Geophysical data acquisition - OGS

Istituto Nazionale
di Oceanografia e di Geofisica Sperimentale - OGS
GEOPHYSICS
OF THE
LITHOSPHERE
DEPARTMENT
Director: Giuliano BRANCOLINI
2 0 0 0
A N N U A L R E P O R T
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About OGS
The Istituto Nazionale di Oceanografia e di Geofisica Sperimentale -
OGS (formerly Osservatorio Geofisico Sperimentale di Trieste)
is a research institute financed by the Italian Ministry of Universities
and Research. Its function is research in geology, geophysics and
oceanography. More specific tasks are: crustal studies; the search for
oil, gas and minerals; earthquake seismology; environmental
geophysics; hydrogeology; hydrodynamics and ecology of the seas
and oceans.
These activities are carried out by the three Departments of
Geophysics of the Lithosphere, Oceanography, and Seismology, which
employ 56 researchers, 19 senior technicians and 63 technicians.
Although established in 1949, the origin of OGS can be dated back
to 1841, when the Osservatorio Meteorologico was founded at Trieste.
The institution publishes the results of its studies, exploration, and
investigations, and preserves for study and reference the geophysical
data collected by the r/v OGS-Explora during the seven Antarctic
campaigns since 1988, together with the historical archives of the
Trieste seismographic station.
OGS is concerned with transferring the results of its research
activities to industry, and it is open to cooperation with scientists
from academic and research institutions, as well as to partnership
with industrial research centers.
Istituto Nazionale
di Oceanografia e di Geofisica Sperimentale - OGS
GEOPHYSICS OF THE LITHOSPHERE DEPARTMENT
Borgo Grotta Gigante 42/C
34010 Sgonico
Trieste, Italy
Tel: 0039-040 21401
Fax: 0039-040 327521
E-mail: gbrancolini@ogs.trieste.it
Web: http://www.ogs.trieste.it
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Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Measurements while drilling (data acquisition) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Geophysical data acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Seismic data processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Measurements while drilling (R & D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Wave modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
• Seismic modeling for exploration geophysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
• Ground penetrating radar for environmental problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
• Simulation of the ground motion caused by earthquakes and site response analysis . . . . 28
Seismic inversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
• The Cat-3D tomographic software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
• Joint 3D inversion of P, S and converted waves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
• Time-lapse 3D tomography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
• Seismic tomography for environmental studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Geophysical interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
• Joint Italian/Australian Marine Geoscience Expedition to the George V
Land Region of East Antarctica (Wilkes Land Glacial History, WEGA project) . . . . . . . . . . . . 39
• Physical properties and seismic stratigraphy of ODP Leg 178 well sites,
Antarctic Peninsula Pacific margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
• Orbitally-Controlled rhythmic sedimentation in the Wild Drift,
Antarctica (ODP Leg 188, Site 1165) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
• Subsidence at the Cape Roberts drill sites (Ross Sea, Antarctica)
from backstripping techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
• Cenozoic Evolution of the South Orkney Microcontinent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
• Structure and Cenozoic evolution of the South America - Scotia plate
boundary in the Tierra del Fuego region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
• Mapping the BSR on the South Shetland Margin (Antarctica)
and assessing gas hydrate and free gas quantities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
• Gas hydrate physical properties imaging by multi-attribute analysis - Blake
Ridge BSR Case History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
• Physical properties of sediment cores from the Antarctic continental margins . . . . . . . . . . 51
• Backstripping modelling in the frame of the Stratigraphical Development
of the Glaciated European Margin (STRATAGEM) - EU project . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
• Earth gravity field: measurements, data processing and interpretation . . . . . . . . . . . . . . . . . 53
• Synthetic Aperture Radar (SAR) remote sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Presentations at meetings and conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Book reviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Educational video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Visitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
International seminars in solid earth geophysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5

Introduction
The Department Geophysics of the Lithosphere (GdL) carries out studies and
researches in a wide range of applied and theoretical geophysics. It is organised
into four research groups, three operative groups and one support group. It
employees 20 researchers, 16 senior technician and 27 technician. During 2000
the Department gave hospitality to 7 grants.
Main activity of the GdL is the application of geophysical methods to the
knowledge of the underground. This knowledge has always been important in
human history, for finding out minerals and fresh water, but only in the last 50
years the need for accurate reconstructions of the underground geology drastically
increased, due to the world wide utilisation of the hydrocarbon as a primary energy
source.
Only in the last years however, grew the consciousness that the underground is a
masterpiece in the global environment and that its knowledge is of importance not
only for the exploitation of natural resources, but also for a sustainable
management of the global environment.
GdL activities during the 2000 were based on a deep consciousness of the central
role that the correct and sustainable managment of the underground resources
plays on the human development and impaction on the natural systems. The main
fields of our researches can be grouped in four main fields:
1) to recognise the presence of natural resources, with particular attention to
hydrocarbon,
2) to reconstruct the dynamic of the natural systems through the study of the
sediments,
3) to evaluate the impact of human activities to the underground system,
4) to produce high tecnology services for oil industry.
In all these fields, GdL takes advantage of its long experience in multichannel
seismic data acquisition and processing for oil industry.
In the hydrocarbon detection, a major improvement was reached by the first truly
3D Seisbit survey during the drilling of the Vallazza well. The Seisbit techniques is
a trade mark OGS-Agip and it allows the reconstruction of a direct and reverse
Vertical Seismic Profile during the drilling by listening to the noise produced by
the drilling bit. The 3D multi-offset in the Vallazza well produced, in a-quasi-real
time, an accurate and clear reconstruction of the geological strata below the
drilling bit.
The 2000 budget for natural resources’ study was 795,000 EURO, which derives
from research contracts with Agip and European Community
The study of the natural systems through the sediments was focussed in the high
latitude environments (Artic and Antartic). High resolution seismic, correlated to
sediment cores and drilling data, were used for detailed reconstruction of the last
glacial-interglacial cycles and to infer type and characteristics and dynamics of the
ice caps. Study have been carried out on two marine cruises, one in the Weddel
1

Sea, close to the Antarctic Peninsula, in co-operation with the US Antarctic
Program, the other off the Wilkes Land, in co-operation with the Australian
Antarctic Program.
The 200 budget for these studies was 450,000 EURO, mainly supported by the
Italian Antarctic Program.
The main problem we are facing in the application of the traditional onshore
seismic to environmental and hydrogeological studies, is the need to drastically
increase the resolution of the method: our approach follows three convergent
directions: i) by a theoretical approach based on the study and modelling of the
propagation of P and S waves in heterogenous-visco-elastic media; ii) studying the
source, by the acquisition of an high frequencies (up to 400 Hz) vibroseis system;
iii) the processing, by the application of evolved statics computation techniques.
The 2000 budget for these researches was about 500,000 EURO, mainly supported
by the Ministry for University and Research and by Fondo Trieste.
During the 2000, the GdL was also involved in significant activities for the oil
industry, particularly Agip. These were based on the Seisbit tecnology that was
applied for monitoring the bit position and carring direct and reverse WSP while
drilling.
The total budget for these activities was 1,230,000 EURO.
Giuliano BRANCOLINI
Department Director
2

PRESIDENCY
IGINIO MARSON
ADMINISTRATION
AND
SERVICESI
DEPARTMENT
OF
GEOPHYSICS
DEPARTMENT
OF
OCEANOGRAPHY
DEPARTMENT
OF
SEISMOLOGY
GIULIANO BRANCOLINI
RENZO MOSETTI
ALBERTO MICHELINI
ADMINISTRATION
OFFICE
DARIO COLONNELLO
WAVE
MODELLING
GÉZA SERIANI
GEOPHYSICAL
DATA ACQUISITION
DANIEL NIETO YABAR
SEISMIC
INVERSION
ALDO VESNAVER
MEASUREMENTS
WHILE DRILLING
(DATA ACQUISITION)
GIULIANO DORDOLO
MEASUREMENTS
WHILE DRILLING
(R & D)
FLAVIO POLETTO
SIGNAL
PROCESSING
NIGEL WARDELL
GEOPHYSICAL
INTERPRETATION
ANGELO CAMERLENGHI
3

Measurements while drilling (data acquisition)
Coordinator: Giuliano DORDOLO
G. CAPELLI
B. CATTANI
P. COMELLI
G. CRISTOFANO
P. GHIDINI
M. GIORGI
B. MOIMAS
V. PASCIULLO
A. SCHLEIFER
G. VASCOTTO
F. ZGAUC
In the year 2000 the ASTI group, keeping on the industrial application of the
Seisbit ® System 1, begins the field tests and research applications of the new
version of Seisbit ® System 2.
Starting the application of the new system means a complete revision and a
hardware and software redesign of the older version. It was necessary indeed to
increase the operational capabilities like interfacing with other systems. Most of
the hardware problems due to the synchronization between different systems has
been solved developing new hardware specifically for our purpose. Using these new
products with completely new software solutions, the new system is able to
manage the timing problems merging acquisition data form different systems with
different sample rates and different sampling characteristics.
Redesigning the system makes also possible to manage a huge amount of different
types of acquisition units such as Sercel SN348, SN368 and SN368E mixed almost
without limits.
The analogic section of the system has been modified and improved too, so in the
data transmission, as well as in the safety and in the assembling features.
Seisbit ® System 2 scheme.
5

Field operations showed a normal course, so it has been possible to get all the
targets:
Cerro F.- service well: seismic while drilling acquisition with ENI-AGIP. 55 channel
seismic survey. Main target top of cretaceous platform, deviation geometry control,
refraction survey for static corrections, indications on well casing operations.
Monte A.- service well: seismic while drilling acquisition with ENI AGIP. 60
channel seismic survey. Main target top of carbonate platform, deviation geometry
control, refraction survey for static corrections, indications on well casing
operations, receivers pattern test.
Cerro F.- research well: seismic while drilling acquisition with ENI-AGIP in the
frame of a research project. Down-hole instrumentation testing.
Geothermic service well: seismic while drilling acquisition service in Larderello
area for ENEL. Well geometry tracing. 164 channel pseudo-3D seismic survey.
Geothermic well
recording plan.
Rig: 12 pilot channels
L1 :22 channels, L2: 26 channels, L3: 26 channels
L4: 26 channels, L5: 26 channels, L6: 26 channels
First channel offset from centre of well: 325 m,
distance between two station units: 75 m.
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Vallazza research well: 3D-RVSP seismic survey. – CEE Research Project. This
Project required a large amount of technical and human resource, to realize an
experimental survey, with a 500 station units spread configuration. The main goal
was the validation of the 3D Seismic While Drilling. The spread configuration is
surely unusual: it consists in 2 circles centred on the well and 2 branches crossed
on the well too. The units pattern follow a saw-teeth shape, each segment
orthogonal to the radius of the circles, of 1000 and 2000 m length respectively. The
operation scheduling, people, instrumentation, acquisitions and data management
followed the expected flow without problems. There was some difficulty solving the
data management problems, due to the huge amount of them: over 130 Gbyte.
3D-RVSP recording
pattern.
7

After these research and testing phases, the new acquisition and pre-processing
techniques are validated and have been applied in the service and industrial
surveys.
Cerro Fal. Service well: 54 channels seismic survey, main target top oil trap,
refraction survey for static corrections, using stationary noise too, indications on
well casing operations.
Before data acquisition, it has to perform some preparatory activities, such as
scouting, topography units location, positioning of the recording materials,
mounting of the sensor pilots on the rig and the short refraction survey to have
the static corrections.
Elaboration and application of an accurate static correction is a very important
step in the processing of VSP and VSP CDP mapping. Data correctly elaborated are
useful in drilling too, i.e. to schedule the casing operations.
Example of a while drilling seismic
survey area.
8

Therefore, having beside a high elevation spread and a datum plane quite deeper,
a lot of effort has gone into studying and designing the survey, first of all using the
already existing informations (seismic lines, up-hole survey, stacking chart,
dromochrones and thematic maps) and then the foreseen stratigraphy. After the
ray-tracing, this set of elements allowed to plan the data recording geometries,
fitting the basis extension with high channel number (48), using the Summit
telemetric system and a Hydrapulse as source.
Moreover, together with this new approach using short refraction for a while
drilling survey, data are dynamically correct with Seisbit ® information until the
datum plane depth.
The ASTI group worked in collaboration with more crews up to 24 people, most of
them OGS senior technicians and engineers and some people from the contractors
companies.
After the testing phases of the Seisbit ® 2, innovation studying and designing are
pursued, to improve the automation capabilities and the data storage and
elaboration features in field.
SHORT REFRACTION SURVEY RECORDING PLAN
Spread configuration
SEISBIT
channel
SEISBIT
channel
SEISBIT
channel
SEISBIT
channel
SEISBIT
channel
SEISBIT
channel
P.s.: shot point
G1 - G48: geophones of the seismic short refraction profile
Short refraction spread example.
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Geophysical data acquisition
Coordinator: Daniel NIETO YABAR
S. BARBAGALLO
L. BARADELLO
R. BOLIS
A. BRATUS
G. COVA
C. D’AMICANTONIO
E. DEL NEGRO
F. FANZUTTI
M. GROSSI
B. MARINO
P. PAGANINI
M. POROPAT
G. VISNOVIC
The wide and profitable group activities, supporting the other research groups, are
listed below. Acquiring appliances have been implemented in all the operating
fields, such as GPR, geoelectric, onshore and offshore seismic investigations.
A methodological research project has been presented and approved at the Fondo
Trieste, with the results of a further technological development of the acquisition
systems and an improvement of scientific technicians.
Acquiring appliances are:
SEISMIC ON-SHORE:
Positioning
• Total Station SOKKIA
• DGPS
• Infrared level LEIKA 3003
Energization
• MiniBang ISOTTA
• Seismic Sources Power Weight Drop PWD-80
• IDROBANG for well energization
• Vibroseis-MINIVIB (to be completed)
• Hammer
Geophones
• Single 100 Hz
• Array of 6x20 Hz
• Array of 12x10 Hz
Recording
• SUMMIT telemetric 140 channels
• OYO DAS-1 96 channels
SEISMIC OFFSHORE:
Positioning
• DGPS
• Communication Technology Navigation System
Energization
• PULSAR 2000 Power Unit for Uniboom
• IDROBANG for water energization
• GI-Guns
• Water-Gun
• Sure Shot gun Controller
• Bauer I 28.0 – 75, high-pressure air compressor
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• Standard 20’ container modified to host the compressor, the high-pressure air
control and the airgun workshop, complete with all the required electric
wiring.
Streamer
• 1200 m ITI solid state
• Monochannel 3.5 m Geometrics
• Single hydrophones and array hydrophones (10 single in array)
• Streamer Tester A-2000
• Digicourse streamer position control system
• ARDEA streamer winch
Recording
• OYO DAS-1 recording system, expanded to 96 channels, with three IMB
3480/3490 recording modules.
• DELPH II System (version n° 2 seismic channels)
DATASONICS - CHIRP-II (sub-bottom profiler)
ERT (Earth Resistivity Tomography)
• Resistivimeter Syscal-R2, IRIS Instruments
• Output : 800V- 2,5A
• Ground energization power supply: external
- 250W using 12V input
- 1200W using 220V input
• Multinode System of IRIS, to control from 32 to 256 intelligent nodes
GPR (Ground Penetrating Radar)
• SIR-2000 GSSI
• Antennas:
• SUBECHO 35 MHz
- SUBECHO 70 MHz
- GSSI 100 MHz bistatic
- GSSI 200 MHz
MAGNETOMETRIC ACQUISITION:
• Cesium Gradiometer G-858, Geometrics
• Proton Magnetometer G-856, Geometrics
The group’s activities are:
• Project Tasman Sea. Geophysics research project in the Tasman Sea, with the
R/V research ship Polar Duke, in cooperation with BGR of Hannover.
Multichannel seismic lines and magnetometry were displayed.
• High resolution seismic in Mica. The high-resolution 3D seismic program of
the Mica Project has been acquired using the new Summit telemetric
acquisition system and comprehends the sites of S. Pier d’Isonzo and Iamiano
11

