Geophysical data acquisition - OGS

Istituto Nazionaledi Oceanografia e di Geofisica Sperimentale - OGSGEOPHYSICSOF THELITHOSPHEREDEPARTMENTDirector: Giuliano BRANCOLINI2 0 0 0A N N U A L R E P O R T3

About OGSThe 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 Universitiesand Research. Its function is research in geology, geophysics andoceanography. More specific tasks are: crustal studies; the search foroil, gas and minerals; earthquake seismology; environmentalgeophysics; hydrogeology; hydrodynamics and ecology of the seasand oceans.These activities are carried out by the three Departments ofGeophysics of the Lithosphere, Oceanography, and Seismology, whichemploy 56 researchers, 19 senior technicians and 63 technicians.Although established in 1949, the origin of OGS can be dated backto 1841, when the Osservatorio Meteorologico was founded at Trieste.The institution publishes the results of its studies, exploration, andinvestigations, and preserves for study and reference the geophysicaldata collected by the r/v OGS-Explora during the seven Antarcticcampaigns since 1988, together with the historical archives of theTrieste seismographic station.OGS is concerned with transferring the results of its researchactivities to industry, and it is open to cooperation with scientistsfrom academic and research institutions, as well as to partnershipwith industrial research centers.Istituto Nazionaledi Oceanografia e di Geofisica Sperimentale - OGSGEOPHYSICS OF THE LITHOSPHERE DEPARTMENTBorgo Grotta Gigante 42/C34010 SgonicoTrieste, ItalyTel: 0039-040 21401Fax: 0039-040 327521E-mail: gbrancolini@ogs.trieste.itWeb: http://www.ogs.trieste.it4

ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Measurements while drilling (data acquisition) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Geophysical data acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Seismic data processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Measurements while drilling (R & D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Wave 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 . . . . 28Seismic 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Geophysical interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38• Joint Italian/Australian Marine Geoscience Expedition to the George VLand 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 plateboundary 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 - BlakeRidge BSR Case History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48• Physical properties of sediment cores from the Antarctic continental margins . . . . . . . . . . 51• Backstripping modelling in the frame of the Stratigraphical Developmentof the Glaciated European Margin (STRATAGEM) - EU project . . . . . . . . . . . . . . . . . . . . . . . . . . . 52• Earth gravity field: measurements, data processing and interpretation . . . . . . . . . . . . . . . . . 53• Synthetic Aperture Radar (SAR) remote sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55Administration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Presentations at meetings and conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Book reviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Educational video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Visitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67International seminars in solid earth geophysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675

IntroductionThe Department Geophysics of the Lithosphere (GdL) carries out studies andresearches in a wide range of applied and theoretical geophysics. It is organisedinto four research groups, three operative groups and one support group. Itemployees 20 researchers, 16 senior technician and 27 technician. During 2000the Department gave hospitality to 7 grants.Main activity of the GdL is the application of geophysical methods to theknowledge of the underground. This knowledge has always been important inhuman history, for finding out minerals and fresh water, but only in the last 50years the need for accurate reconstructions of the underground geology drasticallyincreased, due to the world wide utilisation of the hydrocarbon as a primary energysource.Only in the last years however, grew the consciousness that the underground is amasterpiece in the global environment and that its knowledge is of importance notonly for the exploitation of natural resources, but also for a sustainablemanagement of the global environment.GdL activities during the 2000 were based on a deep consciousness of the centralrole that the correct and sustainable managment of the underground resourcesplays on the human development and impaction on the natural systems. The mainfields of our researches can be grouped in four main fields:1) to recognise the presence of natural resources, with particular attention tohydrocarbon,2) to reconstruct the dynamic of the natural systems through the study of thesediments,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 multichannelseismic data acquisition and processing for oil industry.In the hydrocarbon detection, a major improvement was reached by the first truly3D Seisbit survey during the drilling of the Vallazza well. The Seisbit techniques isa trade mark OGS-Agip and it allows the reconstruction of a direct and reverseVertical Seismic Profile during the drilling by listening to the noise produced bythe drilling bit. The 3D multi-offset in the Vallazza well produced, in a-quasi-realtime, an accurate and clear reconstruction of the geological strata below thedrilling bit.The 2000 budget for natural resources’ study was 795,000 EURO, which derivesfrom research contracts with Agip and European CommunityThe study of the natural systems through the sediments was focussed in the highlatitude environments (Artic and Antartic). High resolution seismic, correlated tosediment cores and drilling data, were used for detailed reconstruction of the lastglacial-interglacial cycles and to infer type and characteristics and dynamics of theice caps. Study have been carried out on two marine cruises, one in the Weddel1

Sea, close to the Antarctic Peninsula, in co-operation with the US AntarcticProgram, the other off the Wilkes Land, in co-operation with the AustralianAntarctic Program.The 200 budget for these studies was 450,000 EURO, mainly supported by theItalian Antarctic Program.The main problem we are facing in the application of the traditional onshoreseismic to environmental and hydrogeological studies, is the need to drasticallyincrease the resolution of the method: our approach follows three convergentdirections: i) by a theoretical approach based on the study and modelling of thepropagation of P and S waves in heterogenous-visco-elastic media; ii) studying thesource, 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 supportedby the Ministry for University and Research and by Fondo Trieste.During the 2000, the GdL was also involved in significant activities for the oilindustry, particularly Agip. These were based on the Seisbit tecnology that wasapplied for monitoring the bit position and carring direct and reverse WSP whiledrilling.The total budget for these activities was 1,230,000 EURO.Giuliano BRANCOLINIDepartment Director2

PRESIDENCYIGINIO MARSONADMINISTRATIONANDSERVICESIDEPARTMENTOFGEOPHYSICSDEPARTMENTOFOCEANOGRAPHYDEPARTMENTOFSEISMOLOGYGIULIANO BRANCOLINIRENZO MOSETTIALBERTO MICHELINIADMINISTRATIONOFFICEDARIO COLONNELLOWAVEMODELLINGGÉZA SERIANIGEOPHYSICALDATA ACQUISITIONDANIEL NIETO YABARSEISMICINVERSIONALDO VESNAVERMEASUREMENTSWHILE DRILLING(DATA ACQUISITION)GIULIANO DORDOLOMEASUREMENTSWHILE DRILLING(R & D)FLAVIO POLETTOSIGNALPROCESSINGNIGEL WARDELLGEOPHYSICALINTERPRETATIONANGELO CAMERLENGHI3

