e w U -s e rie s a g e s U -s e rie s a g e s (M c D e rm o tt e t a l., 1 9 9 9 ) 0 0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 D is ta n c e fro m to p [m m ] Figure 6.10: Final age-depth-model calculated for stalagmite ER76 Background Stalagmite ER76 from Grotta di Ernesto, Italy, was precisely dated by TIMS Th/U-dating. The age-depth-model was constructed using a Bayesian approach to improve the dating uncertainty and applying a mixed effect regression model. Furthermore, high-resolution stable oxygen and carbon isotope profiles were determined. Methods and results Nine TIMS U-series ages as well as high-resolution stable isotope profiles on stalagmite ER76 from Grotta di Ernesto, Italy, were determined. Due to its low 238 U (20- 40 ng/g) content which is typical for stalagmites from Grotta di Ernesto, U-series dating of ER76 is rather difficult. Nevertheless, we were able to determine a 230 Th/U-age of 2.27 0.08 kyr in the youngest part, at 30 mm distance from top (dft). However, due to the low U content, the error bars of some data points overlap significantly. By application of a Bayesian approach which takes into account both the results of the U-series dating and the stratigraphic sequence of the individual samples the uncertainty of some data points could be reduced substantially. We suggest to generally apply this Bayesian approach when the individual data point errors overlap. Overall, 13 data points, nine measured in Heidelberg and four by McDermott et al. [1999], were used to construct the final age-depth relationship for ER76. The age model and its uncertainty (see Fig. 6.10) was estimated using a mixed-effect regression model [Heegaard et al. , 2005]. Based on the new age model, ER76 exhibits a rather constant growth rate of approximately 0.05 mm/yr between 8.5 and 2 kyr. It was actively growing when it was collected, and Frisia et al. [2003] have shown that ER76 exhibits annual laminae in the period between 1650 and 1995 AD. The thickness of these annual laminae lies between 0.02 and 0.1 mm. In combination with the new age model obtained by U-series dating this shows that there must be a substantial hiatus between 2 and 0.5 kyr in ER76. Oxygen and carbon stable isotope profiles were measured at the University of Innsbruck at a resolution of 0.1 mm between 0 and 8 mm dft and 0.25 mm below 8 mm dft. Outlook/Future work An earlier study [Mc- Dermott et al. , 1999] revealed that ER76 recorded several Holocene warm/dry and cold/wet phases, respectively. Because the resolution in that study was approximately 2 mm, the new profiles have a ten times higher resolution which should enable to detect even rapid climate events. Funding DFG Forschergruppe 668: ”Datierte Speläotheme: Archive der Paläoumwelt” Main publication Vollweiler et al. [2006], Scholz & Mangini [2006], Scholz & Mangini [accepted for publication], Mangini et al. [accepted for publication]
Page 1:
Institut für Umweltphysik und Arbe
Page 4 and 5:
4 CONTENTS 2.4.10 Satellite monitor
Page 6 and 7:
6 CONTENTS
Page 9:
Atmosphere and Remote Sensing 2.1 T
Page 12 and 13:
12 CHAPTER 2. ATMOSPHERE AND REMOTE
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 47 and 48:
2.3. RADIATIVE TRANSFER 47 2.3 Radi
Page 49 and 50:
2.3. RADIATIVE TRANSFER 49 Future w
Page 51 and 52:
2.3. RADIATIVE TRANSFER 51 2.3.2 Fi
Page 53:
2.3. RADIATIVE TRANSFER 53 Referenc
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 73 and 74:
2.5. MARHAL - MODELING OF MARINE AN
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
2.6. CARBON CYCLE GROUP 81 2.6 Carb
Page 83 and 84:
2.6. CARBON CYCLE GROUP 83 • Radi
Page 85 and 86:
2.6. CARBON CYCLE GROUP 85 2.6.2 In
Page 87 and 88:
2.6. CARBON CYCLE GROUP 87 2.6.4 In
Page 89:
2.6. CARBON CYCLE GROUP 89 Referenc
Page 93 and 94:
Overview We study the whole range o
Page 95 and 96:
3.1. SOIL PHYSICS 95 Main methods M
Page 97 and 98:
3.1. SOIL PHYSICS 97 3.1.1 Unstable
Page 99 and 100:
3.1. SOIL PHYSICS 99 3.1.3 Physical
Page 101 and 102:
3.1. SOIL PHYSICS 101 3.1.5 Install
Page 103 and 104:
3.1. SOIL PHYSICS 103 3.1.7 Simulat
Page 105 and 106:
3.2. ICE AND CLIMATE 105 3.2 Ice an
Page 107 and 108:
3.2. ICE AND CLIMATE 107 Funding
Page 109 and 110:
3.2. ICE AND CLIMATE 109 3.2.2 Clim
Page 111 and 112:
3.2. ICE AND CLIMATE 111 3.2.4 Prog
Page 113:
3.2. ICE AND CLIMATE 113 Weller, R.
Page 117 and 118: Overview Werner Aeschbach-Hertig Su
Page 119 and 120: 4.1. GROUNDWATER AND PALEOCLIMATE 1
Page 129: 4.1. GROUNDWATER AND PALEOCLIMATE 1
Page 132 and 133: 132 CHAPTER 4. AQUATIC SYSTEMS tran
Page 134 and 135: 134 CHAPTER 4. AQUATIC SYSTEMS 4.2.
Page 137: Small-Scale Air-Sea Interaction 5.1
Page 140 and 141: 140 CHAPTER 5. SMALL-SCALE AIR-SEA
Page 157 and 158: 6.0. FORSCHUNGSSTELLE “RADIOMETRI
Page 167: 6.1. FORSCHUNGSSTELLE “RADIOMETRI
Page 177: Bibliography 177
Page 180 and 181: 180 CHAPTER 7. BIBLIOGRAPHY Butz, A
Page 182 and 183: 182 CHAPTER 7. BIBLIOGRAPHY Leigh,
Page 184 and 185: 184 CHAPTER 7. BIBLIOGRAPHY Wang, P
Page 186 and 187: 186 CHAPTER 7. BIBLIOGRAPHY Kühl,
Page 189: 7.3. PHD THESES 189 PhD Theses Boss
Page 193: 7.5. INVITED TALKS 193 Invited Talk
show all

download pdf - Institut für Umweltphysik - Ruprecht-Karls-Universität ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?