(GO). The energizing systems were an Isotta gun and PWD. In the Mica project
127 transepts of 20-channels have been acquired, for a total amount of 994
points, while in Iamiano the acquirement grid was provided by 600 channels
and 530 energization points.
• Integrated metodology in the Mica project. Combined to the high resolution
seismic, the two sites of S. Pier d’Isonzo and Iamiano were characterised using
GPR, ERT (earth resistivity tomography) and magnetometry. The 2D
resistivity profiles had length from 31 to 315 m.
• TRUCK Project. In February 2000, for the AGIRE srl society a magnetic survey
was carried out on an area near PERPIGNAN (F). The aim of the survey was
the determination of magnetic anomalies connected with the supposed
presence of a buried vehicle. The area was delimited with a total station
SOKIA. The vertexes of the area were joined with the local topography. The
high-resolution magnetic acquisition was carried out with a portable cesium
gradiometer GEOMETRICS mod. G-858 along parallel profiles with a 2-m
range. Magnetic data were reduced by the field reference model IGRF 2000.
• KRSKO High Resolution. In February 2000 three high-resolution seismic
profiles, with a total length of 4 km were recorded in the surroundings of the
KRSKO nuclear-power plant (SLO). This acquisition was performed in the
framework of the EU-programme PHARE to complete data acquired in 1999.
• Project LARSEN. The NSF project “Paleohistory of the Larsen Ice Shelf:
Evidence from the Marine Record”, with the aim of reconstructing the
history and collecting sedimentological, biostratigraphical, biological and
oceanographical information on the environmental change of the sea floor in
the area that, until five years ago was still covered by the Larsen ice platform
(Eastern part of the Anctartic peninsula). Among the various applied surveys
the group took part in data acquisition with multibeam echosounder, Side
Scan Sonar and monochannel reflection seismic. The expedition has been
carried out in May 2000, on the icebreaker N.B. Palmer (USA).
• Extended Program Geophysical Research in the surroundings of the Krsko
NPP. Three new seismic lines were made with a double purpose: to clarify the
position of some faults zones and correlate the seismic data with logs of the
drill hole Drnovo 1.
• Project STRATAGEM. Research project with the R/V research ship Dana, in
three different investigation areas. In one of these, the Faeroe-Shetland
margin, the main aim was the construction of a mid –to late Cenozoic
stratigraphic framework for the Faeroe-Shetland and the setting up an
evolution model for the Faeroe-Shetland margin, with particular emphasis on
the development of shelf-margin progradational wedges. During the fieldwork
4 monochannel high-resolution reflection profiles have been recorded, for a
total amount of 300 km. The acquisition system was composed by a GI-Gun
(90 in 3 ) checked by a Real Time System Sure Shot, one streamer with an array
of 10 Hydrophones 1.6 m space and one recording system Elics Delph-2x. The
positioning was supplied by SHIPMATE GPS equipped with differential GPS
corrector.
12

• Offshore gravimetric survey “CERVETERI”. The gravimetric offshore program
in the area covered by the IGM 1:50000 “CERVETERI” sheet was executed for
the “Servizio Geologico Nazionale” with a floor gravimeter Lacoste &
Romberg on the ship N/R VEGA owned by Sopromar. 300 points, with a 1-km
interval between them, have been measured.
• Integrated methodologies at the Doria Cave. This test was carried on to define
the applicability of the ERT, GPR and magnetometry in detecting underground
caves in Karst area.
• High-resolution mono-channel seismic Acque Profonde. The investigated area
comprehended sea/littoral, lagoon and continental/fluvial multiple
environments in the Marano Lagoon. The survey was carried out by the
employment of two high-resolution acquisition systems linked to a satellite
positioning system. The first was composed by a Delph monochannel
acquiring system synchronized with a Uniboom high frequency
electrodynamical impulse source. The second by an integrated acquiringenergizing
Chirp-datasonic system using a non-impulsive high frequency
source, allowing centimetric resolutions.
• High Resolution Survey in the Barcis Lake. Research project for the “Regione
Friuli Venezia Giulia” with monochannel seismic. A Uniboom energizing
source, a Delph acquiring system and a DGPS positioning system were
mounted on a boat provided by the Barcis municipality.
During this year Salvatore Barbagallo and Giorgio Cova have retired: we would
like to thank them for their work.
High resolution
seismic in Mica. 3D
data acquisition in
the Iamiano site.
13

High-resolution mono-channel
seismic Acque Profonde.
The off-shore workstation.
Integrated methodologies at the Doria Cave.
The ERT (Earth Resistivity Tomography) image.
14

The GPR instruments.
Integrated methodologies in the Mica project.
Geoelectrical data acquisition.
Extended Program
Geophysical Research
in the surroundings of
the Krsko NPP.
Acquisition near the
nuclear power plant.
15

Extended Program
Geophysical Research
in the surroundings
of the Krsko NPP.
Seismic line.
Integrated
methodologies at the
Doria Cave. GPR
(Ground Penetrating
Radar) section.
TRUCK project. High resolution
gradiometric acquisition.
Mono-channel
seismic offshore.
Data acquisition.
16

Seismic data processing
Coordinator: Nigel WARDELL
G. CENTONZE
L. CERNOBORI
P. DIVIACCO
M. MARCHI
R. OLIVOTTI
C. PELOS
M. ROMANELLI
R. SINCERI
L. SORMANI
F. ZGUR
During the year 2000, the Processing group was involved in a variety of projects,
from deep crustal studies to very high resolution land and marine surveys in both
2-D and 3-D. However, the year was marred by the tragic loss of Licio Cernobori
who died suddenly after a short and terrible illness. His experience, self-motivation
and enthusiasm had made him a key member of the group. He will be greatly
missed, as a colleague and also as a friend.
One of the projects in which Licio was very much involved, was “Geophysical
research in the surroundings of the Krsko Nuclear Power plant”, to study the
geological stability of the area around the nuclear power plant at Krsko in
Slovenia. The three high resolution lines that had had to be postponed, in 1999,
due to inclement weather conditions, were acquired in the spring. Although field
tests had been conducted on the first line, during the winter, further testing was
performed to take into consideration the different weather conditions for the three
remaining lines. The group utilised the Vista processing package installed on a
laptop computer to analyse these field tests. The data were subsequently finalised
in the processing centre in Trieste. An elaborate processing sequence was used to
attempt to overcome problems introduced by ploughed fields and shallow peat
layers. These near surface conditions caused static problems and absorption of the
high frequency component of the frequency spectrum.
To complete the interpretation of the area and to better define the geological
structures, three additional lines were planned in the vicinity of the power plant.
These lines were semi-regional in character; the acquisition parameters were midway
between those of the regional and the high resolution lines. Since the Isotta
rifle, which was used for the high resolution, was not considered to have the
penetration necessary for the target structures, a new source Hydrapulse, a
powered weight drop, was used for these lines. This choice entailed more testing
in the field to optimise the recording parameters for the new source and objectives.
The processing group provided the technical expertise during these tests. This was
followed by quality control (QC) and processing in the field to produce preliminary
stacks. Since these surveys were very close to the nuclear power plant, 50 Hz noise
from the power cables emanating from the power station, was very evident on the
field records. The QC and processing in the field was important to monitor that the
level of this noise was not saturating the signal and that it could be attenuated in
the processing phase.
The final processing of these data, which was performed at the processing centre
in Trieste, was tailored to detail the particular objectives and to match the regional
lines recorded the previous year. To assist the interpretation, the final stack
sections of both datasets were migrated and converted to depth. All the processing
17

sections were included, in digital form on a CD-ROM, with the interpreted results
and conclusions in the final report.
Another important project in which the group was involved was the CROP or Deep
Crustal project. During the year, the processing of first part the seismic line CROP-
11 (From Lazio to Abruzzo) was finalised. A non-standard processing sequence
involving noise reduction, coherency enhancement, array simulation and
refraction statics had been derived to improve continuity and enhance the signal
to noise ratio, especially at deeper depths. This sequence is also being applied to
the second part of this line (from Abruzzo to the Adriatic Coast) which the
processing group had been involved in the field QC and processing in 1999.
The group was also involved in QC and field processing in the marine environment
in the WEGA project, offshore Wilkes Land in Antarctica. As part of this project to
study the glacial history, analysts from the processing group participated in this
cruise. In the spring of 2000, 1500 kms of multi-channel seismic were acquired by
an Australian research vessel. Following initial processing on board, the data were
transported back to Trieste for further processing and finalisation. The final data
were presented at an International Conference in Tasmania in December.
The research activities of the group continued with the EU project Very high
resolution marine 3D seismic method for detailed site investigation (VHR3D)
which is aimed at a cost-effective detailed 3-D reconnaissance of the seabed
sediment properties for geological, geotechnical and environmental site
investigation purposes. The group plays a major role in this three-year project
coordinating OGS’s contributions in processing, tomography, geotechnical
studies, and seismic modelling. In this third year of the project, limitations in the
acquisition technology, restricting the available navigation information and the
range of offsets, reduced the involvement of the other OGS contributors. However,
additional research had to be undertaken by the processing group to include preprocessing
corrections in 3-D for wave-motion and tidal effects.
Initial work had already been completed by the group, defining a methodology in
2-D that used static corrections to correct for wave motion. This had been
extended in the second year to include geometry regularisation to take into
account variations in cable positions, and hence offset, which were not able to be
recorded by the navigation system. This methodology was presented at the EAGE
meeting in Glasgow in June 2000. The 3-D corrections were based on a similar
statistical analysis of the first break arrivals after common offset spatial averaging
that had been used in 2-D. In the 3-D case, the spatial averaging had to be
performed in an areal sense to include not only the component of the wave motion
but also the component due to tidal differences between lines. First results on a
dataset recorded in the Dover strait were encouraging.
Members of the group participated in the next VHR3D cruise in St. Austell Bay in
Cornwall where the two different multi-cable acquisition systems, proposed in the
project, were used. After seeing these acquisition systems in operation a number
of modifications were made to improve the technique. Since the cables were seen
to act independently at times, a separate component was derived for each cable
rather than for each shot. Also, different 3-D spatial filters had to be introduced to
18

allow for the different spatial sampling in the in-line and cross-line directions.
Results from the St. Austell Bay survey showed that the methodology worked well.
3-D stack cubes using a one metre bin size were produced on datasets from both
the acquisition systems. The complex channeling in the area was well delineated
with a vertical resolution of less than half a metre. A presentation on this 3D
methodology has been accepted for the 63rd Annual Meeting of the EAGE in
Amsterdam in June 2001.
The group was also involved in a research project, funded by ENI (Agip Division)
through the University of Parma to study crustal movements and the processes of
convergence and sedimentation in the Eastern Mediterranean. Within the project,
1000 kms of seismic data, recorded by OGS in the seventies, was reprocessed and
interpreted in order to design scaled physical models for sediment deformation
experiments in the laboratory. This physical modelling was performed by a team
from the University of Parma (Department of Earth Sciences) and IGN-CNR
Bologna. The reprocessed data crossed the eastern Mediterranean ridge
accretionary complex and extended to the Herodotus foredeep and African foreland
(Nile river deep sea fan). The reprocessing involved re-generation of stack sections
from the original tapes, migration and depth conversion. Pre-stack depth
migration was also performed on selected parts of the profiles with Geodepth ©
software. The migration velocity focusing analysis and grid tomography in
Geodepth © was also used to study the velocity distribution and define possible
facies changes in the salt sequence.
The development of the group’s capabilities in 3-D processing continued with the
MICA project. The aim of this project, funded by the ‘Fondo di Trieste’, was to
define the flow of underground water in the zone of the Carso. Two high resolution
land 3-D surveys were planned in the project; one was acquired in the early part of
the year, whilst the second towards the end of the year. The processing group was
involved both in the preparatory phase and in the processing of the recorded data.
Notwithstanding the problem of lack of high frequencies in data recorded on land,
the 3-D stack cube of the first survey produced good results in the area of interest
after the application of residual static correction routines.
The group has continued its collaboration with OCSA (Orellana Consultores S.A.
Madrid), processing a number of high resolution land lines to plan the best routing
for rail and road tunnels under mountainous regions. These data tend to be
inherently noisy and lacking in continuous reflections due to the deformed, often
metamorphic, areas in which they are recorded. Careful noise reduction and
continuity enhancement routines have been used in the final sections. Continued
close ties with other academic institutions produced a number of small processing
projects. Two 3-D surveys were processed with the University of Trieste (DINMA),
one line in the Acqua Profonda project for the local Friuli Venezia Giulia region
(also with DINMA), and a line acquired in Sardegna by the University of Cagliari.
The recovery and archiving of old multi-channel seismic data has continued to be
an important part of the group’s activities. All the Mediterranean data recorded by
OGS in the seventies, and about 70% of the data recorded by OGS in the Antarctic
in recent years, have been transcribed from their original field format to SEG-Y on
19

3480/90 cartridges. The group also performed a transcription service for
ENEL/ERGA, copying their entire seismic field data library onto cartridges and
CD-ROM.
Processed stack data from the Antarctic is also being transcribed onto CD-ROM as
part of the Seismic Data Library System (SDLS) project. The Antarctic Seismic
Data Library System (SDLS) provides open access to multi-channel seismic
reflection data collected by all countries in the Antarctica, to facilitate large-scale
cooperative research projects. The SDLS has 11 library branches that are located
in 10 countries world-wide. Researchers may go to any library branch to inspect
Antarctic multi-channel seismic reflection data. The processing group performs
any necessary reformatting, filtering and scaling to the stack data before
transcribing them, in SEG-Y format, onto CD-ROM together with a visualisation
program.
VHR3D - Common offset surfaces (Dover)
Results of the 3D
methodology for
determining static
corrections for tide and
wave motion effects.
A common offset
surface of the water
bottom is shown
without
corrections (top),
with tidal corrections
(middle) and with tidal
and shot corrections
(bottom).
20

Results of application
of the static
corrections to a
stacked 3D data
cube. The original
data is on the left
and the static
corrected cube on
the right.
VHR3D - Dover 3D cube
St. Austell Bay 3D Cube
Time slice at 33 ms.
Time slices from the
processed
3D cube from
St. Austell Bay
after application of the
static corrections for
tide and wave motion.
The high resolution
definition of the
channels is clearly
evident.
WAVE MODELING
St. Austell Bay 3D Cube
Time slice at 35 ms.
21

S
MS-53 SP 1175-1475 Velocity Analysis “semblance”
N
An example of the migration velocity focusing analysis
using the GeoDepth Pre-stack depth imaging package.
A line extracted
from the Mica
project 3D cube
showing the
improvement
obtained by the
application of 3D
residual statics
(bottom) over the
original stack
data (top).
22