Measurements while drilling (data acquisition)Coordinator: Giuliano DORDOLOG. CAPELLIB. CATTANIP. COMELLIG. CRISTOFANOP. GHIDINIM. GIORGIB. MOIMASV. PASCIULLOA. SCHLEIFERG. VASCOTTOF. ZGAUCIn the year 2000 the ASTI group, keeping on the industrial application of theSeisbit ® System 1, begins the field tests and research applications of the newversion of Seisbit ® System 2.Starting the application of the new system means a complete revision and ahardware and software redesign of the older version. It was necessary indeed toincrease the operational capabilities like interfacing with other systems. Most ofthe hardware problems due to the synchronization between different systems hasbeen solved developing new hardware specifically for our purpose. Using these newproducts with completely new software solutions, the new system is able tomanage the timing problems merging acquisition data form different systems withdifferent sample rates and different sampling characteristics.Redesigning the system makes also possible to manage a huge amount of differenttypes of acquisition units such as Sercel SN348, SN368 and SN368E mixed almostwithout limits.The analogic section of the system has been modified and improved too, so in thedata 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 thetargets:Cerro F.- service well: seismic while drilling acquisition with ENI-AGIP. 55 channelseismic 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. 60channel seismic survey. Main target top of carbonate platform, deviation geometrycontrol, refraction survey for static corrections, indications on well casingoperations, receivers pattern test.Cerro F.- research well: seismic while drilling acquisition with ENI-AGIP in theframe of a research project. Down-hole instrumentation testing.Geothermic service well: seismic while drilling acquisition service in Larderelloarea for ENEL. Well geometry tracing. 164 channel pseudo-3D seismic survey.Geothermic wellrecording plan.Rig: 12 pilot channelsL1 :22 channels, L2: 26 channels, L3: 26 channelsL4: 26 channels, L5: 26 channels, L6: 26 channelsFirst channel offset from centre of well: 325 m,distance between two station units: 75 m.6

Vallazza research well: 3D-RVSP seismic survey. – CEE Research Project. ThisProject required a large amount of technical and human resource, to realize anexperimental survey, with a 500 station units spread configuration. The main goalwas the validation of the 3D Seismic While Drilling. The spread configuration issurely unusual: it consists in 2 circles centred on the well and 2 branches crossedon the well too. The units pattern follow a saw-teeth shape, each segmentorthogonal to the radius of the circles, of 1000 and 2000 m length respectively. Theoperation scheduling, people, instrumentation, acquisitions and data managementfollowed the expected flow without problems. There was some difficulty solving thedata management problems, due to the huge amount of them: over 130 Gbyte.3D-RVSP recordingpattern.7

After these research and testing phases, the new acquisition and pre-processingtechniques are validated and have been applied in the service and industrialsurveys.Cerro Fal. Service well: 54 channels seismic survey, main target top oil trap,refraction survey for static corrections, using stationary noise too, indications onwell casing operations.Before data acquisition, it has to perform some preparatory activities, such asscouting, topography units location, positioning of the recording materials,mounting of the sensor pilots on the rig and the short refraction survey to havethe static corrections.Elaboration and application of an accurate static correction is a very importantstep in the processing of VSP and VSP CDP mapping. Data correctly elaborated areuseful in drilling too, i.e. to schedule the casing operations.Example of a while drilling seismicsurvey 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 thealready existing informations (seismic lines, up-hole survey, stacking chart,dromochrones and thematic maps) and then the foreseen stratigraphy. After theray-tracing, this set of elements allowed to plan the data recording geometries,fitting the basis extension with high channel number (48), using the Summittelemetric system and a Hydrapulse as source.Moreover, together with this new approach using short refraction for a whiledrilling survey, data are dynamically correct with Seisbit ® information until thedatum plane depth.The ASTI group worked in collaboration with more crews up to 24 people, most ofthem OGS senior technicians and engineers and some people from the contractorscompanies.After the testing phases of the Seisbit ® 2, innovation studying and designing arepursued, to improve the automation capabilities and the data storage andelaboration features in field.SHORT REFRACTION SURVEY RECORDING PLANSpread configurationSEISBITchannelSEISBITchannelSEISBITchannelSEISBITchannelSEISBITchannelSEISBITchannelP.s.: shot pointG1 - G48: geophones of the seismic short refraction profileShort refraction spread example.9

Geophysical data acquisitionCoordinator: Daniel NIETO YABARS. BARBAGALLOL. BARADELLOR. BOLISA. BRATUSG. COVAC. D’AMICANTONIOE. DEL NEGROF. FANZUTTIM. GROSSIB. MARINOP. PAGANINIM. POROPATG. VISNOVICThe wide and profitable group activities, supporting the other research groups, arelisted below. Acquiring appliances have been implemented in all the operatingfields, such as GPR, geoelectric, onshore and offshore seismic investigations.A methodological research project has been presented and approved at the FondoTrieste, with the results of a further technological development of the acquisitionsystems and an improvement of scientific technicians.Acquiring appliances are:SEISMIC ON-SHORE:Positioning• Total Station SOKKIA• DGPS• Infrared level LEIKA 3003Energization• MiniBang ISOTTA• Seismic Sources Power Weight Drop PWD-80• IDROBANG for well energization• Vibroseis-MINIVIB (to be completed)• HammerGeophones• Single 100 Hz• Array of 6x20 Hz• Array of 12x10 HzRecording• SUMMIT telemetric 140 channels• OYO DAS-1 96 channelsSEISMIC OFFSHORE:Positioning• DGPS• Communication Technology Navigation SystemEnergization• 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 compressor10

• Standard 20’ container modified to host the compressor, the high-pressure aircontrol and the airgun workshop, complete with all the required electricwiring.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 winchRecording• OYO DAS-1 recording system, expanded to 96 channels, with three IMB3480/3490 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 nodesGPR (Ground Penetrating Radar)• SIR-2000 GSSI• Antennas:• SUBECHO 35 MHz- SUBECHO 70 MHz- GSSI 100 MHz bistatic- GSSI 200 MHzMAGNETOMETRIC ACQUISITION:• Cesium Gradiometer G-858, Geometrics• Proton Magnetometer G-856, GeometricsThe group’s activities are:• Project Tasman Sea. Geophysics research project in the Tasman Sea, with theR/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 ofthe Mica Project has been acquired using the new Summit telemetricacquisition system and comprehends the sites of S. Pier d’Isonzo and Iamiano11

(GO). The energizing systems were an Isotta gun and PWD. In the Mica project127 transepts of 20-channels have been acquired, for a total amount of 994points, while in Iamiano the acquirement grid was provided by 600 channelsand 530 energization points.• Integrated metodology in the Mica project. Combined to the high resolutionseismic, the two sites of S. Pier d’Isonzo and Iamiano were characterised usingGPR, ERT (earth resistivity tomography) and magnetometry. The 2Dresistivity profiles had length from 31 to 315 m.• TRUCK Project. In February 2000, for the AGIRE srl society a magnetic surveywas carried out on an area near PERPIGNAN (F). The aim of the survey wasthe determination of magnetic anomalies connected with the supposedpresence of a buried vehicle. The area was delimited with a total stationSOKIA. The vertexes of the area were joined with the local topography. Thehigh-resolution magnetic acquisition was carried out with a portable cesiumgradiometer GEOMETRICS mod. G-858 along parallel profiles with a 2-mrange. Magnetic data were reduced by the field reference model IGRF 2000.• KRSKO High Resolution. In February 2000 three high-resolution seismicprofiles, with a total length of 4 km were recorded in the surroundings of theKRSKO nuclear-power plant (SLO). This acquisition was performed in theframework 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 thehistory and collecting sedimentological, biostratigraphical, biological andoceanographical information on the environmental change of the sea floor inthe area that, until five years ago was still covered by the Larsen ice platform(Eastern part of the Anctartic peninsula). Among the various applied surveysthe group took part in data acquisition with multibeam echosounder, SideScan Sonar and monochannel reflection seismic. The expedition has beencarried out in May 2000, on the icebreaker N.B. Palmer (USA).• Extended Program Geophysical Research in the surroundings of the KrskoNPP. Three new seismic lines were made with a double purpose: to clarify theposition of some faults zones and correlate the seismic data with logs of thedrill hole Drnovo 1.• Project STRATAGEM. Research project with the R/V research ship Dana, inthree different investigation areas. In one of these, the Faeroe-Shetlandmargin, the main aim was the construction of a mid –to late Cenozoicstratigraphic framework for the Faeroe-Shetland and the setting up anevolution model for the Faeroe-Shetland margin, with particular emphasis onthe development of shelf-margin progradational wedges. During the fieldwork4 monochannel high-resolution reflection profiles have been recorded, for atotal 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 arrayof 10 Hydrophones 1.6 m space and one recording system Elics Delph-2x. Thepositioning was supplied by SHIPMATE GPS equipped with differential GPScorrector.12