Measurements while drilling (R & D)
Coordinator: Flavio POLETTO
C. BELLEZZA
P. CORUBOLO
A. CRAGLIETTO
M. LOVO
M. MALUSA
L. PETRONIO
G. PINNA
U. TINIVELLA
S. TINONIN
The research was primarily aimed at studying in deep and extending the applicability
of the seismic while drilling technology as well as increasing the industrial
potential by raising the number of geological information given by the method.
The projects developed by the SERE group in collaboration with ENI/AGIP are the
following:
A) Acquisition of a 3D reverse VSP using the drill-bit source during the drilling of
an ENI/AGIP well in Sicily (Italy).
Such a method, which is the only capable of acquiring an onshore 3D VSP on
a large number of acquisition levels, was applied in cooperation with the “while
drilling” data acquisition group (ASTI).
The experiment, funded with the contribution of the 3D-RVSP European Union
programme (Contract Thermie OG 278/98 IT/UK, partners OGS, ENI/AGIP and
Prosol Technology), allowed us to acquire a good quality 3D Seisbit dataset.
The receivers were placed on a 15 square Km area and the investigation was
carried out on a 3 km long well section.
We used radial and circular seismic lines in a geometry suited to discriminate
the signal and noise arrivals (first Figure). During the survey setup we
computed some 3D elastic models and after the acquisition phase data have
been processed as multioffset vsp sections along the cross shaped radial seismic
lines. We are still processing the circular lines with the aim of obtainig a 3D
reverse vsp imaging.
B) Theoretical analysis and experimental study of signals measured in the drill
pipes and of reflection coefficients at the drill-bit / rock interface. This allowed
us to measure the acoustic impedance of the drilled formations and to gather
information about the signal amplitude in relation to changes in the drillstring
and drilled rock (formation evaluation while drilling).
C) Feasibility study for the Geosteering project (ENI/AGIP). This project is aimed
at steering the drilling operations basing on “while drilling” information.
Particularly, the research is aimed at the tuning of a method and an acoustic
system to be used downhole for monitoring the lithology in the vicinity of the
drill bit for the purposes of drillers and geopysicysts.
The feasibility study includes the use of downhole instruments and the
syncronization with surface measurements. Field and laboratory tests have
been carried out with the prototype instrument called Instrumented Sub
ENI/AGIP. Such measurements allowed us to detect the drill bit signal also in
highly unfavorable conditions, even for the surface measurements (second
Figure). Numerical modelling methods were developed to analyze the signals
propagation throughout the drill string. Moreover, the research was extended
23

to study methods suited to predict overpressure zones using SWD and to the
analysis of electromagnetic signals in a well.
D) Feasibility study and preparation of the technology for the extension of the
method to the deep sea and downhole environments, in collaboration with
ENI/AGIP and Tecnomare.
E) In deep study and analysis of datasets collected during a SWD experiment
carried out in a tunnel. Study of the applicative contexts, of the tunnel boring
machine signal resolution and of the signal and noise components.
F) Study and multioffset processing of a dataset acquired in a geothermal area
along seismic lines laid out in a multiradial geometry with respect to the well
head (in collaboration with ENEL). Analysis and preparation of a dataset for
tomographic inversion, in collaboration with REDS.
24

Wave modeling
Coordinator: Géza SERIANI
Seismic modeling for exploration geophysics
J.M. CARCIONE
F. CAVALLINI
G. SERIANI
The numerical modeling of seismic waves plays a key role in exploration
geophysics, reservoir engineering, and environmental studies. In the year 2000,
OGS has continued this kind of activity under the aegis of the European
Community (research program “Detection of Overpressure Zones from Seismic
and Well Data - ODS”), with emphasis on the following topics.
The first one is the estimation of gas-hydrate concentration and free-gas
saturation. When no direct measurements are available, a detailed knowledge of
the compressional and shear velocity is essential for the quantitative estimation of
gas hydrate and free gas in bottom-simulating reflectors (BSR). Discrepancies
between experimental velocity profiles and the velocity for water-filled sediments
reveal the presence of gas hydrate (positive anomaly) or free gas (negative
anomaly). A three-phase Biot-type theory yields wave velocities of sediments
saturated with water and gas hydrate, while the Hill average is used to model the
patchy free-gas saturation below the BSR. The model has been applied to field data
acquired by the r/v OGS Explora in Antarctica.
Velocity field across a section parallel
to the South-Shetland Margin in Antarctica.
The BSR is evident at the left where
a low-velocity layer, caused by the presence
of free gas, is embedded in a higher
velocity background.
A line extracted
from the Mica
project 3D cube
showing the
improvement
obtained by the
application of 3D
residual statics
(bottom) over the
original stack
data (top).
Concentration map of gas hydrate
(positive values) and free gas (negative values)
corresponding to the BSR offshore the
South-Shetland Islands. The figure shows
the hydrate concentration (and free gas
saturation) multiplied by the porosity
(i.e., the volume concentration). In this way,
we can compare the content of hydrate and
free gas between zones of different porosity.
25

Poisson’s ratio as an indicator of overpressure has been investigated. Poisson’s
ratio values of dry samples are significantly smaller than those of fluid-saturated
samples. The values are anomalously high for high pore pressure, with the
possibility of differentiating between gas-saturated, brine-saturated and oilsaturated
porous rocks. Two overpressure models, based on oil/gas conversion and
disequilibrium compaction, have been developed to obtain Poisson’s ratio versus
differential pressure. Poisson’s ratio is approximately constant at high differential
pressures and increases (decreases) for saturated (dry) rocks at low differential
pressures. Fluid type can be determined at all differential pressures from Poisson’s
ratio. Moreover, the analysis is extended to the transversely isotropic case by
computing the three Poisson’s ratios. Experiments performed on cores, under
different pressure conditions, and calibration of the models with these data,
provide a tool for inverting pore pressure from seismic data.
1
0.2
0.15
0.1
gas
water
oil
(a)
2
0.3
0.25
0.2
0.15
0.1
gas
water
oil
(b)
3
0.25
0.2
0.15
0.1
gas
water
oil
(c)
0.05
0 20 40 60 80 100
Effective pressure (MPa)
0.05
0 20 40 60 80 100
Effective pressure (MPa)
0.05
0 20 40 60 80 100
Effective pressure (MPa)
Anisotropic Poisson’s ratioes σ 1
(a), σ 2
(b) and σ 3
(c), for brine-, oil- and gas-saturated Berea
sandstone versus effective pressure, compared with experimental dry-rock Poisson’s ratios.
The dashed line is the best-fit curve to the dry-rock data.
well 1B
NW
SE
formations
vel. P (km/s)
Snapshot of the
seismic wave field
propagating in a
complex geological
structure during a 3D
simulation of a
seismic-while drilling
experiment.
depth (km)
distance (km)
26

Phase velocities
of the five wave
modes
propagating in
partially frozen
Berea sandstone
versus water
proportion.
Phase velocity (km/s)
5
4
3
2
1
0
P1
S1
P2
S2
P3
(a)
0.05 0.1 0.15 0.2
Water proportion
Snapshot of the rock-frame
vertical particle velocity
corresponding to the wave
modes illustrated
in the previous figure.
The compressional waves
are labeled P1, P2 and P3,
and the shear waves
are labeled S1 and S2.
Finally investigation on dynamics of frozen porous media has been conducted. The
knowledge of the physical properties of frozen soils is essential, in polar areas, for
the exploitation of mineral resources and for the construction of highways and
pipelines. A three-phase Biot-type theory has been developed to describe a seismic
wave propagating in a porous rock filled with ice and water. The model predicts
three compressional waves and two shear waves, and takes into account energy
dissipation and wave dispersion as observed in rocks. Attenuation is introduced
with exponential relaxation functions, which allow a differential fomulation based
on memory variables. The wavefield is computed with a grid method based on the
Fourier differential operator in space and a Runge-Kutta time-integration
algorithm. The presence of slow quasi static modes makes the differential
equations stiff and hence numerically untractable as such. But a splitting timeintegration
algorithm has allowed to solve the stiff part analytically. The algorithm
is second-order accurate with respect to time and has spectral accuracy in the
computation of the spatial derivatives.
27

Ground penetrating radar for environmental problems
J.M. CARCIONE
F. CAVALLINI
G. PADOAN
G. SERIANI
The ground-penetrating radar (GPR) has unique capabilities as a subsurface
exploration device; as such, its applications (since 1992) include archaeology,
mining, glaciology, hydrogeology, and environmental remediation. But its
performance is highly sensitive on the knowledge of the physics of the medium and
of the instrument itself. Therefore, basic research in this field is of crucial
importance for pracical applications as well. Many concepts and techniques that
were devised for seismic waves can be applied to the processing of GPR data, in
virtue of the mathematical analogy between electromagnetic and elastodynamic
equations. This research, funded by the Regional Government of Friuli - Venezia
Giulia (northeastern Italy), aims at exploiting these methods for the monitoring of
a polluted area.
The exploding-reflector method, originally developed for seismic waves, has been
adapted to produce zero-offset synthetic radargrams without need to compute
common-shot records. The basic underlying idea consists in assuming that each
reflecting point acts at the initial time as an instantaneous source of motion with
a magnitude proportional to the normal-incidence reflection coefficient. The
magnetic permeability is used as a free parameter to obtain a constant-impedance
model and, so, to avoid multiple reflections. Moreover, the condition that the phase
velocity remain unchanged also requires the scaling of the permittivity and of the
conductivity. Thus, the method generates normal-incidence reflections, i.e., those
having identical downgoing and upgoing wave paths. In an example with
transverse-magnetic equations, this method has shown more accuracy, but less
efficiency, than the plane-wave technique.
Analytical solution for lossy anisotropic media has been developed. Microstructural
features, fine layering, and fluid-filled cracks give rise to electric and magnetic
anisotropy, while mineralized water in the fractures makes conductivity
anisotropic. Water relaxation and ferromagnetism are responsible of energy
dissipation. This motivates an orthotropic constitutive law in which attenuation
stems from the Debye model. The corresponding solution is obtained in the
frequency domain from a change of coordinates that turns Maxwell’s equations
into Helmholtz equations, which are solved analytically. Then, the solution in time
domain is recovered by numerically computing the inverse Fourier transform. The
results are in agreement with a plane-wave analysis of the slowness, the
attenuation and the energy velocity.
Simulation of the ground motion caused by earthquakes
and site response analysis
E. PRIOLO
G. LAURENZANO
Synthetic seismograms computed as a solution of the full-wave propagation
through a realistic geological structure can reproduce accurately much of the
effects of medium heterogeneity and local soil conditions on the ground motion
caused by earthquakes. They are a powerful tool for building seismic hazard
scenarios as well as for performing site response analyses. For this kind of studies,
we currently use two methods, i.e. the 2-D Chebyshev spectral element method
28

(SPEM) and the Wavenumber Integration Method (WIM), which have very
different features.
The 2-D Chebyshev spectral element method (SPEM) is a high-order finite element
technique, which solves the variational formulation of the equation. It has been
entirely developed at OGS by E. Priolo and G. Seriani. The use of irregular meshes,
as well as the high computational accuracy, which derives from the use of highorder
Chebyshev polynomials, make the SPEM particularly suitable to solve
numerically the seismic wave propagation through complex geological structures.
The WIM solves the 3-D elastic full-wave equation in a plane layer medium. It has
been developed by R. Herrmann at St. Louis University. Synthetic seismograms
contain all wavefield phases, in both the near- and the far-fields. Furthermore,
simulations can be set up very simply, since the method needs only few parameters to
be defined. These properties make WIM suitable for performing predictions at a regional
scale, as well as for kinematic modelling of the rupture process along the fault.
The methodological development has been focused on improving the capability of
the SPEM for building complex models. In the standard implementation, the
spectral element method decomposes the whole model into a patch of sub-regions
having constant physical properties. This approach is inadequate to represent geomodels,
since they usually feature small scale heterogeneities and medium
properties that change continuously in the space. This fact motivated the
development of a different approach, in which 1) the geological structure is builtup
through an interpolator which handles discontinuities, and using a minimum
number of control points and lines, and 2) the mesh size adapts continuously to
the medium properties and is controlled by few geometric constraints.
In general, the activity has been developed mainly within a number of national
research projects funded or co-ordinated by the GNDT1 and GNV2. During year
2000, one three-years project – the Catania Project – finished its activity, while five
new research projects started. In particular, the latter include a one-year project –
the Marche Microzonation Project – and four three-years projects, namely:
1) Development and Comparison between Methodologies for the Evaluation of
Seismic Hazard in Seismogenic Areas: Application to the Central and Southern
Apennines; 2) Damage Scenarios in the Veneto-Friuli Area; 3) Detailed Scenarios
and Actions for Seismic Prevention of Damage in the Urban Area of Catania; and
4) Integrated Seismic Methods Applied to the Investigation of the Active Volcano
Structure. An Application to the Phlegrean Fields Caldera. We will shortly present
some of those projects in the following.
The Catania Project aimed at evaluating the seismic risk of a highly urbanised area
typical of the Mediterranean region. The OGS contribution of the last year was
twofold. In a first part, we simulated a recent event, the M 5.8 earthquake, which
struck Eastern Sicily on December 13, 1990, and was recorded by the Catania
ENEA-ENEL accelerometric station. Seismograms computed using the SPEM
agree very well with those recorded by the accelerometric station. On the contrary,
any plane layer representation, which simplifies the complex structure used by
SPEM, does not provide a comparable agreement. In this case, the synthetic
seismograms are computed by the WIM. This study has several outcomes. Firstly,
29

it demonstrates that the whole approach, based on the SPEM, previously used to
simulate the ground shaking for a destructive scenario earthquake, provides
reliable results. Secondly, it shows that the model used to represent the crustal
structure beneath this area is realistic. Indeed, simplified models may not be
adequate for predicting the site response. Moreover, the high amplitude displayed
by the Catania station during the 1990 earthquake can be explained as a combined
effect of site and structure-path.
The second contribution to the project was the analysis of the environmental
seismic noise data (microtremors) acquired within the Catania municipal area in
May 1999, with the aim of improving the prediction of the seismic ground motion
locally. To this end, we followed Nakamura’s approach which, as proven, provides
the main features of the dynamic ground response through the calculation of the
spectral ratio between the horizontal and the vertical components (i. e., H/V ratio)
of background microtremors. We found (first Figure) that several sites exhibit
irrelevant or weak amplification, i. e., sites which are located either on lava (for
example, the sites in the Catania centre or in the northern part of the municipal
area) or well-consolidated sedimentary
soils (Western districts of the city).
The only sites which bear evidence of
some amplification are located on
either fillings soils lying over lava, or
on the fine alluvial deposits of the
Catania Plain.
Catania Project. Map of the Catania
municipal area showing the pseudoamplification
estimated from background
microtremor horizontal to vertical spectral
ratio (HVSR).
The color and size of the circles indicate
peak frequency and amplitude of the
HVSR, respectively. Blue and white circles
indicate sites with very low pseudoamplification
(< 2) and flat response in
the low frequency range, respectively.
Contour lines indicate the depth of the
top of the light-blue clays formation,
which has been assumed as a possible
seismic bedrock. The background map
shows the simplified geotechnical
zonation.
30

The Marche Microzonation Project is a two-year research project, whose general
objective is the detailed microzonation of some selected cities of the Marche
Region. The OGS contribution develops within the second year of the project. The
aim is to perform a detailed simulation of the ground motion and site response
analysis for the cities of Treia (MC) and Cagli (PS). Numerical simulations are
performed using the SPEM. The reference event is a M=5.7 earthquake, and it is
associated to two normal faults located beneath the cities, respectively. The second
Figure shows a wavefield snapshot for the simulations performed for Treia.
Marche
Microzonation
Project. Wavefield
snapshot (P-SV
acceleration) of the
SPEM simulation
performed for the
town of Treia
(Macerata, Marche,
Italy). The locations
of the town and
source are
indicated at the top
and by the couple
of arrows,
respectively.
Within the project entitled Damage Scenarios in the Veneto-Friuli Area, the
activity of the first year aims at building-up a ground shaking scenario at a regional
scale for the area surrounding the town of Vittorio Veneto. The reference
earthquake is the M=5.8 event, which occurred in “Cansiglio” on October 14, 1936.
The associated fault mechanism is oblique, with a strong character of reverse fault.
Both point source models and rupture propagation along an extended fault are
considered. The dominant feature of the geological structure is the thrust
corresponding to the Alpago-Cansiglio highlands, the southern edge of which
features a very steep change of elevation. The reference earthquake is associated to
this thrust. The particular location of the source, which is rather deep and right in
the middle of a structural discontinuity, makes it possible to tackle this study with
a non classical approach, that is differentiating the surface structure and top
elevation in different zones, i.e., the plane area, the foot-hill zone, the alpine
valleys, and the mountain area, respectively. The areas of maximum ground
shaking predicted in this way agree very well with those observed in the
macroseismic field (third Figure) even just by using a point source.
31

Collaborations: National Group for the Defence Against Earthquakes (GNDT) and
National Group of Volcanology (GNV), belonging formerly to the National Council
of Research (CNR) and currently to the National Institute of Geophysics and
Volcanology (INGeV); Politecnico di Milano; Università della Basilicata (Potenza);
Università di Catania; Università di Camerino; Università La Sapienza (Roma);
Università di Napoli; Università di Udine; Università di Trieste; National Institute of
Geophysics and Volcanology.
A
B
Damage Scenarios in the Veneto-Friuli Area.
The October 14, 1936 (M=5.8) “Cansiglio” earthquake.
(A) Observed macroseismic field, and (B) peak ground
accelerations predicted numerically by the WIM.
32

Seismic inversion
Coordinator: Aldo VESNAVER
The Cat3D tomographic software
G. BÖHM
M. PERONIO
The software package Cat3D allows the 3D traveltime inversion by adaptive
irregular grids, for arbitrary recording geometry and combinations of different
wave types: direct, reflected, refracted and diffracted arrivals. Since it allows, for
example, the joint inversion of surface and VSP data, it is a valuable tool for
calibrating the seismic surveys with the well information.
During the year 2000, the software commercialization was supported by the OGS
partners: Paneura (Trieste, Italy) and Fact (Houston, USA). Paneura had a booth at
the EAGE International Conference and Exhibition in Glasgow. Various copies of
Cat3D were installed in Europe.
A major improvement of the software efficiency was an aggressive use of the
dynamic memory allocation, which allowed increasing the computational speed,
the size of processed data and the model complexity. Several graphic features were
improved during the year, and new Import/Export model formats Surfer ® and
GeoQuest ® , which were added to the existing ones (GoCad ® and Jason
Geosystems ® ). The software installation was made easier and its documentation
significantly extended. A particular effort was spent for the software porting for all
major Linux distributions (Slackware, Red Hat, Mandrake, Caldera, Debian) in
low-cost personal computers; of course, the Cat3D package runs also in different
hardware platforms (as IBM, Sun and SGI) under the Unix operating system.
Furthermore, we added a user-friendly menu for defining grids with a circular
symmetry, which we prepared and tested for 3D VSP’s.
Cover image of
the user manual for
the tomographic
Cat3D package.
33

Joint 3D inversion of P, S and converted waves
A. VESNAVER
G. ROSSI
During the last few years, ocean-bottom cables (OBC) were used at a large scale for
3D marine surveys for recording the three components of the particle velocity and
the pressure waves. Also on land surface surveys and in VSP’s this technology is
expanding, since it allows detect and separate P, S and converted waves. P and S
velocity and, in particular, their ratio, are important lithological parameters to
reconstruct porosity and pore pressure in the rocks. This information is important
to delineate boundaries and preferential migration paths both in hydrocarbon
reservoirs and in shallow water-saturated rocks.
In most cases, rock interfaces reflect both P and S waves, and convert part of their
energy from one wave type into the other one. When these events are observable
and can be reliably picked, we can enhance a lot the 3D lithological description of
the Earth, because of the data redundancy with respect to the estimated
parameters. In fact, the unknowns describing the interfaces do not increase, and
those ones for the velocities just double; viceversa, if P, S, P-S and S-P waves are
available, including both reflected and head waves, the traveltime data increase by
a factor much larger than two. Thus, the Earth model is much better constrained
by the experimental data, and more robust with respect to errors in the
traveltimes.
The joint inversion of P, S and converted waves has an additional advantage. The
sought velocity fields of P and S waves are almost decoupled, when considering
pure P and S arrivals: their only connection are the possible common reflecting
interfaces in the Earth. Converted waves provide new equations in the tomography
inversion, which directly relates the two velocity fields.
We set up a software prototype for the elastic inversion by generalizing our
previous acoustic code. The ray tracing algorithm is based on the Fermat’s
principle, and determines the ray path for a given ray signature by a bending type
approach. For example, in a P-S converted wave, we use the P velocities up to the
conversion point, where we switch to the S field, for computing and minimizing
the traveltime along the ray path. The P and S velocities are estimated by an ART,
SIRT or weighted SIRT algorithm.
Time-lapse 3D tomography
A. VESNAVER
F. ACCAINO
G. DAL MORO
G. MADRUSSANI
G. ROSSI
The response in a seismic survey over a producing hydrocarbon reservoir changes
during the years, due to the different pressure conditions of gas and the
movements of the gas/oil/water interfaces. This information is crucial for
optimizing the hydrocarbon production, locating the new wells in the unswept
areas, and where the hydraulic conductivity is expected to be adequate, as in
fractured or permeable formations. The 4D-TAIL Project is aimed at detecting
these variations of lithologic parameters by Amplitude Versus Offset (AVO) analysis
and 3D tomographic imaging. The OGS partners are two oil companies, i.e.
TotalFinaElf UK and Norsk Hydro, and the University of Milan. This project is
supported by the European Union in the Thermie Programme.
34

The joint inversion of
direct, reflected and
refracted P waves
allows reconstructing
the velocity and depth
in a model (above)
without any
redundancy, unlike in
the elastic case (below).
For a proper comparison of the differences in the seismic response, one has to
compensate all changes that do not depend on the reservoir itself, as the recording
geometry and equipment. A factor usually neglected that we studied is the seasonal
variation of the seawater velocity, due to changing currents and the temperature
of the mixed layer. These variations can be of the same order of magnitude (or even
larger) than those expected at the reservoir; furthermore, since they are spatially
organized, they can be attributed to the reservoir, so totally distorting the timelapse
analysis. In the Figure, we see that two 3D surveys acquired at the North sea
in 1989 and 1992 provide very different estimates for the sound speed in the sea
water, obtained by the joint inversion of reflected and head waves. (We remark that
these plots can be quite interesting for oceanographic studies too).
Outside the reservoir, we do not expect variations of the seismic velocities and the
reflector structure. Thus, we can impose that the Earth model in depth, obtained
35

from different data vintages, is unique. At the reservoir, the P and S velocities
should not be constrained at all, because their variations (and the resulting ratio)
is the primary information that we are looking for. Thus, we will have a set of
coupled models, one of each vintage year, that are mostly identical, except in the
upper layer and at the reservoir. When a proper amplitude-preserving surfaceconsistent
processing is carried out, including a vintage cross-calibration, we can
carry out a pre-stack depth migration of each vintage, and compare the reflectivity
changes at the reservoir. AVO can add further details, and guide the design of the
tomographic grid.
Sound speed in the seawater estimated by the joint inversion of
reflected and head waves in the year 1989 (above) and 1992 (below)
in the same area at the North Sea.
Seismic tomography for environmental studies
G. ROSSI
F. ACCAINO
G. BÖHM
G. DAL MORO
G. MADRUSSANI
M. PERONIO
A. VESNAVER
The oil and gas industry pushed seismic technology at advanced levels by
significant investments, which rarely are available for environmental studies.
However, except for a scale factor, many practical problems encountered in
hydrology within the shallowest Earth layers are very similar to those ones
considered in the hydrocarbon reservoirs. Seismic tomography is a possible
example: the inversion of velocity anomalies can be generally related to lateral
facies variations of the geological formations and, sometimes, to variation of other
properties of hydraulic interest – as permeability and porosity. If both P and S
waves can be jointly inverted, various analytic expressions exists which related
these velocity fields to the fluids’ pressure and saturation.
36

Transferring technology from the oil and gas industry to environmental
application is a goal we pursued within the MICA Project, funded by the “Fondo
Trieste”. We acquired a high-resolution 3D survey close to the Trieste airport, in an
area where the city aqueduct has several catchment wells. The tomographic
inversion and imaging of this data showed not only a good correlation with the
available stratigraphy from 3 wells, but also remarked the significant vertical and
lateral variations of the layers overlying the water-saturated formations. This fact
proves the viability of 3D surveys for the protection of groundwater from pollution,
and also their need: sparse 2D profiles would miss the area complexity;
furthermore, drilling sparse exploration wells would be not only even less
significant (and probably more expensive), but could break the impermeable
covers over the groundwater pool, allowing it to be polluted by industrial or
agricultural activities.
Complementary to the seismic surveys, we carried out also a Georadar and a geoelectric
survey, for integrating the elastic and electro-magnetic parameters. Of
course, the penetration scale of the different techniques is quite different (but
complementary), and their integration into a consistent physical model is
ongoing. Partner of OGS within the MICA Project is GeoKarst, which is a
geochemical company located in the Trieste Area Science Park. This company is
complementing the OGS activity by analyzing the water origin and fluxes by
measuring the isotopes it contains.
The stratigraphy
of 3 water well (above)
matches the pre-stack
depth migrated section
(below) obtained by
tomographic velocities
in a high-resolution
3D survey.
37

Geophisical interpretation
Coordinator: Angelo CAMERLENGHI
The activity of the group in 2000 was characterised by intensive data acquisition at
sea and on land. At the same time data processing and interpretation have been
carried out in the OGS headquarters. Data acquisition, focussed to the
understanding of the geology of continental margins, was mainly in Antarctica,
within the projects WEGA (Wilkes Land Glacial History), LARSEN (Deglacial
History of the Larsen Ice Shelf - Weddell Sea), ODP Leg 188 in Prydz Bay
(M. Rebesco was shipboard sedimentologist), and TESAC (Tectonic and Cenozoic
Evolution of the South America-Scotia Plate Boundaries) sponsored by PNRA. In
addition, we participated in a cruise of the EU project STRATAGEM
(Stratigraphical Development of the Glaciated European Margin) on the Faroe-
Shetland margin. The data we collected span from single and multi channel
seismic reflection, chirp sonar, core logging data, gravity at sea, to structural
geology data and lake bathymetry on land. Of particular relevance for the group
was the continuing activity with the recently acquired Geotek multi-sensor core
logger, and the utilisation of the Datasonic chirp sonar in Antarctica.
Processing and interpretation were on seismic, gravity, magnetic data, core
samples, core logging, downhole logging, and oceanographic data collected in the
previous years within the research programs sponsored by PNRA on the Pacific
Margin of the Antarctic Peninsula (Projects ODP Leg 178, SEDANO, Sediment
Drifts of the Antarctic Offshore, and BSR, Bottom Simulating Reflectors), in the
South Scotia Sea (Crustal Structure and Evolution of the Powel Basin), and in the
Ross Sea (Cape Roberts Drilling Project and Evolution of the West Antarctic Ice
Sheet). Research was conducted with the highest possible level of international
cooperation and by supporting research fellowships at other research institutions
such as INGV, Rome, and the University of Trieste.
The research activity involving the processing of Synthetic Aperture Radar (SAR)
satellite images has continued with applications to areas such as Antarctica, Tierra
del Fuego and the surroundings of city of Trieste. In parallel, we started a new
project as a joint venture with SOPROMAR in a contract with the Italian
Geological Survey to produce test sheets of the marine gravity maps of the coastal
zones of Italy.
In the field of environmental geology and geophysics, we participated in research,
within broader OGS projects, on the aquifers identification and mapping in the
Friuli Venezia Giulia region. Another project has involved the identification of
karstic cavities with micro-gravimetric techniques.
Research applied to petroleum exploration included one project funded by AGIP on
the kinematics of salt deformation in the Eastern Mediterranean and distal Nile
cone (in cooperation with the University of Parma and IGM, Bologna), and the
participation in the Ormen Lange Verification project sponsored by NorskHydro
through SINTEFF on the theme of gas hydrates.
38

At the end of the year, we started a doctoral Program in Polar Sciences (applied to
polar continental margin evolution) in cooperation with the University of Siena.
Michele Rebesco hosted the Workshop “Seismic expression of contourites
and related deposits” in the framework of the IUGS-UNESCO International
Geological Correlation Programme n. 432 (Contourites, Bottom Currents and
Palaeocirculation).
We illustrate below the major scientific results achieved in the year 2000.
Joint Italian/Australian Marine Geoscience Expedition
to the George V Land Region of East Antarctica
(Wilkes Land Glacial History, WEGA project)
G. BRANCOLINI
M. BUSETTI
C. PELOS
L. SORMANI
R. VIDMAR
A collaborative Italian PNRA/Australian AGSO-Antarctic CRC marine geoscience
research voyage to the George V Land sector of the East Antarctic continental
margin was carried out in February-March, 2000, on board the of the RV Tangaroa.
A total of 1827 km of multi-channel seismic data (2 x 150 cu.in. GI airguns, 600 m
streamer length), 562 km of Chirper (2.5-7kHz and 8-21 kHz transducers, 1000m
armoured cable) sonar data, 11 gravity cores, 28 piston cores, 18 surface grabs and
11 short trigger cores were collected on the voyage. Water profile (CTD)
measurements and water samples were collected at nine stations and seabed
bottom photographs were made at 11 stations.
The expedition discovered and mapped a shelf current-derived, sediment drift
deposit called the “Mertz Drift”, covering about 400 km 2 lying in an >800m deep
section of the George V basin west of the Mertz Glacier.
On the continental rise multi-channel seismic data were taken across contourite
drift deposits and a submarine canyon system in 2500 to 3500 m water depth.
Piston cores were collected along the profile of one drift deposit which gave a
preliminary Mid-Pliocene age to truncated strata that crop out on the drift’s
steeper lee side. These data will provide crucial information about the Antarctic
late Cenozoic glaciations and useful site-survey support of a proposal sent to the
Ocean Drilling Program under the auspices of the SCAR-ANTOSTRAT project for
drilling key sites along the Antarctic margin.
Deep Tow Chirper profile W-16 in the George V basin (continental shelf) and
core stations across the “Mertz Drift”. The drift is over 35 m thick and it is composed
of laminated, anoxic, gelatinous olive green, siliceous mud and diatom ooze (SMO).
39

Physical properties and seismic stratigraphy of ODP
Leg 178 well sites, Antarctic Peninsula Pacific margin
V. VOLPI
A. CAMERLENGHI
M. REBESCO
P. CORUBOLO
U. TINIVELLA
C. DE CILLIA
In this work, sponsored by PNRA as participation to the scientific activity of the
Ocean Drilling Program, we have re-analysed the porosity, bulk density and
seismic velocity information collected from three bore holes on the continental
rise of the pacific Margin of the Antarctic Peninsula. The purpose is to provide a
comprehensive, composite digital data set of data readily available for future
studies aimed at well-seismic correlation. The work originates from the
occurrence of overlapping sets of physical parameters and acoustic velocity
collected with different methods (downhole logging, core logging, laboratory
determination, derivation from seismic data), and in different holes of the same
site. These data not always provide the same information.
Composite vertical profiles of velocity (sonic logs, core logs, and measurements on
samples), density (RHOM - LDS corrected bulk density) and porosity (APLC - APS
Near/Array limestone porosity corrected) have been obtained by combining data
from different instruments and different holes. The comparison between core and
log porosity for site 1095 shows that, except for the lower part of the section,
downhole porosity is systematically larger than core sample porosity due to
the poor open hole conditions encountered in a fine grained, generally
underconsolidated formation.
At site 1095 additional information on acoustic velocity comes from the velocity
check-shots, obtained from a vertical seismic profile (VSP), while at site 1096
additional information comes from acoustic tomographic inversion of travel times.
These interval velocities can be compared with the nearest available stacking
velocity and the velocities obtained from core samples, at site 1095. The in situ
velocity check-shots provide a more reliable velocity information than the stacking
velocity throughout the section, while the vertical seismic profile (VSP) provides a
reliable tie to the site survey MCS.
40

ODP Leg 178 - Site Location
Site 1095 Porosity
(g/cm 3 )
A
B
Site 1095 Line 195-135A Site 1095
NW
SE
mbsf
TWT time (s)
interval velocity (m/s)
C
D
A) Location map of ODP Sites 1095, 1096, and 1101 (highlighted), together with all
other sites drilled during ODP Leg 178. B) Comparison between the downhole
logging (APLC, APS Near/Array limestone porosity corrected) porosity (red curve )
and porosity from the index properties (IP) measurements in the laboratory.
C) Comparison among interval velocities obtained with the in situ velocity check
shots (VSP), stacking velocities and core log velocity. D) Vertical Seismic Profile and tie
in two way travel times between lithostratigraphic and seismostratigraphic units.
41