• Offshore gravimetric survey “CERVETERI”. The gravimetric offshore programin the area covered by the IGM 1:50000 “CERVETERI” sheet was executed forthe “Servizio Geologico Nazionale” with a floor gravimeter Lacoste &Romberg on the ship N/R VEGA owned by Sopromar. 300 points, with a 1-kminterval between them, have been measured.• Integrated methodologies at the Doria Cave. This test was carried on to definethe applicability of the ERT, GPR and magnetometry in detecting undergroundcaves in Karst area.• High-resolution mono-channel seismic Acque Profonde. The investigated areacomprehended sea/littoral, lagoon and continental/fluvial multipleenvironments in the Marano Lagoon. The survey was carried out by theemployment of two high-resolution acquisition systems linked to a satellitepositioning system. The first was composed by a Delph monochannelacquiring system synchronized with a Uniboom high frequencyelectrodynamical impulse source. The second by an integrated acquiringenergizingChirp-datasonic system using a non-impulsive high frequencysource, allowing centimetric resolutions.• High Resolution Survey in the Barcis Lake. Research project for the “RegioneFriuli Venezia Giulia” with monochannel seismic. A Uniboom energizingsource, a Delph acquiring system and a DGPS positioning system weremounted on a boat provided by the Barcis municipality.During this year Salvatore Barbagallo and Giorgio Cova have retired: we wouldlike to thank them for their work.High resolutionseismic in Mica. 3Ddata acquisition inthe Iamiano site.13

High-resolution mono-channelseismic 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 ProgramGeophysical Researchin the surroundings ofthe Krsko NPP.Acquisition near thenuclear power plant.15

Extended ProgramGeophysical Researchin the surroundingsof the Krsko NPP.Seismic line.Integratedmethodologies at theDoria Cave. GPR(Ground PenetratingRadar) section.TRUCK project. High resolutiongradiometric acquisition.Mono-channelseismic offshore.Data acquisition.16

Seismic data processingCoordinator: Nigel WARDELLG. CENTONZEL. CERNOBORIP. DIVIACCOM. MARCHIR. OLIVOTTIC. PELOSM. ROMANELLIR. SINCERIL. SORMANIF. ZGURDuring 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 both2-D and 3-D. However, the year was marred by the tragic loss of Licio Cernoboriwho died suddenly after a short and terrible illness. His experience, self-motivationand enthusiasm had made him a key member of the group. He will be greatlymissed, as a colleague and also as a friend.One of the projects in which Licio was very much involved, was “Geophysicalresearch in the surroundings of the Krsko Nuclear Power plant”, to study thegeological stability of the area around the nuclear power plant at Krsko inSlovenia. The three high resolution lines that had had to be postponed, in 1999,due to inclement weather conditions, were acquired in the spring. Although fieldtests had been conducted on the first line, during the winter, further testing wasperformed to take into consideration the different weather conditions for the threeremaining lines. The group utilised the Vista processing package installed on alaptop computer to analyse these field tests. The data were subsequently finalisedin the processing centre in Trieste. An elaborate processing sequence was used toattempt to overcome problems introduced by ploughed fields and shallow peatlayers. These near surface conditions caused static problems and absorption of thehigh frequency component of the frequency spectrum.To complete the interpretation of the area and to better define the geologicalstructures, three additional lines were planned in the vicinity of the power plant.These lines were semi-regional in character; the acquisition parameters were midwaybetween those of the regional and the high resolution lines. Since the Isottarifle, which was used for the high resolution, was not considered to have thepenetration necessary for the target structures, a new source Hydrapulse, apowered weight drop, was used for these lines. This choice entailed more testingin the field to optimise the recording parameters for the new source and objectives.The processing group provided the technical expertise during these tests. This wasfollowed by quality control (QC) and processing in the field to produce preliminarystacks. Since these surveys were very close to the nuclear power plant, 50 Hz noisefrom the power cables emanating from the power station, was very evident on thefield records. The QC and processing in the field was important to monitor that thelevel of this noise was not saturating the signal and that it could be attenuated inthe processing phase.The final processing of these data, which was performed at the processing centrein Trieste, was tailored to detail the particular objectives and to match the regionallines recorded the previous year. To assist the interpretation, the final stacksections of both datasets were migrated and converted to depth. All the processing17

sections were included, in digital form on a CD-ROM, with the interpreted resultsand conclusions in the final report.Another important project in which the group was involved was the CROP or DeepCrustal project. During the year, the processing of first part the seismic line CROP-11 (From Lazio to Abruzzo) was finalised. A non-standard processing sequenceinvolving noise reduction, coherency enhancement, array simulation andrefraction statics had been derived to improve continuity and enhance the signalto noise ratio, especially at deeper depths. This sequence is also being applied tothe second part of this line (from Abruzzo to the Adriatic Coast) which theprocessing 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 environmentin the WEGA project, offshore Wilkes Land in Antarctica. As part of this project tostudy the glacial history, analysts from the processing group participated in thiscruise. In the spring of 2000, 1500 kms of multi-channel seismic were acquired byan Australian research vessel. Following initial processing on board, the data weretransported back to Trieste for further processing and finalisation. The final datawere presented at an International Conference in Tasmania in December.The research activities of the group continued with the EU project Very highresolution marine 3D seismic method for detailed site investigation (VHR3D)which is aimed at a cost-effective detailed 3-D reconnaissance of the seabedsediment properties for geological, geotechnical and environmental siteinvestigation purposes. The group plays a major role in this three-year projectcoordinating OGS’s contributions in processing, tomography, geotechnicalstudies, and seismic modelling. In this third year of the project, limitations in theacquisition technology, restricting the available navigation information and therange of offsets, reduced the involvement of the other OGS contributors. However,additional research had to be undertaken by the processing group to include preprocessingcorrections in 3-D for wave-motion and tidal effects.Initial work had already been completed by the group, defining a methodology in2-D that used static corrections to correct for wave motion. This had beenextended in the second year to include geometry regularisation to take intoaccount variations in cable positions, and hence offset, which were not able to berecorded by the navigation system. This methodology was presented at the EAGEmeeting in Glasgow in June 2000. The 3-D corrections were based on a similarstatistical analysis of the first break arrivals after common offset spatial averagingthat had been used in 2-D. In the 3-D case, the spatial averaging had to beperformed in an areal sense to include not only the component of the wave motionbut also the component due to tidal differences between lines. First results on adataset recorded in the Dover strait were encouraging.Members of the group participated in the next VHR3D cruise in St. Austell Bay inCornwall where the two different multi-cable acquisition systems, proposed in theproject, were used. After seeing these acquisition systems in operation a numberof modifications were made to improve the technique. Since the cables were seento act independently at times, a separate component was derived for each cablerather than for each shot. Also, different 3-D spatial filters had to be introduced to18

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 boththe acquisition systems. The complex channeling in the area was well delineatedwith a vertical resolution of less than half a metre. A presentation on this 3Dmethodology has been accepted for the 63rd Annual Meeting of the EAGE inAmsterdam 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 ofconvergence and sedimentation in the Eastern Mediterranean. Within the project,1000 kms of seismic data, recorded by OGS in the seventies, was reprocessed andinterpreted in order to design scaled physical models for sediment deformationexperiments in the laboratory. This physical modelling was performed by a teamfrom the University of Parma (Department of Earth Sciences) and IGN-CNRBologna. The reprocessed data crossed the eastern Mediterranean ridgeaccretionary complex and extended to the Herodotus foredeep and African foreland(Nile river deep sea fan). The reprocessing involved re-generation of stack sectionsfrom the original tapes, migration and depth conversion. Pre-stack depthmigration was also performed on selected parts of the profiles with Geodepth ©software. The migration velocity focusing analysis and grid tomography inGeodepth © was also used to study the velocity distribution and define possiblefacies changes in the salt sequence.The development of the group’s capabilities in 3-D processing continued with theMICA project. The aim of this project, funded by the ‘Fondo di Trieste’, was todefine the flow of underground water in the zone of the Carso. Two high resolutionland 3-D surveys were planned in the project; one was acquired in the early part ofthe year, whilst the second towards the end of the year. The processing group wasinvolved 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 interestafter 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 routingfor rail and road tunnels under mountainous regions. These data tend to beinherently noisy and lacking in continuous reflections due to the deformed, oftenmetamorphic, areas in which they are recorded. Careful noise reduction andcontinuity enhancement routines have been used in the final sections. Continuedclose ties with other academic institutions produced a number of small processingprojects. 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 bean important part of the group’s activities. All the Mediterranean data recorded byOGS in the seventies, and about 70% of the data recorded by OGS in the Antarcticin recent years, have been transcribed from their original field format to SEG-Y on19

3480/90 cartridges. The group also performed a transcription service forENEL/ERGA, copying their entire seismic field data library onto cartridges andCD-ROM.Processed stack data from the Antarctic is also being transcribed onto CD-ROM aspart of the Seismic Data Library System (SDLS) project. The Antarctic SeismicData Library System (SDLS) provides open access to multi-channel seismicreflection data collected by all countries in the Antarctica, to facilitate large-scalecooperative research projects. The SDLS has 11 library branches that are locatedin 10 countries world-wide. Researchers may go to any library branch to inspectAntarctic multi-channel seismic reflection data. The processing group performsany necessary reformatting, filtering and scaling to the stack data beforetranscribing them, in SEG-Y format, onto CD-ROM together with a visualisationprogram.VHR3D - Common offset surfaces (Dover)Results of the 3Dmethodology fordetermining staticcorrections for tide andwave motion effects.A common offsetsurface of the waterbottom is shownwithoutcorrections (top),with tidal corrections(middle) and with tidaland shot corrections(bottom).20

Results of applicationof the staticcorrections to astacked 3D datacube. The originaldata is on the leftand the staticcorrected cube onthe right.VHR3D - Dover 3D cubeSt. Austell Bay 3D CubeTime slice at 33 ms.Time slices from theprocessed3D cube fromSt. Austell Bayafter application of thestatic corrections fortide and wave motion.The high resolutiondefinition of thechannels is clearlyevident.WAVE MODELINGSt. Austell Bay 3D CubeTime slice at 35 ms.21

SMS-53 SP 1175-1475 Velocity Analysis “semblance”NAn example of the migration velocity focusing analysisusing the GeoDepth Pre-stack depth imaging package.A line extractedfrom the Micaproject 3D cubeshowing theimprovementobtained by theapplication of 3Dresidual statics(bottom) over theoriginal stackdata (top).22

Measurements while drilling (R & D)Coordinator: Flavio POLETTOC. BELLEZZAP. CORUBOLOA. CRAGLIETTOM. LOVOM. MALUSAL. PETRONIOG. PINNAU. TINIVELLAS. TINONINThe research was primarily aimed at studying in deep and extending the applicabilityof the seismic while drilling technology as well as increasing the industrialpotential by raising the number of geological information given by the method.The projects developed by the SERE group in collaboration with ENI/AGIP are thefollowing:A) Acquisition of a 3D reverse VSP using the drill-bit source during the drilling ofan ENI/AGIP well in Sicily (Italy).Such a method, which is the only capable of acquiring an onshore 3D VSP ona large number of acquisition levels, was applied in cooperation with the “whiledrilling” data acquisition group (ASTI).The experiment, funded with the contribution of the 3D-RVSP European Unionprogramme (Contract Thermie OG 278/98 IT/UK, partners OGS, ENI/AGIP andProsol Technology), allowed us to acquire a good quality 3D Seisbit dataset.The receivers were placed on a 15 square Km area and the investigation wascarried out on a 3 km long well section.We used radial and circular seismic lines in a geometry suited to discriminatethe signal and noise arrivals (first Figure). During the survey setup wecomputed some 3D elastic models and after the acquisition phase data havebeen processed as multioffset vsp sections along the cross shaped radial seismiclines. We are still processing the circular lines with the aim of obtainig a 3Dreverse vsp imaging.B) Theoretical analysis and experimental study of signals measured in the drillpipes and of reflection coefficients at the drill-bit / rock interface. This allowedus to measure the acoustic impedance of the drilled formations and to gatherinformation about the signal amplitude in relation to changes in the drillstringand drilled rock (formation evaluation while drilling).C) Feasibility study for the Geosteering project (ENI/AGIP). This project is aimedat steering the drilling operations basing on “while drilling” information.Particularly, the research is aimed at the tuning of a method and an acousticsystem to be used downhole for monitoring the lithology in the vicinity of thedrill bit for the purposes of drillers and geopysicysts.The feasibility study includes the use of downhole instruments and thesyncronization with surface measurements. Field and laboratory tests havebeen carried out with the prototype instrument called Instrumented SubENI/AGIP. Such measurements allowed us to detect the drill bit signal also inhighly unfavorable conditions, even for the surface measurements (secondFigure). Numerical modelling methods were developed to analyze the signalspropagation throughout the drill string. Moreover, the research was extended23

to study methods suited to predict overpressure zones using SWD and to theanalysis of electromagnetic signals in a well.D) Feasibility study and preparation of the technology for the extension of themethod to the deep sea and downhole environments, in collaboration withENI/AGIP and Tecnomare.E) In deep study and analysis of datasets collected during a SWD experimentcarried out in a tunnel. Study of the applicative contexts, of the tunnel boringmachine signal resolution and of the signal and noise components.F) Study and multioffset processing of a dataset acquired in a geothermal areaalong seismic lines laid out in a multiradial geometry with respect to the wellhead (in collaboration with ENEL). Analysis and preparation of a dataset fortomographic inversion, in collaboration with REDS.24