Orbitally-Controlled rhythmic sedimentation
in the Wild Drift, Antarctica (ODP Leg 188, Site 1165)
M. REBESCO
This research, conducted in collaboration with J. Gruetzner (Bremen University,
Germany) is an outcome of the participation of an OGS researcher (Michele
Rebesco) to the ODP Leg 188 in Prydz Bay – Cooperation Sea (Antarctica). Leg 188
cruise began in Fremantle (Australia) on 10 January 2000 and ended in Hobart
(Australia) on 11 March 2000. Three sites were drilled on continental shelf, slope
and rise to document onset and fluctuations of East-Antarctic glaciations.
Site 1165 is situated in a water depth of 3357m on the continental rise in front of
the outlet of the Lambert glacier-Amery Ice Shelf system that today drains 22% of
East Antarctica. The site cored a 999-m lower Miocene-Holocene section into an
elongate sediment body (Wild Drift) formed by the interaction of westward-flowing
currents with the sediment supplied from the shelf. Alternations with wavelengths
ranging from cm to m size between a greenish grey diatom bearing clay facies and
dark grey clay facies with silt laminations are apparent throughout the hole back
to early Miocene time. Furthermore the greenish intervals are characterised by
lower density, susceptibility and iron content. The dark grey intervals are
interpreted as contouritic facies deposited during maximum ice advances whereas
the greenish sediments indicate hemipelagic sedimentation under warmer climate
conditions.
Analysis of high resolution colour photo-spectrometer data reveals that the colour
cycles are best described by the ratio of the reflectivity in the green colour band
and the average reflectivity (grey).
Spectral analyses on depth and time series of the investigated parameters over
selected intervals demonstrate that variance is dominated by orbital frequencies as
predicted by the Milankovitch theory. The detected obliquity and precession cycles
allow a refined evaluation of sedimentation rates.
Subsidence at the Cape Roberts drill sites
(Ross Sea, Antarctica) from backstripping techniques
L. DE SANTIS
G. BRANCOLINI
The tectonic subsidence of the western margin of the Victoria Land basin has been
estimated from the physical properties and ages of the sediments in the Cape
Roberts Project drill cores 2/2A and 3, using backstripping techniques, assuming a
local isostatic compensation. The sediment load effects is removed from the total
subsidence and the tectonic contribution through time at each location is
calculated.
The analysis indicates a total tectonic subsidence of about 660 m at this location
between 34 Ma and the present time. Two main trends are defined, i) about 230
m/m.y. from 34 Ma to 32.5 Ma, and ii) about 23 m/m.y. from 32.5 Ma to 21 Ma.
Since 21 Ma, the subsidence is not well constrained. Extrapolation indicates a very
low subsidence rate, but uplift within this period may have greatly affected the
estimate.
42

Core 1165B-14H
Composite diagram showing the cyclicity at different scales nested together in the
colour record from Core 1165-14H. The cm-scale cycles are evidenced by colour
banding and lamination (see the interpreted black and white photo in the left
bottom). Such cycles are included within dm-scale cycles evidenced by lighteningup
intervals. In turn, these cycles are included within dark grey facies (see the black
and white photo in the centre and the synthetic interpretation on its right). Finally
m-scale cycles are constituted by a couplet of dark grey and greenish grey facies.
The dm- and m-scale cycles are precisely recorded by colour photo-spectrometer
data (see the ratio of the reflectivity in the green colour band versus the average
reflectivity on the right side of the diagram). Moreover (not shown here) larger
scale (tens to hundreds of m) cycles are produced by the variation in ratio between
the thickness of the two facies of the m-scale couplets.
43

The age and the calculated fast rates of the tectonic subsidence affecting the
western Ross sea until 21 Ma is consistent with previous studies made in the
Central and Eastern Ross Sea that suggest an Oligocene age of the basin opening
phase in those regions. Since 20 Ma, extrapolation of the tectonic subsidence
curves indicates a period of very low subsidence. Seismic reflection data across the
VLB indicates that extensional tectonics was diachronous within the VLB and it
was progressively younger toward east and possibly toward south. We believe that
the apparent major slow down of the overall subsidence rate after about 20 Ma may
be the result of subsequent uplift of the region and migration of the extensional
tectonics toward east and south.
A
TECTONIC SUBSIDENCE
A. Tectonic subsidence curves obtained
using backstripping technique at the CRP-2
(squares) and the CRP-3 (circles) drill sites.
The dashed curve represents the
extrapolated tectonic subsidence of the
basement at CRP-3 site between 31 Ma
and present. This curve is inferred from the
trend at CRP-2 (from 30 to 21 Ma) and the
depth of the basement caused by the
tectonics at present time at the CRP-3 site.
The error bars indicate the range of the
uncertainties in the paleo-depth
information and age.
B. line drawing of a composite seismic
section made by IT69, US 403 and US 404
across the VLB about 5 km north of the
CRP drill sites.
WEST
EAST
B
44

Cenozoic Evolution of the South Orkney Microcontinent
M. BUSETTI
A. MARCHETTI
The South Orkney Microcontinent is one of the fragments of the South Scotia
Ridge between the Antarctic and Scotia Plate. It is a key area for both Cenozoic
paleoclimatic and geodynamic studies as it is a remnant of the separation between
Antarctica and South America about 26 Ma. The separation permitted the onset of
the Circum-Antarctic current and the following climate isolation of the Antarctic
continent.
Due to the complexity of the geodynamic setting of the area and the different
tectonic regime (transform, convergence and divergence) in the surroundings, the
small microcontinent has complicate geological evolution. Basins formation on
the microcontinent is related to the South Scotia Ridge fragmentation in the
?Eocene/Oligocene time. The northern margin of the South Orkney
Microcontinent is an obliquely convergent plate boundary dominated by
transcurrent condition exhibiting strain partitioning of convergent motion
accommodating by a thrust zone in the oceanic area and vertical strike-slip zone
at the border of the steep escarpment of the SOM. Between the microcontinent and
the Bruce Bank the plate boundary changes, exhibiting transcurrent and
extensional regime.
Structural scheme of the South Orkney Microcontinent and bathymetric
contours of the area. The continental shelf of the microcontinent is delimited
by the 1000-meter contour. Extensional tectonic in the Eocene/Oligocene time
produced several north-south elongated basins. The northern margin of the
microcontinent is the plate boundary between Antarctic and Scotia Plates.
45

Structure and Cenozoic evolution of the South America –
Scotia plate boundary in the Tierra del Fuego region
E. LODOLO
R. GELETTI
Onshore field geological and geophysical studies, and a multichannel seismic
survey have been conducted in the last two years in the Tierra del Fuego region, in
the frame of an Argentinean-Italian scientific research. The main aim of this
project was to analyse the regional geological setting of the Island and reconstruct
the Cenozoic geodynamic evolution of an important segment of the South
America-Scotia plate boundary, called Magallanes-Fagnano fault system. This is a
mainly wrench lineament which cuts across the Island and runs from the Pacific
entrance of the Magallanes Strait to the Atlantic coast of the Island. The Lago
Fagnano, located in the central part of the Tierra del Fuego, is an E-W-trending
major depression which hides part of the fault, as revealed by the bathymetric map,
which shows the presence of significant and steep scarps in correspondence of the
onshore prosecution of the lineament. In cross-section, this tectonic lineament is
represented by sub-vertical faults and associated asymmetric basins, generated by
simultaneous strike-slip motion and transform-normal extension, as imaged by
the seismic profiles acquired off the Atlantic coast of the Island and in the central
and western Magallanes Strait.
Data analyses support the interpretation that the Magallanes-Fagnano fault system
is remarkably transtensive in nature, and is structurally and temporally
superposed on the older tectonic framework of the Tierra del Fuego (i.e., the
contractional system of the Magallanes fold and thrust belt), even if the
displacement history of this fault system is unclear. The near parallelism among
the younger and older lineaments suggests that the development of the
transtensional structures may have reactivated pre-existing weakened zones
formed by the Cretaceous-Tertiary shortening.
Mapping the BSR on the South Shetland Margin
(Antarctica) and assessing gas hydrate and free gas
quantities
E. LODOLO
A. CAMERLENGHI
G. MADRUSSANI
G. ROSSI
U. TINIVELLA
Bottom Simulating Reflectors (BSRs) along the South Shetland continental
margin have been first identified by OGS researchers on two multichannel seismic
profiles acquired by the R/V OGS-Explora (1990 Antarctic Campaign). A dedicated
survey was conducted on 1997 to purposely map the extent of the BSR on this
margin, and study the relationships between geological structure and gas hydrate
and free gas distribution. Processing and interpretation of the collected grid of
high-resolution multichannel seismic reflection profiles have been completed
(about 700 km of data), and have allowed us to map the lateral extent of the BSRs.
The South Shetland continental margin, an accretionary wedge located off the
northern tip of the Antarctic Peninsula, consists of two distinct and superimposed
tectonic regimes: an older regime is related to Mesozoic - Middle Cenozoic
subduction-related tectonism; a younger one is associated with a mainly
46

Magallanes-Fagnano
master fault
TWT (s)
Tectonic sketch of the Magallanes-Fagnano fault system across the
Tierra del Fuego Island, as revealed from the interpretation of seismic
profiles acquired at the Pacific entrance
of the Magellan Strait (section A), in the central part of the Strait
(section B), and off the Atlantic coast of the Island (section C).
The profile on the right (section C) shows the presence of a principal
sub-vertical fault (the master fault), with associated asymmetric
basin, generated by simultaneous strike-slip motion and transformnormal
extension along the strike of the fault system.
47

extensional tectonic phase, and related to the Oligocene development of the
western Scotia Sea. The occurrence of the BSR appears to be controlled by the
geological structure of the margin. The BSR lacks continuity near basement
structures, main geological discontinuities and faults. On the contrary, the
amplitude and continuity of the BSR are not affected by the presence of folded
structures and undeformed sedimentary layering. We found that the BSR is mostly
confined to the N-E sector of the South Shetland Margin, where propagation of
faulting associated to the Shackleton Fracture Zone may have driven migration of
natural gas towards the surface and created the conditions for a BSR to appear. The
application of reflection tomography techniques allowed us to reconstruct the
averaged seismic velocity field between the seafloor and BSR in order to map the
depth of BSR. By averaging the observed velocity structure above and below the
BSR, and applying a theoretical model of elastic wave propagation in porous media,
we attempted as rigorously as possible a quantitative assessment of the natural gas
present as gas hydrate above the BSR and as free gas between the BSR and the Base
of Gas Reflector (BGR).
We found that in this reservoir, where free gas layers are widespread and of
significant thickness, the amount of free gas trapped beneath the gas hydrate layer
is about two orders of magnitude less than the natural gas stored as hydrate phase.
The obtained values, compared with global estimates of total natural gas trapped
in and beneath gas hydrate reservoirs proposed by several authors, represent
1/10000 of the global estimate and are about twice that estimated in the Prudhoe-
Kuparuk oil field (Alaska), and one order of magnitude less than the Bering Sea
reservoir, which extends however over an area extremely larger than the South
Shetland margin reservoir.
Gas hydrate physical properties imaging by multi-attribute
analysis - Blake Ridge BSR Case History
F. COREN
V. VOLPI
U. TINIVELLA
In this project, partially supported by the European Union under the project
‘Application of Seismic Attribute Analysis for Reservoir Characterisation’ (CEE/NIS
(INCO/COPERNICUS 1995 – 1996), we analysed the Bottom Simulating Reflector
(BSR) of the Blake Ridge (Figure A) through the “multi-attribute” analysis, by
using the EMERGE (Hampson – Russel) software. This technique allows
prediction of petrophysical/geological parameters along seismic lines (velocity,
porosity, density, resistivity etc.) starting from log data. Its application consists of
three steps: i) tie the well log to seismic data; ii) train the seismic to predict the
reservoir parameter of interest at the tie locations and iii) apply the result of the
training to the seismic dataset. The algorithm that allows the correlation between
logs and seismics is the generalised multiple linear regression. The resulting
function is then applied to the seismic profile, generating a target log-predicted
section. We obtained five sections (VSP and P-wave velocity, density, porosity and
resistivity), each of them representing the distribution of the corresponding
property along the profile. The data set is constituted by two seismic lines and
48

(Top): Structural map
of the BSRs occurrence
along the South
Shetland margin,
where the differences
in strength of the BSRs
have been highlighted.
(Bottom): Part of a
seismic profile where
the BSR crosses an
anticline fold, without
loss in amplitude and
strength.
W
E
49

three wells in the Blake Ridge, offshore southern United States. Here, a strong
‘BSR’ marks a transition from a hydrate rich sediments zone above, to a free gas
bearing sediments below. This transition is reflected in the velocity profile with a
boundary at 4150 ms between a high velocity region (1670 m/s above) and a low
velocity one (1500/1600 m/s below) (Figure B).
A velocity structure obtained by prediction can be translated in gas hydrate and
free gas concentration structure. We used the method proposed by Tinivella
(1999). The concentration is estimated by fitting the theoretical velocity to the
experimental P/wave velocity (derived by the prediction of the VSP in our case).
The discrepancies between the inverted velocity profile and the velocity for water
filled marine sediments are interpreted as due to the presence of the gas hydrate
(where positive anomalies are present) and free gas (where negative anomalies are
present). Figure C shows the distribution of the two phases: positive values (red
colours) are the gas hydrate concentration, while negative concentrations (blue
colours) are related to the percentage of volume occupied by free gas.
A
VSP velocity Section
B
A) Position map of the
study area. Wells
location and seismic
line position are shown
in the close-up
window.
B) VSP velocity panel.
C) Distribution of the
two gas phases;
positive values (red
colours) are the gas
hydrate concentration,
while the negative
concentrations (blue
colour).
C
50

Physical properties of sediment cores
from the Antarctic continental margins
M. BUSETTI
Antarctic paleoclimate and paleoenvironmental studies have a key role in the
understanding of the global climate changing. Waxing and waning dynamic of the
Antarctic ice coverage is the most important effect at high latitudes as response to
climatic variations. As sediment deposited on the continental shelf and rise record
the ice fluctuations, they are an essential task in the paleoclimate study. Analysing
the acoustical and physical properties of sediment cores it is possible to investigate
glacial and interglacial stages. P-wave velocity, bulk density and magnetic
susceptibility are closely related to sediment composition and may reflect changes
in grain-size distribution or in the ratio of terrigenous (quartz and clay) and
biogenic components. Generally terrigenous sediment characterise glacial
deposits, while biogenic material is present in the interglacial deposits.
Acoustical and physical property logs of a marine piston core collected on the
continental rise of the Antarctic margin. P-wave velocity and bulk density reflect
the grain size distribution: the higher values in the upper part of the core are
related to silt, and even greater to sand, the lower values in the deeper part
of the core are related to the clay fraction. Ice rafted debris (black spots in the
visual log) produce clear spikes in the magnetic susceptibility measurements.
51