Wave modelingCoordinator: Géza SERIANISeismic modeling for exploration geophysicsJ.M. CARCIONEF. CAVALLINIG. SERIANIThe numerical modeling of seismic waves plays a key role in explorationgeophysics, reservoir engineering, and environmental studies. In the year 2000,OGS has continued this kind of activity under the aegis of the EuropeanCommunity (research program “Detection of Overpressure Zones from Seismicand Well Data - ODS”), with emphasis on the following topics.The first one is the estimation of gas-hydrate concentration and free-gassaturation. When no direct measurements are available, a detailed knowledge ofthe compressional and shear velocity is essential for the quantitative estimation ofgas hydrate and free gas in bottom-simulating reflectors (BSR). Discrepanciesbetween experimental velocity profiles and the velocity for water-filled sedimentsreveal the presence of gas hydrate (positive anomaly) or free gas (negativeanomaly). A three-phase Biot-type theory yields wave velocities of sedimentssaturated with water and gas hydrate, while the Hill average is used to model thepatchy free-gas saturation below the BSR. The model has been applied to field dataacquired by the r/v OGS Explora in Antarctica.Velocity field across a section parallelto the South-Shetland Margin in Antarctica.The BSR is evident at the left wherea low-velocity layer, caused by the presenceof free gas, is embedded in a highervelocity background.A line extractedfrom the Micaproject 3D cubeshowing theimprovementobtained by theapplication of 3Dresidual statics(bottom) over theoriginal stackdata (top).Concentration map of gas hydrate(positive values) and free gas (negative values)corresponding to the BSR offshore theSouth-Shetland Islands. The figure showsthe hydrate concentration (and free gassaturation) multiplied by the porosity(i.e., the volume concentration). In this way,we can compare the content of hydrate andfree gas between zones of different porosity.25

Poisson’s ratio as an indicator of overpressure has been investigated. Poisson’sratio values of dry samples are significantly smaller than those of fluid-saturatedsamples. The values are anomalously high for high pore pressure, with thepossibility of differentiating between gas-saturated, brine-saturated and oilsaturatedporous rocks. Two overpressure models, based on oil/gas conversion anddisequilibrium compaction, have been developed to obtain Poisson’s ratio versusdifferential pressure. Poisson’s ratio is approximately constant at high differentialpressures and increases (decreases) for saturated (dry) rocks at low differentialpressures. Fluid type can be determined at all differential pressures from Poisson’sratio. Moreover, the analysis is extended to the transversely isotropic case bycomputing the three Poisson’s ratios. Experiments performed on cores, underdifferent pressure conditions, and calibration of the models with these data,provide a tool for inverting pore pressure from seismic data.10.20.150.1gaswateroil(a)20.30.250.20.150.1gaswateroil(b)30.250.20.150.1gaswateroil(c)0.050 20 40 60 80 100Effective pressure (MPa)0.050 20 40 60 80 100Effective pressure (MPa)0.050 20 40 60 80 100Effective pressure (MPa)Anisotropic Poisson’s ratioes σ 1(a), σ 2(b) and σ 3(c), for brine-, oil- and gas-saturated Bereasandstone 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 1BNWSEformationsvel. P (km/s)Snapshot of theseismic wave fieldpropagating in acomplex geologicalstructure during a 3Dsimulation of aseismic-while drillingexperiment.depth (km)distance (km)26

Phase velocitiesof the five wavemodespropagating inpartially frozenBerea sandstoneversus waterproportion.Phase velocity (km/s)543210P1S1P2S2P3(a)0.05 0.1 0.15 0.2Water proportionSnapshot of the rock-framevertical particle velocitycorresponding to the wavemodes illustratedin the previous figure.The compressional wavesare labeled P1, P2 and P3,and the shear wavesare labeled S1 and S2.Finally investigation on dynamics of frozen porous media has been conducted. Theknowledge of the physical properties of frozen soils is essential, in polar areas, forthe exploitation of mineral resources and for the construction of highways andpipelines. A three-phase Biot-type theory has been developed to describe a seismicwave propagating in a porous rock filled with ice and water. The model predictsthree compressional waves and two shear waves, and takes into account energydissipation and wave dispersion as observed in rocks. Attenuation is introducedwith exponential relaxation functions, which allow a differential fomulation basedon memory variables. The wavefield is computed with a grid method based on theFourier differential operator in space and a Runge-Kutta time-integrationalgorithm. The presence of slow quasi static modes makes the differentialequations stiff and hence numerically untractable as such. But a splitting timeintegrationalgorithm has allowed to solve the stiff part analytically. The algorithmis second-order accurate with respect to time and has spectral accuracy in thecomputation of the spatial derivatives.27

Ground penetrating radar for environmental problemsJ.M. CARCIONEF. CAVALLINIG. PADOANG. SERIANIThe ground-penetrating radar (GPR) has unique capabilities as a subsurfaceexploration device; as such, its applications (since 1992) include archaeology,mining, glaciology, hydrogeology, and environmental remediation. But itsperformance is highly sensitive on the knowledge of the physics of the medium andof the instrument itself. Therefore, basic research in this field is of crucialimportance for pracical applications as well. Many concepts and techniques thatwere devised for seismic waves can be applied to the processing of GPR data, invirtue of the mathematical analogy between electromagnetic and elastodynamicequations. This research, funded by the Regional Government of Friuli - VeneziaGiulia (northeastern Italy), aims at exploiting these methods for the monitoring ofa polluted area.The exploding-reflector method, originally developed for seismic waves, has beenadapted to produce zero-offset synthetic radargrams without need to computecommon-shot records. The basic underlying idea consists in assuming that eachreflecting point acts at the initial time as an instantaneous source of motion witha magnitude proportional to the normal-incidence reflection coefficient. Themagnetic permeability is used as a free parameter to obtain a constant-impedancemodel and, so, to avoid multiple reflections. Moreover, the condition that the phasevelocity remain unchanged also requires the scaling of the permittivity and of theconductivity. Thus, the method generates normal-incidence reflections, i.e., thosehaving identical downgoing and upgoing wave paths. In an example withtransverse-magnetic equations, this method has shown more accuracy, but lessefficiency, than the plane-wave technique.Analytical solution for lossy anisotropic media has been developed. Microstructuralfeatures, fine layering, and fluid-filled cracks give rise to electric and magneticanisotropy, while mineralized water in the fractures makes conductivityanisotropic. Water relaxation and ferromagnetism are responsible of energydissipation. This motivates an orthotropic constitutive law in which attenuationstems from the Debye model. The corresponding solution is obtained in thefrequency domain from a change of coordinates that turns Maxwell’s equationsinto Helmholtz equations, which are solved analytically. Then, the solution in timedomain is recovered by numerically computing the inverse Fourier transform. Theresults are in agreement with a plane-wave analysis of the slowness, theattenuation and the energy velocity.Simulation of the ground motion caused by earthquakesand site response analysisE. PRIOLOG. LAURENZANOSynthetic seismograms computed as a solution of the full-wave propagationthrough a realistic geological structure can reproduce accurately much of theeffects of medium heterogeneity and local soil conditions on the ground motioncaused by earthquakes. They are a powerful tool for building seismic hazardscenarios 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 method28

(SPEM) and the Wavenumber Integration Method (WIM), which have verydifferent features.The 2-D Chebyshev spectral element method (SPEM) is a high-order finite elementtechnique, which solves the variational formulation of the equation. It has beenentirely 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 highorderChebyshev polynomials, make the SPEM particularly suitable to solvenumerically the seismic wave propagation through complex geological structures.The WIM solves the 3-D elastic full-wave equation in a plane layer medium. It hasbeen developed by R. Herrmann at St. Louis University. Synthetic seismogramscontain 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 tobe defined. These properties make WIM suitable for performing predictions at a regionalscale, as well as for kinematic modelling of the rupture process along the fault.The methodological development has been focused on improving the capability ofthe SPEM for building complex models. In the standard implementation, thespectral element method decomposes the whole model into a patch of sub-regionshaving constant physical properties. This approach is inadequate to represent geomodels,since they usually feature small scale heterogeneities and mediumproperties that change continuously in the space. This fact motivated thedevelopment of a different approach, in which 1) the geological structure is builtupthrough an interpolator which handles discontinuities, and using a minimumnumber of control points and lines, and 2) the mesh size adapts continuously tothe medium properties and is controlled by few geometric constraints.In general, the activity has been developed mainly within a number of nationalresearch projects funded or co-ordinated by the GNDT1 and GNV2. During year2000, one three-years project – the Catania Project – finished its activity, while fivenew 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 ofSeismic Hazard in Seismogenic Areas: Application to the Central and SouthernApennines; 2) Damage Scenarios in the Veneto-Friuli Area; 3) Detailed Scenariosand Actions for Seismic Prevention of Damage in the Urban Area of Catania; and4) Integrated Seismic Methods Applied to the Investigation of the Active VolcanoStructure. An Application to the Phlegrean Fields Caldera. We will shortly presentsome of those projects in the following.The Catania Project aimed at evaluating the seismic risk of a highly urbanised areatypical of the Mediterranean region. The OGS contribution of the last year wastwofold. In a first part, we simulated a recent event, the M 5.8 earthquake, whichstruck Eastern Sicily on December 13, 1990, and was recorded by the CataniaENEA-ENEL accelerometric station. Seismograms computed using the SPEMagree very well with those recorded by the accelerometric station. On the contrary,any plane layer representation, which simplifies the complex structure used bySPEM, does not provide a comparable agreement. In this case, the syntheticseismograms are computed by the WIM. This study has several outcomes. Firstly,29

it demonstrates that the whole approach, based on the SPEM, previously used tosimulate the ground shaking for a destructive scenario earthquake, providesreliable results. Secondly, it shows that the model used to represent the crustalstructure beneath this area is realistic. Indeed, simplified models may not beadequate for predicting the site response. Moreover, the high amplitude displayedby the Catania station during the 1990 earthquake can be explained as a combinedeffect of site and structure-path.The second contribution to the project was the analysis of the environmentalseismic noise data (microtremors) acquired within the Catania municipal area inMay 1999, with the aim of improving the prediction of the seismic ground motionlocally. To this end, we followed Nakamura’s approach which, as proven, providesthe main features of the dynamic ground response through the calculation of thespectral ratio between the horizontal and the vertical components (i. e., H/V ratio)of background microtremors. We found (first Figure) that several sites exhibitirrelevant or weak amplification, i. e., sites which are located either on lava (forexample, the sites in the Catania centre or in the northern part of the municipalarea) or well-consolidated sedimentarysoils (Western districts of the city).The only sites which bear evidence ofsome amplification are located oneither fillings soils lying over lava, oron the fine alluvial deposits of theCatania Plain.Catania Project. Map of the Cataniamunicipal area showing the pseudoamplificationestimated from backgroundmicrotremor horizontal to vertical spectralratio (HVSR).The color and size of the circles indicatepeak frequency and amplitude of theHVSR, respectively. Blue and white circlesindicate sites with very low pseudoamplification(< 2) and flat response inthe low frequency range, respectively.Contour lines indicate the depth of thetop of the light-blue clays formation,which has been assumed as a possibleseismic bedrock. The background mapshows the simplified geotechnicalzonation.30

The Marche Microzonation Project is a two-year research project, whose generalobjective is the detailed microzonation of some selected cities of the MarcheRegion. The OGS contribution develops within the second year of the project. Theaim is to perform a detailed simulation of the ground motion and site responseanalysis for the cities of Treia (MC) and Cagli (PS). Numerical simulations areperformed using the SPEM. The reference event is a M=5.7 earthquake, and it isassociated to two normal faults located beneath the cities, respectively. The secondFigure shows a wavefield snapshot for the simulations performed for Treia.MarcheMicrozonationProject. Wavefieldsnapshot (P-SVacceleration) of theSPEM simulationperformed for thetown of Treia(Macerata, Marche,Italy). The locationsof the town andsource areindicated at the topand by the coupleof arrows,respectively.Within the project entitled Damage Scenarios in the Veneto-Friuli Area, theactivity of the first year aims at building-up a ground shaking scenario at a regionalscale for the area surrounding the town of Vittorio Veneto. The referenceearthquake 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 areconsidered. The dominant feature of the geological structure is the thrustcorresponding to the Alpago-Cansiglio highlands, the southern edge of whichfeatures a very steep change of elevation. The reference earthquake is associated tothis thrust. The particular location of the source, which is rather deep and right inthe middle of a structural discontinuity, makes it possible to tackle this study witha non classical approach, that is differentiating the surface structure and topelevation in different zones, i.e., the plane area, the foot-hill zone, the alpinevalleys, and the mountain area, respectively. The areas of maximum groundshaking predicted in this way agree very well with those observed in themacroseismic field (third Figure) even just by using a point source.31

Collaborations: National Group for the Defence Against Earthquakes (GNDT) andNational Group of Volcanology (GNV), belonging formerly to the National Councilof Research (CNR) and currently to the National Institute of Geophysics andVolcanology (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 ofGeophysics and Volcanology.ABDamage Scenarios in the Veneto-Friuli Area.The October 14, 1936 (M=5.8) “Cansiglio” earthquake.(A) Observed macroseismic field, and (B) peak groundaccelerations predicted numerically by the WIM.32

Seismic inversionCoordinator: Aldo VESNAVERThe Cat3D tomographic softwareG. BÖHMM. PERONIOThe software package Cat3D allows the 3D traveltime inversion by adaptiveirregular grids, for arbitrary recording geometry and combinations of differentwave types: direct, reflected, refracted and diffracted arrivals. Since it allows, forexample, the joint inversion of surface and VSP data, it is a valuable tool forcalibrating the seismic surveys with the well information.During the year 2000, the software commercialization was supported by the OGSpartners: Paneura (Trieste, Italy) and Fact (Houston, USA). Paneura had a booth atthe EAGE International Conference and Exhibition in Glasgow. Various copies ofCat3D were installed in Europe.A major improvement of the software efficiency was an aggressive use of thedynamic memory allocation, which allowed increasing the computational speed,the size of processed data and the model complexity. Several graphic features wereimproved during the year, and new Import/Export model formats Surfer ® andGeoQuest ® , which were added to the existing ones (GoCad ® and JasonGeosystems ® ). The software installation was made easier and its documentationsignificantly extended. A particular effort was spent for the software porting for allmajor Linux distributions (Slackware, Red Hat, Mandrake, Caldera, Debian) inlow-cost personal computers; of course, the Cat3D package runs also in differenthardware platforms (as IBM, Sun and SGI) under the Unix operating system.Furthermore, we added a user-friendly menu for defining grids with a circularsymmetry, which we prepared and tested for 3D VSP’s.Cover image ofthe user manual forthe tomographicCat3D package.33