Backstripping modelling in the frame of the
Stratigraphical Development of the Glaciated European
Margin (STRATAGEM) - EU project
L. DE SANTIS
S. CERAMICOLA
A. CAMERLENGHI
The Project is funded by the European Community within the 5 th framework and
it is part of the Ocean Margin Deep Water Research Consortium (OMARC) cluster.
It is Co-ordinated by Dan Evans (British Geological Survey, UK).
The principal objectives of STRATAGEM (web site: www.stratagem-europe.org) are
to address problems related to the mid-Cenozoic to Recent development of the
glaciated north European margin, that extends from northern Norway to central
Ireland. The end product of the project will be the development of a Margin
Evolution Model, to assess the interactions of sedimentary processes that have
produced the character of the present day margin and the forcing factors (such as
climate, tectonics and palaeoceanography).
The seismic data to be interpreted will comprise existing data held by the partners,
new data to be acquired in STRATAGEM, and data from industry, and from the
IMAGES project.
The OGS INTE group contributes to the project in:
1) 300 km of Single channel (90 in 3 GI gun, 16 m streamer length) seismic data
collection (and processing) in the Faroe Island continental margin (R/V DANA
cruise);
2) 2D flexural, post-rift backstripping modelling on several transects along the
length of the continental margin, in particular in the Vøring, in Shetlands-
Faroe Islands and in the Hebrides margins. The models will constrain the
more-qualitative Margin Evolution Model, and provide insights into factors
such as uplift and subsidence that have been among the crucial controls on
margin development. The observed stratigraphy is modelled using flexural
backstripping combined with decompaction and reverse thermal subsidence
calculations by mean of a commercial software package (Flex-Decomp by
Badleys Ltd.-UK). Reliable direct palaeobathymetry information from drill sites
and indirect palaeobathymetry markers, such us erosion surfaces, are used to
constrain the subsidence history. During the first year of the project several
tests have been carried out to verify the input parameters (e.g. stretching factor
and the lithosphere elastic thickness).
3) the comparison with the Antarctic glaciated margins, that will place the results
of the STRATAGEM study in a global perspective.
52

Bathymetric map of the North Atlantic continental margin studied in the STRATAGEM
frame. WP1 is the Work Package 1 study area (the Norwegian margin); WP2 is the Work
Package 2 study area (the South Shetland-Faeroe margins); WP3 is the Work Package 3
study area (the Rockall Trough and Porcupine Basin).
Earth gravity field: measurements, data processing
and interpretation
C. ZANOLLA
F. PALMIERI
F. COREN
C. DE CILLIA
OGS has a long tradition in gravimetry (i.e. the international gravity station
network IGSN71, Italian gravity map, marine gravity surveys in the Mediterranean
sea). Gravity surveys (land or marine) can be managed from planning, to field
acquisition, processing and interpretation. The INTE group has the responsibility
to manage and operate three LaCoste-Romberg gravity meters (one model D and
two model G), one underwater gravity meter LCR model H, one marine surface
gravity meter Bodenseewerk KSS31. These allow us to cover all the possible
applications of gravimetry:
At present our group is involved in the following projects:
1) A joint venture group OGS and SO.PRO.MAR has been entrusted by Servizio
Geologico Nazionale to carry out two marine gravity surveys in areas located
near Rome.
53

The purpose is to merge the land and marine gravity data to obtain a higher
spatial definition of the gravity anomalies near the coastline and a gravity map
that is overlapped with the geological maps at scale 1:50.000. In particular we
have been required an underwater gravity survey and a surface marine gravity
survey. The first survey has been completed while the second one will be
carried out in february 2001.
2) Two micro-gravimetry nets have been established in order to study the
temporal gravity variations associated with: a) water table fluctuations to study
the effective porosity of the geological formations involved (Fagagna area); b)
the subsidence problems that affect some districts of the city of Trieste; this
survey is jointly carried out with SAR techniques.
In the near future we will repeat measurements in a network located in
seismically active areas of Friuli-Venezia Giulia.
3) Several micro-gravity surveys have been planned in order to detect the
presence of cavities in the Carso area surrounding the city of Trieste: One
survey is ongoing in the “Grotta Doria”, with the aim to model the gravity
anomalies and to compare the results obtained with several geophysical
techniques applied to the same geological feature.
4) Our group is active also in data Antarctica were we acquired a gravity transect
(see Figure) crossing the Wilkes Basin (East Antarctica).
AHVRR image of
Antarctica with
superimpose the ITASE
traverse along which
the gravity profile has
been acquired (above).
Free air gravity profile
acquired across the
Wilkes Basin, East
Antarctica (below).
Free Air gravity anomaly (mGal)
54

Synthetic Aperture Radar (SAR) remote sensing
F. COREN
R. VIDMAR
P. STERZAI
Horizontal velocity
field of the
Ligosullo landslide
(northeast Italy)
derived by SAR
interferometry
(yellow contours)
superimposed
to a aerial
image of the area.
Since 1996 OGS developed within the INTE group its own research line in
Synthetic Aperture Radar (SAR) remote sensing. The activity is now mainly
addressed to interferometry and analytical products generation using ERS-1 and
ERS-2 satellites.
Research activity have been focused on two main tasks:
1) Monitoring terrain deformation (landslide) using differential interferometry
techniques and analysis of the hydrological setting using SAR remote sensed
data. In this field TS-SAR is the major project where SAR interferometry has
been used to monitor ground deformation in the area of Trieste (Italy) in the
period between 1996-2000 for the Civil Protection Department of the
Municipality. A specific investigation has been carried out in industrialised and
urban area to assess the possibility of a continuous monitoring of inferred
subsiding phenomena. A set of complex interferograms has been computed in
order to identify sliding and subsiding areas and to verify the general urban
stability. A validation procedure on the interferogram has been applied
considering only pixels characterised by high coherence in all the
combinations. These pixels represent permanent backscatter and are mainly
associated to civil structures and buildings. The displacement history of three
warehouses has been computed on the temporal basis of 23 month. At the
present, a validation has been carried out only by ground observation without
elevation measurements. Other minor project has been also carried out to
monitor and detect landslides in the Friuli area (see figure).
2) Study of the glacial setting of East Antarctica (STARGLASS project financed by
PNRA Italian National Antarctic Program) and Northwestern sector of
Antarctic Peninsula (a self sustained research activity). Main goal of both
projects is the computation of the ice velocity fields and digital elevation model
of outcrop areas. Polar regions play an important role in the global
environment. The potentiality of
SAR interferometry for the
monitoring of high latitude areas is
today a well understood geophysical
tool and represents a flexible and
powerful method to study large polar
sectors at low specific cost. In
STARGLASS project we have used
pairs of tandem images of satellites
ERS-1 and ERS-2 synthetic aperture
radar (SAR) of the David glacier, East
Antarctica, for the purpose to outline
the grounding line. All the SAR radar
data have been provided under the
VECTRA project cover (European
Space Agency Announcement
Opportunity 3.108) in raw format.
55

Administration
Coordinator: Dario Colonnello
F. PETRONIO
The activities of the administration office were, basically, to manage the purchase of
raw material, scientific instruments, services and consumables necessary to carry out
the various projects; personnel expenses for traveling to working sites and scientific
meetings and conventions; invoices and statements of accounts and the legal aspects
of the projects; and the Department’s inventory.
The total turnover of the Department in 2000 was approximately 3.7 milion Euro’s of
which we effectively spent 1.7 milion Euros. The real income related to specific
programs amounted to more than 3.2 milion Euros.
56

Publications
Wave modeling
ARNTSEN, B., AND CARCIONE, J. M., 2000, A new insigth into the reciprocity principle,
Geophysics, 65, 1604-1612.
ARNTSEN, B., AND CARCIONE, J. M., 2000, Numerical simulation of the Biot slow wave
in water-saturated Nivelsteiner sandstone, submitted to Geophysics.
CARCIONE, J. M., ARNTSEN, B., AND CAVALLINI, F., 2000, Simulation of ultrasonic waves
in a natural sandstone. In Bermudez, A. et al. (Eds.), Mathematical and Numerical Aspects
of Wave propagation, SIAM, 128-132.
CARCIONE, J. M., AND SERIANI, G., 2000, Numerical simulation of wave propagation in
frozen porous media. In Bermudez, A. et al. (Eds.), Mathematical and Numerical Aspects
of Wave propagation, SIAM, 771-775.
CARCIONE, J. M., GUREVICH, B. AND CAVALLINI, F., 2000, A generalized Biot-
Gassmann model for the acoustic properties of clayley sandstones, Geophys. Prosp., 48,
539-557.
CARCIONE, J. M., AND GANGI, A., 2000, Non-equilibrium compaction and abnormal porefluid
pressures: effects on seismic attributes, Geophys. Prosp., 48, 521-537.
CARCIONE, J. M., AND POLETTO, F., 2000, Sound velocity of drilling mud saturated with
reservoir gas, Geophysics, 65, 646-651.
CARCIONE, J. M., AND GANGI, A., 2000, Gas generation and overpressure: effects on
seismic attributes, Geophysics, 65, 1769-1769.
CARCIONE, J. M., 2000, A model for seismic velocity and attenuation in petroleum source
rocks, Geophysics, 66, 1080-1092.
CARCIONE, J. M., AND SCHOENBERG, M., 2000, 3-D ground-penetrating radar
simulation and plane wave theory, Geophysics, bf 65, 1527-1541.
CARCIONE, J. M., 2000, AVO effects of a hydrocarbon source-rock layer, submitted to
Geophysics.
CARCIONE, J. M., AND CAVALLINI, F., 2000, Abnormal pore pressure and Poisson’s ratio,
submitted to Geophys. Prosp.
CARCIONE, J. M., 2000, Amplitude variations with offset of pressure-seal reflections,
Geophysics, in print.
CARCIONE, J. M., 2000, Energy balance and fundamental relations in dynamic anisotropic
poro-viscoelasticity, Proc. Roy. Soc. London A, 457, 331-348.
CARCIONE, J. M., AND SERIANI, G., 2000, Wave simulation in frozen sediments,
J. Comput. Phys., in print.
CARCIONE, J. M., FELICIANGELI, L., AND ZAMPARO. M., 2000, The exploding-reflector
concept for ground penetrating radar modeling, submitted to Geophysics.
CARCIONE, J. M., AND TINIVELLA, U., 2000, The seismic response to overpressure: a
modeling methodology based on laboratory, well and seismic data, submitted to
Geophys. Prosp.
CARCIONE, J. M., CAVALLINI, F., AND MAINARDI, F., AND HANYGA, A., 2000, Timedomain
seismic modeling of constant Q-wave propagation using fractional
derivatives, Pure and Applied Geophysics, in print.
CARCIONE, J. M., AND CAVALLINI, F., 2000, A semi-analytical solution for the propagation
of electro-magnetic waves in 3-D lossy orthotropic media, Geophysics, in print.
CARCIONE, J. M., AND POLETTO, F., 2000, Simulation of stress waves in attenuating drill
strings, including piezoelectric sources and sensors, J. Acoust. Soc. Am., 108(1), 53-64.
CARCIONE, J. M., PADOAN, G., AND CAVALLINI. F., 2000, Synthetic seismograms of the
sea-bottom under different streamers conditions, Boll. Geof. Teor. Appl., 41, 21-29.
57

CARCIONE, J. M., AND HERMAN, G., AND TEN KROODE, F. P. E., 2000, Seismic
modeling, A review for Geophysics, submitted.
CARCIONE, J. M., AND GEI, D., 2001, A seismic modeling study of Vostok lake, submitted
to Journal of Glaciology.
CARCIONE, J. M., AND CAVALLINI, F., 2000, Poisson’s ratio at high pore pressure, Norsk
Hydro, E&P research centre, Bergen, NH-report R-089643.
CARCIONE, J. M., MARCAK, H., SERIANI, G., AND PADOAN, G., 2000, GPR modeling
study in a contaminated area of Krzywa airbase, Geophysics, 65, 521-525.
CARCIONE, J. M., AND TINIVELLA, U., 2000, A modeling study based on laboratory, well
and seismic data, Norsk Hydro, E&P research centre, Bergen, NH-report R-089737.
CARNEVALE, G.F., CAVALLINI, F., and F. Crisciani, 2000, Dynamic boundary conditions
revisited. J. Phys. Oceanogr., In press.
CAVALLINI, F., Reply to comment by K. Helbig on “The best isotropic approximation of an
anisotropic Hooke’s law” by F. Cavallini, Boll. Geof. Teor. Appl. 41, 1, 2000, 89-90.
CAVALLINI, F., AND CRISCIANI, F., A generalized 2-D Poincare inequality. J. of Inequal. &
Appl., 5:343-349, 2000.
GUREVICH, B. AND CARCIONE, J. M., 2000, Gassmann modeling of acoustic properties of
sand/clay mixtures, Pure and Applied Geophysics, 157, 811-827.
HANYGA, A., AND CARCIONE, J.M., 2000, Numerical solutions of a poro-acoustic wave
equation with generalized fractional integral operators. In Bermudez, A. et al. (Eds.),
Mathematical and Numerical Aspects of Wave propagation, SIAM, 163-167.
PHAM, N. H., CARCIONE, J. M., Helle, H. B., 2001, Poro-viscoelastic representation of
shaley sandstones, 63th Ann. Internat. Mtg. Europ. Assoc. Expl. Geophys., Expanded
Abstracts.
POLETTO, F., CARCIONE, J. M., LOVO, M., AND MIRANDA, F., 2000, Acoustic velocity of
SWD bore-hole guided waves, submitted to Geophysics.
POLETTO, F., AND CARCIONE, J. M., 2000, On the group velocity of guided waves in drill
strings, Submitted to J. Acoust. Soc. Am..
PRIOLO, E., 2000, Deterministic computation of the reference ground motion in Fabriano
(Marche, Italy). Ital. Geotech. J., in print.
PRIOLO, E., 2000, Earthquake ground motion simulation through the 2-D spectral
element method. J. Comp. Acoustics, in print.
PRIOLO, E., 2000, 2-D spectral element simulation of the ground motion for a
catastrophic earthquake. In: E. Faccioli and V. Pessina (Eds.), The Catania Project:
Earthquake Damage Scenarios for High Risk Area in the Mediterranean. CNR-GNDT,
Rome (Italy), 67-73.
PRIOLO, E., AND MICHELINI, A., 2000, Measurments of environmental seismic noise for
site response prediction. In: E. Faccioli and V. Pessina (Eds.), The Catania Project:
Earthquake Damage Scenarios for High Risk Area in the Mediterranean, CNR-GNDT,
Rome (Italy), 73-75.
TINIVELLA, U., AND CARCIONE, J. M., 2000, Estimation of gas-hydrate concentration and
free-gas saturation from log and sesimic data, The Leading Edge, in print.
SERIANI, G., 2000, An iterative time-stepping method for solving first-order time
dependent problems and its application to the wave equation, J. of Comp. Acoustics, 8(1),
241-255.
SERIANI, G., AND PRIOLO, E., 2000, Heterogeneous Chebyshev spectral elements for
acoustic wave modelling. In: Onate, E. et al (Eds.), ECCOMAS 2000: Finite Element
Schemes for Waves Problems. CIMNE, Barcelona (Spain), 13 pp., CD-ROM.
VALLE, S., AND CARCIONE, J. M., 2000, Detection of liquid contaminants in the subsoil
using the GPR technique, submitted to J. Appl. Geophys.
58