Joint 3D inversion of P, S and converted wavesA. VESNAVERG. ROSSIDuring the last few years, ocean-bottom cables (OBC) were used at a large scale for3D marine surveys for recording the three components of the particle velocity andthe pressure waves. Also on land surface surveys and in VSP’s this technology isexpanding, since it allows detect and separate P, S and converted waves. P and Svelocity and, in particular, their ratio, are important lithological parameters toreconstruct porosity and pore pressure in the rocks. This information is importantto delineate boundaries and preferential migration paths both in hydrocarbonreservoirs and in shallow water-saturated rocks.In most cases, rock interfaces reflect both P and S waves, and convert part of theirenergy from one wave type into the other one. When these events are observableand can be reliably picked, we can enhance a lot the 3D lithological description ofthe Earth, because of the data redundancy with respect to the estimatedparameters. In fact, the unknowns describing the interfaces do not increase, andthose ones for the velocities just double; viceversa, if P, S, P-S and S-P waves areavailable, including both reflected and head waves, the traveltime data increase bya factor much larger than two. Thus, the Earth model is much better constrainedby the experimental data, and more robust with respect to errors in thetraveltimes.The joint inversion of P, S and converted waves has an additional advantage. Thesought velocity fields of P and S waves are almost decoupled, when consideringpure P and S arrivals: their only connection are the possible common reflectinginterfaces in the Earth. Converted waves provide new equations in the tomographyinversion, which directly relates the two velocity fields.We set up a software prototype for the elastic inversion by generalizing ourprevious acoustic code. The ray tracing algorithm is based on the Fermat’sprinciple, and determines the ray path for a given ray signature by a bending typeapproach. For example, in a P-S converted wave, we use the P velocities up to theconversion point, where we switch to the S field, for computing and minimizingthe traveltime along the ray path. The P and S velocities are estimated by an ART,SIRT or weighted SIRT algorithm.Time-lapse 3D tomographyA. VESNAVERF. ACCAINOG. DAL MOROG. MADRUSSANIG. ROSSIThe response in a seismic survey over a producing hydrocarbon reservoir changesduring the years, due to the different pressure conditions of gas and themovements of the gas/oil/water interfaces. This information is crucial foroptimizing the hydrocarbon production, locating the new wells in the unsweptareas, and where the hydraulic conductivity is expected to be adequate, as infractured or permeable formations. The 4D-TAIL Project is aimed at detectingthese variations of lithologic parameters by Amplitude Versus Offset (AVO) analysisand 3D tomographic imaging. The OGS partners are two oil companies, i.e.TotalFinaElf UK and Norsk Hydro, and the University of Milan. This project issupported by the European Union in the Thermie Programme.34

The joint inversion ofdirect, reflected andrefracted P wavesallows reconstructingthe velocity and depthin a model (above)without anyredundancy, unlike inthe elastic case (below).For a proper comparison of the differences in the seismic response, one has tocompensate all changes that do not depend on the reservoir itself, as the recordinggeometry and equipment. A factor usually neglected that we studied is the seasonalvariation of the seawater velocity, due to changing currents and the temperatureof the mixed layer. These variations can be of the same order of magnitude (or evenlarger) than those expected at the reservoir; furthermore, since they are spatiallyorganized, they can be attributed to the reservoir, so totally distorting the timelapseanalysis. In the Figure, we see that two 3D surveys acquired at the North seain 1989 and 1992 provide very different estimates for the sound speed in the seawater, obtained by the joint inversion of reflected and head waves. (We remark thatthese plots can be quite interesting for oceanographic studies too).Outside the reservoir, we do not expect variations of the seismic velocities and thereflector structure. Thus, we can impose that the Earth model in depth, obtained35

from different data vintages, is unique. At the reservoir, the P and S velocitiesshould 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 ofcoupled models, one of each vintage year, that are mostly identical, except in theupper layer and at the reservoir. When a proper amplitude-preserving surfaceconsistentprocessing is carried out, including a vintage cross-calibration, we cancarry out a pre-stack depth migration of each vintage, and compare the reflectivitychanges at the reservoir. AVO can add further details, and guide the design of thetomographic grid.Sound speed in the seawater estimated by the joint inversion ofreflected and head waves in the year 1989 (above) and 1992 (below)in the same area at the North Sea.Seismic tomography for environmental studiesG. ROSSIF. ACCAINOG. BÖHMG. DAL MOROG. MADRUSSANIM. PERONIOA. VESNAVERThe oil and gas industry pushed seismic technology at advanced levels bysignificant investments, which rarely are available for environmental studies.However, except for a scale factor, many practical problems encountered inhydrology within the shallowest Earth layers are very similar to those onesconsidered in the hydrocarbon reservoirs. Seismic tomography is a possibleexample: the inversion of velocity anomalies can be generally related to lateralfacies variations of the geological formations and, sometimes, to variation of otherproperties of hydraulic interest – as permeability and porosity. If both P and Swaves can be jointly inverted, various analytic expressions exists which relatedthese velocity fields to the fluids’ pressure and saturation.36

Transferring technology from the oil and gas industry to environmentalapplication is a goal we pursued within the MICA Project, funded by the “FondoTrieste”. We acquired a high-resolution 3D survey close to the Trieste airport, in anarea where the city aqueduct has several catchment wells. The tomographicinversion and imaging of this data showed not only a good correlation with theavailable stratigraphy from 3 wells, but also remarked the significant vertical andlateral variations of the layers overlying the water-saturated formations. This factproves 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 lesssignificant (and probably more expensive), but could break the impermeablecovers over the groundwater pool, allowing it to be polluted by industrial oragricultural activities.Complementary to the seismic surveys, we carried out also a Georadar and a geoelectricsurvey, for integrating the elastic and electro-magnetic parameters. Ofcourse, the penetration scale of the different techniques is quite different (butcomplementary), and their integration into a consistent physical model isongoing. Partner of OGS within the MICA Project is GeoKarst, which is ageochemical company located in the Trieste Area Science Park. This company iscomplementing the OGS activity by analyzing the water origin and fluxes bymeasuring the isotopes it contains.The stratigraphyof 3 water well (above)matches the pre-stackdepth migrated section(below) obtained bytomographic velocitiesin a high-resolution3D survey.37