Seismic inversion
ROSSI, G., AND VESNAVER, A., 2000, Joint 3D traveltime inversion of P, S and converted
waves, Journal of Computational Acoustics, 8, (in stampa).
ROSSI, G., VESNAVER, A., AND PETERSEN, S., 2000, Anisotropy detection by tomography
and polarization analysis in a 3D three-component VSP, First Break, (in stampa).
BÖHM, G., GALUPPO, P., AND VESNAVER, A., 2000, 3D adaptive tomography by Delaunay
triangles and Voronoi polygons, Geophysical Prospecting, 48, 723-744.
BÖHM, G., MADRUSSANI, G., ROSSI, G., AND VESNAVER, A., 2001, Ray footprint and
redundancy in seismic tomography, Journal of Seismic Exploration, 10, (in stampa).
ROSSI, G., MADRUSSANI, G., AND VESNAVER, A., 2000, Adaptive 3D joint inversion of
direct, reflected and refracted arrivals, in: Caiti, A., Hermand, J. P., Jesus, S. M., and Porter,
M. B., Eds., Experimental Acoustic Inversion Methods for Exploration of the Shallow Water
Environment, Kluwer, Dordrecht, 235-248.
VESNAVER, A., AND BÖHM, G., 2000, Staggered or adapted grids for seismic tomography?,
The Leading Edge, 19, 944-950.
VESNAVER, A., BÖHM, G., MADRUSSANI, G., ROSSI, G., AND GRANSER, H., 2000, Depth
imaging and velocity calibration by 3D adaptive tomography, First Break, 18, 303-312.
Geophysical interpretation
BARKER, P.F., CAMERLENGHI, A., and the ODP Leg 178 Shipboard Scientific Party, in
press. Antarctic Glacial history, step 1: the continental margin drilled by ODP Leg 178. In:
J. Gamble, D. Skinner, & S. Henrys (Ed), Proceedings of the VIII° International
Symposium on Antarctic Earth Sciences, New Zealand Journal of Geology and Geophysics,
Royal Society of New Zealand.
BONACCORSI, R., BRAMBATI, A., BUSETTI, M., FANZUTTI, G.P., in press. Relationship
among X-Ray Lithofacies, Magnetic Susceptibility, P-wave Velocity and Bulk Density in
Core ANTA95-89C (Ross Sea, Antarctica): First Results. Proceedings of the Workshop
“Ricostruzioni paleo-climatiche dai sedimenti marini del MarediRoss (Antartide) e
dell’Oceano Meridionale”,Trieste, 26-27 novembre 1998. Terra Antartica.
BUSETTI, M., MARCHETTI, A., ZANOLLA, C., DE CILLIA, C. and BELYAEV, V., in press:
Seismic Structure and Stratigraphy of the South Orkney Microcontinent. In: J. Gamble, D.
Skinner, & S. Henrys (Ed), Proceedings of the VIII° International Symposium on Antarctic
Earth Sciences, New Zealand Journal of Geology and Geophysics, Royal Society of New
Zealand.
BUSETTI, M., ZANOLLA, C. and MARCHETTI, A. in press. Geological Structure of the
South Orkney Microcontinenvt. Proceedings of the workshop: “Broad Band Observations
and the Geodynamics of the Scotia Sea Region, Antarctica”, 25-26 October, 1999, Trieste
(Italy), Terra Antarctica.
CAMERLENGHI, A., REBESCO, M., DE SANTIS, L., VOLPI, V., in press. The Antarctic
Peninsula Pacific Margin: modelling flexure and decompaction with constraints from ODP
Leg 178 initial results. New Zealand Journal of Geology and Geophysics.
COREN, F., LODOLO, E., CECCONE, G. submitted. Age Constraints for the Evolution of
the Northern Powell Basin (Antarctica). Bollettino di Geofisica Teorica ed Applicata.
DE SANTIS, L., DAVEY, F., PRATO, S., and BRANCOLINI, G,. submitted. Subsidence at the
CRP drillsites from backstripping techniques. Terra Antartica, Scientific Report on CRP-3.
DI VINCENZO, G., CABURLOTTO, A., and CAMERLENGHI, A., submitted. An 40 Ar- 39 Ar
investigation of volcanic clasts in glaciogenic sediments at Sites 1097 and 1103 (ODP Leg
178, Antarctic Peninsula). In Barker, P.F., Camerlenghi A., Acton, G.A. and Ramsay, T.(Eds.)
Proc. ODP, Sci. Results, 178.
59

FERRACIOLI, F., COREN, F., BOZZO, E., FREZZOTTI, M., ZANOLLA, C., GANDOLFI, S.
AND TABACCO, I. submitted. Rifted(?) crust at the East Antarctic Craton margin: gravity
and magnetic interpretation along a traverse across the Wilkes Basin. Earth and Planetary
Sciences Letters.
HARRIS, P.T., BRANCOLINI, G., ARMAND, L., BUSETTI, M., BEAMAN, R.J., GIORGETTI,
G., PRESTI, M. and TRINCARDI, F., submitted. Continental shelf drift deposits indicate
non-steady state Antarctic bottom water production in the Holocene. Nature.
LA MACCHIA, C. and DE SANTIS, L., in press.Seismostratigraphic sequences analysis in
the Prydz Bay area (East Antarctica). In the Proceeding volume of the Italian workshop on
Antarctic Paleoclimate, Trieste Nov. 1998. Terra Antartica.
LODOLO, E. and CAMERLENGHI, A., 2000. The occurrence of BSRs on the Antarctic
Margin. In: M.D. Max (Ed.): Natural Gas Hydrate in Oceanic and Permafrost
Environments, Kluwer Ac. Pub., 199-212.
LODOLO, E., TASSONE, A., MENICHETTI, M., STERZAI, P. AND COREN, F., submitted.
Superposed tectonic styles in the Tierra del Fuego region (southernmost South America).
Terra Nova.
LODOLO, E., CAMERLENGHI, A., MADRUSSANI, G., TINIVELLA, U. AND ROSSI, G., in
press. Assessment of gas hydrate and free gas distribution on the South Shetland margin
(Antarctica), based on multichannel seismic reflection data. Geophys. Journ. Intl.
LUCCHI, R.G., REBESCO, M., BUSETTI, M., CABURLOTTO, A., COLIZZA, E., AND
FONTOLAN, G., in press, Sedimentary Processes and Glacial Cycles on the Sediment Drifts
of the Antarctic Peninsula Pacific Margin: Preliminary Results of SEDANO-II Project, In:
J. Gamble, D. Skinner, & S. Henrys (Ed), Proceedings of the VIII° International
Symposium on Antarctic Earth Sciences, New Zealand Journal of Geology and
Geophysics, Royal Society of New Zealand.
M. BRAUN, F. RAU, F. COREN AND H. SAURER. Submitted. Delimiting glacier drainage
basins using remote sensing data of various sensor types and digital elevation models of
different accuracies. Journal of Glaciology.
PROTOPSALTI, I., IMMORDINO, F., DE SANTIS, L. FANZUTTI, G. P., in press. Sediment
grain size and quartz grain morphology from Cape Roberts 1 core sample (Ross Sea):
proxies for transport and depositional processes. In: J. Gamble, D. Skinner, & S. Henrys
(Ed), Proceedings of the VIII° International Symposium on Antarctic Earth Sciences, New
Zealand Journal of Geology and Geophysics, Royal Society of New Zealand.
REBESCO, M., COOPER, A.K., O’BRIEN, P.E., and the shipboard Scientific Party, 2000.
Southern Ocean Contourites - Preliminary Results from ODP Leg 188 in Prydz Bay,
Antarctica. Comtourite Watch, issue 3, IGCP 432 newsletter, Southhampton
Oceanography Centre, U.K.
REBESCO, M., DELLA VEDOVA, B., CERNOBORI, L., AND ALOISI, G., 2000. Acoustic
Facies of Holocene Megaturbidites in the Eastern Mediterranean. In: Shiki T., Cita M.,
Gorsline D. (Ed), Sedimentary Features of Seismities, Seismo-turbidites and Tsunamites,
Sedimentary Geology 135, 1/4 (Special Issue), 65-74.
REBESCO, M., PUDSEY, C., CANALS, M., CAMERLENGHI, A., BARKER, P., ESTRADA, F.,
GIORGETTI, A., in press, Sediment Drift and Deep-Sea Channel Systems, Antarctic
Peninsula Pacific Margin. In: Stow D.A.V., Pudsey C.J., Howe J., & Faugeres J.C. (Ed), Atlas
of Deep-Water Contourite Systems. Memoir of the Geological Society, Special publication.
SAGNOTTI, L., MACRÌ, P., CAMERLENGHI, A., AND REBESCO, M., submitted.
Environmental magnetism of Antarctic Pleistocene sediments and interhemispheric
correlation of climatic events. Earth Planet. Sci. Lett
SHIPBOARD SCIENTIFIC PARTY, 2000. Leg 188 Preliminary Report: Prydz Bay -
Cooperation Sea, Antarctica: glacial history and paleoceanography. ODP Preliminary
Report, 188 [online] Available from:
60

TINIVELLA, U. AND LODOLO, E., 2000. The Blake Ridge BSR transect: tomographic
velocity field and theoretical model to estimate methane hydrate and free gas quantities.
Proceedings of the Ocean Drilling Program, Scientific Results, vol. 164. College Station
(TX): 273-281.
TINIVELLA, U., CAMERLENGHI, A., AND REBESCO M., submitted. Sesimic velocity
analysis on the continental shelf transect, ODP Leg 178, Antarctic Peninsula. In Barker,
P.F., Camerlenghi A., Acton, G.A. and Ramsay, T. (Eds.) Proc. ODP, Sci. Results, 178.
VOLPI, V. CAMERLENGHI, A., MOERZ, T., CORUBOLO, P., REBESCO, M., AND
TINIVELLA, U., submitted. Physical properties and seismic stratigraphy, continental rise
sites 1095, 1096, and 1101, ODP Leg 178, Antarctic Peninsula. In Barker, P.F., Camerlenghi
A., Acton, G.A. and Ramsay, T. (Eds.) Proc. ODP, Sci. Results, 178.
61

Presentations at meetings and conventions
Seismic data processing
WARDELL N., DIVIACCO P., SINCERI R., 2000, Pre-Processing Corrections on Very High
Resolution 3D Marine Seismic Data, 62 nd Annual International Meeting EAGE, Glasgow
2000, Expanded Abstracts, P-130.
DIVIACCO P., SINCERI R., WARDELL N., 2000, Estensione 3D per tecniche di
preprocessing di dati sismici marini ad alta risoluzione, GNGTS, Rome 2000.
Wave Modeling
CARCIONE, J. M., GUREVICH, B., CAVALLINI, F., AND SERIANI. G., 2000, A generalized
Biot-Gassmann model for the acoustic properties of shaley sandstones, 62th Ann. Internat.
Mtg. Europ. Assoc. Expl. Geophys., Glasgow (UK), Expanded Abstracts, D35.
CARCIONE, J. M., ARNTSEN, B., AND CAVALLINI, F., 2000, Simulation of ultrasonic waves
in a natural sandstone, Fifth International Conference on Mathematical and Numerical
Aspects of Wave propagation, Santiago de Compostela (Spain), July 10-14
CARCIONE, J. M., AND SERIANI, G., 2000, Numerical simulation of wave propagation in
frozen porous media, Fifth International Conference on Mathematical and Numerical
Aspects of Wave propagation, Santiago de Compostela (Spain), July 10-14.
CARCIONE, J. M., CAVALLINI, F., AND MAINARDI, F., 2000, Modeling constant-Q wave
propagation with fractional derivatives, 70th Ann. Internat. Mtg., Soc. Expl.
Geophys.,Calgary (Canada), Expanded Abstracts, 2345-2348.
CARCIONE, J.M., CAVALLINI, F., MAINARDI, F., AND HANYGA, A., 2000, Time-domain
seismic modeling of constant Q-wave propagation using fractional derivatives, Workshop
Meeting on Seismic Wave in Laterally Inhomogeneous Media V, Zahradky, Czech Republic,
June 5-9.
CARCIONE, J. M., AND GANGI, A., 2000, Gas generation, overpressure and seismic
properties, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2405-2408.
CARCIONE, J. M., GANGI, A., AND H. B. HELLE, 2000, Gas generation, overpressure and
seismic properties (CD-Rom), III Conferencia Latinoamericana de Geofisica, Villahermosa,
Mexico.
CARCIONE, J. M., CAVALLINI, F., GUREVICH, B., AND SERIANI, G., 2000, A generalized
Biot-Gassmann model for the acoustic properties of frozen porous media, Workshop on
Seismic Signatures of Fluid Transport, Berlin, Germany.
CARCIONE, J. M., CAVALLINI, F., AND SERIANI, G., 2000, Biot-type three-phase modeling
of seismic wave propagation, EGS XXV General Assembly, Nice, France.
CARCIONE, J. M., AND SERIANI, G., 2000, Electromagnetic properties of fluid
contaminated soils using composite models, EGS XXV General Assembly, Nice, France.
CAVALLINI, F., BOBBIO, M., PETTENATI, F., AND SIROVICH, L., 2000, ConVor, A newgeneration
methodology for tracing objective and reproducible iso-seismals: the case of
Feb. 28, 1925 Charlevoix earthquake in Canada. In EOS, Proceedings of AGU Spring
Meeting, May 30 - June 3 2000, Washington, DC.
FOSTER, M., LODOLO, E., TASSONE, A., GELLETTI, R., CARCIONE, J. M., 2000, Seismic
structure and sedimentary setting of the souther Magallanes Basin off the Tierra del Fuego
Island, Workshop Contiental Shelf, Buenos Aires, Argentina.
HANYGA, A., AND CARCIONE, 2000, Numerical solutions of a poro-acoustic wave equation
with generalized fractional integral operators, Fifth International Conference on
Mathematical and Numerical Aspects of Wave propagation, Santiago de Compostela
(Spain), July 10-14.
HANYGA, A., AND CARCIONE, J. M., 2000, Numerical study of pulse delay effects in a poroacoustic
wave equation, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded
Abstracts, 2337-2340.
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POLETTO, F., LOVO, M., AND CARCIONE, J. M., 2000, Acoustic velocity of drilling mud
and SWD borehole guided waves, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded
Abstracts, 1763-1766.
PRIOLO, E. 2000, Numerical simulation of the reference ground motion in Fabriano
(Marche, Italy). Proc. 12th World Conf. on Earthq. Eng. (12WCEE), 30 January - 4
February, 2000, Auckland, New Zealand. 8 pp., CD-ROM.
PRIOLO, E., MICHELINI, A., AND LAURENZANO, G. 2000, Rapporti spettrali H/V di
rumore sismico ambientale nel Comune di Catania. XIX Convegno GNGTS, Roma 7-9
novembre.
PRIOLO, E. 2000, Modellazioni numeriche del moto sismico del suolo a Catania e misure
di rumore. Corso CISM-APT: “La riduzione del rischio sismico nella pianificazione del
territorio (l’input sismico, le modellazioni, i valori di amplificazione), Lucca, 15-17
novembre.
TINIVELLA, U., AND CARCIONE, J. M., 2000, Estimation of gas hydrate concentration and
free gas saturation from log and seismic data, 70th Ann. Internat. Mtg.,
Soc. Expl. Geophys., Expanded Abstracts, 1568-1571.
SERIANI, G., PRIOLO, E. 2000, Heterogeneous Chebyshev spectral elements for acoustic
wave modelling. ECCOMAS 2000 - European Cong. on Comp. Meth. in Applied Sciences &
Engng., Barcellona (Spain), 11-14 September.
SIROVICH, L., CAVALLINI, F., PETTENATI, F., AND BOBBIO, M., 2000, ConVor: Un codice
grafico per tracciare isosiste obiettive e riproducibili. In Convegno Nazionale GNGTS,
Roma, 7 - 9 novembre.
Seismic inversion
BÖHM, G., GALUPPO, P., AND VESNAVER, A., 2000, Multiresolution in 3D seismic
tomography within physical limits, Proceeding of ICTCA ’99 Conference, (in stampa).
BÖHM, G., AND VESNAVER, A., 2000, The ray footprint in the joint 3D inversion of surface
and well data: 62th Mtg. Eur. Assoc. Expl. Geophys., Extended Abstracts, Glasgow, P-160.
VESNAVER, A., AND BÖHM, G., 2000, OBC versus conventional seismic data in 3D
adaptive tomography: 70th Annual Internat. Mtg., Soc. Expl. Geophys., Expanded
Abstracts, Calgary, 2269-2272.
ROSSI, G., MADRUSSANI, G., AND VESNAVER, A., 2000, Tomographic inversion of the
water layer in the 4D analysis: 70th Annual Internat. Mtg., Soc. Expl. Geophys., Expanded
Abstracts, Calgary, 1287-1290.
TINIVELLA, U., ACCAINO, F., CAMERLENGHI, A., 2000, Gas hydrate and free gas
distribution from inversion of seismic data on the South Shetland margin (Antarctica).
Sottomesso a Geophysical Prospecting.
ACCAINO, F., BATINI, F., CORUBOLO, P., LOVO, M., PETRONIO, L., POLETTO, F., ROSSI,
G., AND VESNAVER, A., 2000, Tomografia SWD con griglie sfalsate a simmetria radiale:
Atti 19° Convegno Nazionale GNGTS, Roma.
ACCAINO, F., BÖHM, G., MADRUSSANI, G., ROSSI, G., AND VESNAVER, A., 2000, Il
problema “acqua” nella tomografia 4D: Atti 19° Convegno Nazionale GNGTS, Roma.
DAL MORO, G., ACCAINO, F., BÖHM, G., MADRUSSANI, G., ROSSI, G., AND VESNAVER,
A., 2000, Tomografia sismica 4D nel Mare del Nord: Atti 19° Convegno Nazionale GNGTS,
Roma.
DELLA MORETTA, D., MAZZOTTI, A., AND VESNAVER, A., 2000, Individuazione di
anomalie di velocità tramite tomografia a riflessione: Atti 19° Convegno Nazionale GNGTS,
Roma.
ROBEIN, E., LAFOND, C., MAZZOTTI, A., AND VESNAVER, A., 2000, Time-lapse analysis
by AVO and tomographic inversion at a producing field in the North Sea: Atti 19°
Convegno Nazionale GNGTS.
63

ROSSI, G., BÖHM, G., MADRUSSANI, G., AND VESNAVER, A., 2000, Seguendo le impronte
dei raggi …..: Atti 19° Convegno Nazionale GNGTS, Roma.
VESNAVER, A., AND BÖHM, G., 2000, Il modello iniziale nella tomografia sismica: Atti 19°
Convegno Nazionale GNGTS, Roma.
ROSSI, G., BUSETTI, M., BALLARIN, L., PIPAN M. E GRUPPO DI LAVORO MICA, 2000,
Integrazione dei metodi geochimici e geofisici per lo studio idrogeologico: esempio di
applicazione nella piana alluvionale dell’Isonzo: Riassunti dell’80 Riunione estiva della
Società Geologica Italiana, Trieste, 411-413.
ROSSI, G., ZADRO M. e EBBLIN, C., 2000. Processi geodinamici nell’Italia Nord-orientale:
osservazioni e modellazione: Riassunti dell’80 Riunione estiva della Società Geologica
Italiana, Trieste, 414-415.
Geophysical interpretation
BUSETTI, M., 2000. WEGA (Wilkes Land) Site Survey for ODP proposal 482 AGU 2000
Spring Meeting, Washington, DC 30/05-03/06/2000, Supplement to Eos, May 9, 2000,
p. S267.
BUSETTI, M, 2000. Physical Properties from cores on the continental rise. WEGA Post-
Cruise Workshop, Hobart (Tasmania, Australia), 6-11 December, 2000.
CAMERLENGHI A., REBESCO M., DE SANTIS L., VOLPI V., DE ROSSI A. (2000),
Modelling Flexure and Decompaction on the Antarctic Peninsula Pacific Margin with
Constraints from ODP Leg 178, AGU 2000 Spring Meeting, Washington, DC 30/05-
03/06/2000, Supplement to Eos, May 9, 2000, p. S267-268.
CAMERLENGHI, A., COSTA, E., POLONIA, A., COOPER, C., FABRETTI, P., MOSCONI, A.,
MURELLI, P., ROMANELLI, M., SORMANI, L., AND WARDELL, N., 2000. New insights on
the mechanisms of deformation of the Eastern Mediterranean Ridge. EAGE Conference on
Geology and Petroleum Geology of the Mediterranean and circum-Mediterranean Basins,
Malta 1-4 October 2000. Extended Abstract Book.
GRUETZNER, J., FORSBERG, C., REBESCO, M., 2000. Orbitally Controlled Sedimentation
at the East Antarctic Continental Rise: Evidence from ODP Site 1165 (Leg 188, Prydz Bay)
AGU 2000 Fall Meeting, December 15-19, 2000, San Francisco, California, Supplement to
Eos, p. OS22A-05.
LODOLO, E. AND TASSONE, A., 2000. The South America-Scotia Plate Boundary in the
Tierra del Fuego Island: A Geophysical and Geological Study. 31th International
Geological Congress, Rio de Janeiro, August 2000.
LODOLO, E. TASSONE, A. MENICHETTI, M. COREN, F. STERZAI, P., 2000. Deciphering
the morphostructure of the Tierra del Fuego region from remote-sensing and geophysical
data. European Geophysical Society, XXV General Assembly, Nice, April 2000.
MACRÌ, P., L. SAGNOTTI, A. CAMERLENGHI, M. REBESCO, F. FLORINDO, A.P.
ROBERTS, AND A. WINKLER (2000), Environmental Magnetism and Paleomagnetism of
Sediment Drifts from the Western Continental Rise of the Antarctic Peninsula, 25° EGS
Assembly (Nice, 25-29/04/00, Abstracts).
ODP LEG 188 SHIPBOARD SCIENCE PARTY (2000), Lithostratigraphy of Continental
Shelf, Trough-Mouth Fan and Sediment Drift Deposits, ODP Leg 188, Prydz Bay, East
Antarctica, AGU 2000 Spring Meeting, Washington, DC 30/05-03/06/2000, Supplement to
Eos, May 9, 2000, p. S273-274.
ODP LEG 188 SHIPBOARD SCIENCE PARTY (2000), Physical Property Changes as a Proxy
for East Antarctic Sedimentation: First Results From ODP Leg 188 (Prydz Bay), AGU 2000
Spring Meeting, Washington, DC 30/05-03/06/2000, Supplement to Eos, May 9, 2000,
p. S272.
REBESCO, M., CITA, M.B., HIEKE, W., DELLA VEDOVA, B., ALOISI, G., WERNER, F.,
CERNOBORI, L., 2000. Deep-water Megaturbidites in the Eastern Mediterranenan, . EAGE
Conference on Geology and Petroleum Geology of the Mediterranean and circum-
Mediterranean Basins, Malta 1-4 October 2000. Extended Abstract Book.
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REBESCO, M., CITA, M.B., HIEKE, W., DELLA VEDOVA, B., ALOISI, G., WERNER, F.,
CERNOBORI, L., 2000. Megatorbiditi Abissali Oloceniche Prodotte da Onda di Tsunami nel
Mare Mediterraneo Orientale, Riassunti delle comunicazioni orali e dei poster, 80°
Riunione Estiva della Società Geologica Italiana (Trieste, 6-8/9/2000), 401-402.
REBESCO, M., COOPER, A.K., O’BRIEN, P.E., AND THE SHIPBOARD SCIENTIFIC PARTY
(2000) Southern Ocean Contourites - Preliminary Results from ODP Leg 188 in Prydz Bay,
Antarctica. Contourite Watch, issue 3, IGCP 432 newsletter, Southhampton Oceanography
Centre, U.K.
COREN, F., VIDMAR, R., STERZAI, P., 2000. Utilizzo di dati SAR per applicazioni di
protezione civile nel comune di Trieste: il progetto TS-SAR – Atti della 3 Conferenza
Nazionale ASITA – Napoli – Vol 1 pp. 627 – 632
CAPRA, A., COREN, F., FREZZOTTI, M., MANCINI, F., STERZAI, P., VIDMAR, R., 2000.
Verso Il Monitoraggio Ambientale dell’Antartide A Scala Globale –Il Progetto Vectra – Atti
della 3 Conferenza Nazionale ASITA – Napoli – Vol 1 pp. 489 – 496
COREN, F., STERZAI, P. VIDMAR, R., 2000. Interferometric Analysis of David Glacier (East
Antarctica) – ERS ENVISAT Symposium 2000 – Goteborg – ESA.
65

Book reviews
VESNAVER, A., 2000, Review of the book “Numerical methods for wave equations in
geophysical fluid dynamics” by Dale R. Durran, The Leading Edge, (in stampa).
VESNAVER, A., 2000, Review of the book “Processing near-surface seismic-reflection data:
a primer” by Gregory S. Baker, The Leading Edge, (in stampa).
Educational video
OGS co-produced an educational video entitled “PERCHÉ L’ANTARTIDE”, in which the
main scientific activities in the field of earth sciences carried out in Antarctica are
described with the aid of original video material. The video was produced also by the
National Antarctic Museum (MNA), and CNR. The english version of the video has been
presented at the Italian stand at the XXXI International Geological Congress held in Rio
de Janeiro in August 2000. It is now available for sale at the Antarctic Museum
(http://www.mna/it). Copies can be obtained also at OGS (spersoglia@ogs.trieste.it).
Summary of the video:
Title of the Italian version: Perché l’Antartide
Title of the English version: Why Antarctica
Produced by: CNR-IRPI-RCS/OGS/MNA
Production: CNR-IRPI Reparto di Cinamatogrtafia Sceintifica
Directed by: Teodoro Mercuri
Science advisors: A. Camerlenghi, M. Parotto, F. Salvini, F. Talarico
Editing: E. Valente
Original Music: V. Ricca
Archive Images: MURST - PNRA, ENEA, OGS
Computer Graphics: IMMAGINE SaS - Cosenza
VHS PAL - Color - 37 Minutes
Printed in the year 2000
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Visitors
Peter F. BARKER, British Antarctic Survey and Xavier F. Molina, Cadiz University,
visiting A. Camerlenghi within the project ODP Leg 178, Antarctic Peninsula.
M.Y. MOSKALEVSKY, Institute of Geography, Russian Academy of Sciences,
Moscow, Russia, visiting F. Coren within the VECTRA Project.
Fred J. DAVEY, Inst. of Geological and Nuclear Science, Wellington, NZ, visiting
Giuliano Brancolini within the Cape Roberts Drilling Project.
Belinda BROWN, School of Earth Sciences, University of Sydney, Sydney,
AUSTRALIA, visiting Laura DeSantis within the WEGA project
Atle NYGÅRD, Department of Geology, University of Bergen, Bergen (Norway),
visiting Laura De Santis within the STRATAGEM project.
International seminars
in solid earth geophysics
Chairman: Fabio CAVALLINI
Giovanni SANTARATO (University of Ferrara, Italy)
Electrical tomography for environmental geophysics and cultural heritage: some
examples
Michele REBESCO (OGS, Trieste, Italy)
Glacial history and paleoceanography: preliminary results of the cruise “ODP Leg
188” and “WEGA” in Antarctica
Jurgen MIENERT (University of Tromso, Norway)
Storegga slide gas hydrate drilling on the mid-Norwegian margin
Jeno GAZDAG (OGS, Trieste, Italy)
The effects of regularization on 3-D pre-stack migration
Steven R. PRIDE (University of Rennes, France)
Electroseismic wave phenomena
Steven R. PRIDE (University of Rennes, France)
The theory of poroelasticity applied to exploration seismology
Giovanni P. GREGORI, IFA (CNR, Roma, Italy)
The origin of the magnetic field and of the endogenous energy of the Earth and
of celestial bodies
Gabriele PAPARO, IDAC (CNR, Roma, Italy)
Acoustic emission as a diagnostic tool in geophysics
Alfredo MAZZOTTI (University of Milan, Italy)
Principles of AVO exploration
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Fred DAVEY (Institute of Geological & Nuclear Sciences, Wellington, New
Zealand)
Geophysical Investigation of a Modern Continental Transpressional Orogen: the
Southern Alps, New Zealand
Professor Sierd CLOETINGH (Vrije Universiteit, Amsterdam, The Netherlands)
Intraplate tectonics and continental lithosphere evolution: models and constraint
Professor Sierd CLOETINGH (Vrije Universiteit, Amsterdam, The Netherlands)
Sedimentary basins and continental topography: from the Mediterranean to the
Carpathian region
Professor Sierd CLOETINGH (Vrije Universiteit, Amsterdam, The Netherlands)
Continental rifts and rifted continental margins
Dr. Maurizio BATTAGLIA (Stanford University, USA)
GPS applications in the Earth Sciences
Dr. Maurizio BATTAGLIA (Stanford University, USA)
Temporal gravity investigations at Long Valley caldera
Dr. Maxim Yu. MOSKALEWSKY (Institute of Geography, Moscow, Russia)
Ice formation zones: probably the most sensitive indicators of short-term global
changes
Dr. Maxim Yu. MOSKALEWSKY (Institute of Geography, Moscow, Russia)
Active Antarctic coastal zones as objects for remote sensing monitoring of
environmental changes
Peter F. BARKER (British Antarctic Survey, Cambridge, UK)
The Antarctic Circumpolar Current and Antarctic glaciation
Klaus HELBIG (Hannover, Germany)
Seismic anisotropy for the rest of us
Klaus HELBIG (Hannover, Germany)
Singularities of the phase velocity of anisotropic media: specific examples for
orthorhombic media.
68

About Trieste, Italy
Overwiew
Trieste is geographically at the center of Europe and is a crossroads between
the Central-European and Mediterranean cultures. Located on a strip of land
where the white Karst cliffs plunge abruptly into the sea, Trieste has been strongly
affected by its history both in terms of architecture and life style.
Evidence of the contact between different ethnic groups can be found in the local
dialect, in the family names of the inhabitants, and in the local cuisine that cannot
be found elsewhere in Italy. In its welcoming restaurants, the savory flavors of mid-
European dishes, or the simple cooking typical of the Northern Adriatic, the
healthy and colourful cuisine of the south, or delicate seafood dishes can be
experienced.
The spirit of Trieste can be found in its cafes, pubs and buffets, which are the
traditional meeting places in the life of the city. Cafes in fact are parlours where
you can rest, read national or international magazines, and meet people.
They have been the cultural and political meeting points for writers and artist,
such as Italo Svevo and James Joyce.
Museums and theaters
There are many historical buildings, the most famous is probably the romantic
Miramare castle, the residence of the luckless Maximilian of Habsburg
and Charlotte of Belgium. Moreover, Trieste is rich in prestigious museums
boasting numerous collections of great artistic value, and in theaters,
such as Giuseppe Verdi Opera theater, opened by 1801, which is one of
the centers of cultural life with its winter opera and concert season, and
the Operetta Festival during the summer.
69

Trieste and science
Trieste is also a city of science, with a prestigious University and many worldrenowned
laboratories, like the International Center for Theoretical Physics, the
International Center for Genetic Engineering and Biothechnology, the Research
Area Park with its Synchrotron, as well the School of Modern Languages for
Interpreters and Translators, and the Osservatorio Astronomico. The OGS National
Institute is located in a beautiful green
area on the Karst plateau near the Giant
Cave, visited by thousands of tourist
each year.
A bit of history
The Roman origins of Trieste are still
visible in the well preserved remains
near San Giusto Castle, which is the
symbol of the city, together with the
Romanesque Cathedral, and the
remains of the Roman Theater erected
by Quinto Petronio Modesto in the II
Century A.D.
Because of its geographical position, as
a crossroads between important trade
routes, possession of the city was contended by Venice, France and then Austria.
After realizing the commercial importance of Trieste, and as a consequence of the
decline of the Venetian Republic, the Austrian Empire proclaimed it a free port,
thereby laying the foundation of modern Trieste and making it one of the most
important ports in Europe.
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Near Trieste
One cannot miss a visit to Venice, 150 km from Trieste. The splendid beaches of
Sistiana, Grado and Lignano are 20, 50 and 100 km away, respectively. Near Grado
is the ancient Roman town of Aquileia, with a museum, well preserved open-air
ruins and the largest Byzantine mosaic floor, dated 314 A.D.
The magnificent Dolomite mountains are only 200 km away. The town of Udine,
with numerous frescoes by the 17th century painter Giambattista Tiepolo and its
International Center for mechanical Sciences, is 80 km away.
Transportation and travel to Trieste
By air: Trieste International Airport is 33 km from the city. There are direct flights
to/from Rome, Milan, Genoa, Munich. A shuttle bus is available to town. In
addition, the airport offers rental car facilities and 24-hour taxi service.
By train: Trieste is connected to the national and international networks.
The Railway Station is located at walking distance from the city center and main
hotels.
By car: Trieste is connected to the national and international motorways, and the
A4 Venice-Trieste and Trieste-Ljubliana highways.
By sea: there is a seasonal ferry service to/from Greece.
Photo by Gabriele Crozzoli - Trieste
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TRIESTE