Geophisical interpretationCoordinator: Angelo CAMERLENGHIThe activity of the group in 2000 was characterised by intensive data acquisition atsea and on land. At the same time data processing and interpretation have beencarried out in the OGS headquarters. Data acquisition, focussed to theunderstanding of the geology of continental margins, was mainly in Antarctica,within the projects WEGA (Wilkes Land Glacial History), LARSEN (DeglacialHistory of the Larsen Ice Shelf - Weddell Sea), ODP Leg 188 in Prydz Bay(M. Rebesco was shipboard sedimentologist), and TESAC (Tectonic and CenozoicEvolution of the South America-Scotia Plate Boundaries) sponsored by PNRA. Inaddition, 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 channelseismic reflection, chirp sonar, core logging data, gravity at sea, to structuralgeology data and lake bathymetry on land. Of particular relevance for the groupwas the continuing activity with the recently acquired Geotek multi-sensor corelogger, and the utilisation of the Datasonic chirp sonar in Antarctica.Processing and interpretation were on seismic, gravity, magnetic data, coresamples, core logging, downhole logging, and oceanographic data collected in theprevious years within the research programs sponsored by PNRA on the PacificMargin of the Antarctic Peninsula (Projects ODP Leg 178, SEDANO, SedimentDrifts of the Antarctic Offshore, and BSR, Bottom Simulating Reflectors), in theSouth Scotia Sea (Crustal Structure and Evolution of the Powel Basin), and in theRoss Sea (Cape Roberts Drilling Project and Evolution of the West Antarctic IceSheet). Research was conducted with the highest possible level of internationalcooperation and by supporting research fellowships at other research institutionssuch 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, Tierradel Fuego and the surroundings of city of Trieste. In parallel, we started a newproject as a joint venture with SOPROMAR in a contract with the ItalianGeological Survey to produce test sheets of the marine gravity maps of the coastalzones 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 theFriuli Venezia Giulia region. Another project has involved the identification ofkarstic cavities with micro-gravimetric techniques.Research applied to petroleum exploration included one project funded by AGIP onthe kinematics of salt deformation in the Eastern Mediterranean and distal Nilecone (in cooperation with the University of Parma and IGM, Bologna), and theparticipation in the Ormen Lange Verification project sponsored by NorskHydrothrough SINTEFF on the theme of gas hydrates.38

At the end of the year, we started a doctoral Program in Polar Sciences (applied topolar continental margin evolution) in cooperation with the University of Siena.Michele Rebesco hosted the Workshop “Seismic expression of contouritesand related deposits” in the framework of the IUGS-UNESCO InternationalGeological Correlation Programme n. 432 (Contourites, Bottom Currents andPalaeocirculation).We illustrate below the major scientific results achieved in the year 2000.Joint Italian/Australian Marine Geoscience Expeditionto the George V Land Region of East Antarctica(Wilkes Land Glacial History, WEGA project)G. BRANCOLINIM. BUSETTIC. PELOSL. SORMANIR. VIDMARA collaborative Italian PNRA/Australian AGSO-Antarctic CRC marine geoscienceresearch voyage to the George V Land sector of the East Antarctic continentalmargin 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 mstreamer length), 562 km of Chirper (2.5-7kHz and 8-21 kHz transducers, 1000marmoured cable) sonar data, 11 gravity cores, 28 piston cores, 18 surface grabs and11 short trigger cores were collected on the voyage. Water profile (CTD)measurements and water samples were collected at nine stations and seabedbottom photographs were made at 11 stations.The expedition discovered and mapped a shelf current-derived, sediment driftdeposit called the “Mertz Drift”, covering about 400 km 2 lying in an >800m deepsection of the George V basin west of the Mertz Glacier.On the continental rise multi-channel seismic data were taken across contouritedrift 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 apreliminary Mid-Pliocene age to truncated strata that crop out on the drift’ssteeper lee side. These data will provide crucial information about the Antarcticlate Cenozoic glaciations and useful site-survey support of a proposal sent to theOcean Drilling Program under the auspices of the SCAR-ANTOSTRAT project fordrilling key sites along the Antarctic margin.Deep Tow Chirper profile W-16 in the George V basin (continental shelf) andcore stations across the “Mertz Drift”. The drift is over 35 m thick and it is composedof laminated, anoxic, gelatinous olive green, siliceous mud and diatom ooze (SMO).39

Physical properties and seismic stratigraphy of ODPLeg 178 well sites, Antarctic Peninsula Pacific marginV. VOLPIA. CAMERLENGHIM. REBESCOP. CORUBOLOU. TINIVELLAC. DE CILLIAIn this work, sponsored by PNRA as participation to the scientific activity of theOcean Drilling Program, we have re-analysed the porosity, bulk density andseismic velocity information collected from three bore holes on the continentalrise of the pacific Margin of the Antarctic Peninsula. The purpose is to provide acomprehensive, composite digital data set of data readily available for futurestudies aimed at well-seismic correlation. The work originates from theoccurrence of overlapping sets of physical parameters and acoustic velocitycollected with different methods (downhole logging, core logging, laboratorydetermination, derivation from seismic data), and in different holes of the samesite. These data not always provide the same information.Composite vertical profiles of velocity (sonic logs, core logs, and measurements onsamples), density (RHOM - LDS corrected bulk density) and porosity (APLC - APSNear/Array limestone porosity corrected) have been obtained by combining datafrom different instruments and different holes. The comparison between core andlog porosity for site 1095 shows that, except for the lower part of the section,downhole porosity is systematically larger than core sample porosity due tothe poor open hole conditions encountered in a fine grained, generallyunderconsolidated formation.At site 1095 additional information on acoustic velocity comes from the velocitycheck-shots, obtained from a vertical seismic profile (VSP), while at site 1096additional information comes from acoustic tomographic inversion of travel times.These interval velocities can be compared with the nearest available stackingvelocity and the velocities obtained from core samples, at site 1095. The in situvelocity check-shots provide a more reliable velocity information than the stackingvelocity throughout the section, while the vertical seismic profile (VSP) provides areliable tie to the site survey MCS.40

ODP Leg 178 - Site LocationSite 1095 Porosity(g/cm 3 )ABSite 1095 Line 195-135A Site 1095NWSEmbsfTWT time (s)interval velocity (m/s)CDA) Location map of ODP Sites 1095, 1096, and 1101 (highlighted), together with allother sites drilled during ODP Leg 178. B) Comparison between the downholelogging (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 checkshots (VSP), stacking velocities and core log velocity. D) Vertical Seismic Profile and tiein two way travel times between lithostratigraphic and seismostratigraphic units.41

Orbitally-Controlled rhythmic sedimentationin the Wild Drift, Antarctica (ODP Leg 188, Site 1165)M. REBESCOThis research, conducted in collaboration with J. Gruetzner (Bremen University,Germany) is an outcome of the participation of an OGS researcher (MicheleRebesco) to the ODP Leg 188 in Prydz Bay – Cooperation Sea (Antarctica). Leg 188cruise began in Fremantle (Australia) on 10 January 2000 and ended in Hobart(Australia) on 11 March 2000. Three sites were drilled on continental shelf, slopeand 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 ofthe outlet of the Lambert glacier-Amery Ice Shelf system that today drains 22% ofEast Antarctica. The site cored a 999-m lower Miocene-Holocene section into anelongate sediment body (Wild Drift) formed by the interaction of westward-flowingcurrents with the sediment supplied from the shelf. Alternations with wavelengthsranging from cm to m size between a greenish grey diatom bearing clay facies anddark grey clay facies with silt laminations are apparent throughout the hole backto early Miocene time. Furthermore the greenish intervals are characterised bylower density, susceptibility and iron content. The dark grey intervals areinterpreted as contouritic facies deposited during maximum ice advances whereasthe greenish sediments indicate hemipelagic sedimentation under warmer climateconditions.Analysis of high resolution colour photo-spectrometer data reveals that the colourcycles are best described by the ratio of the reflectivity in the green colour bandand the average reflectivity (grey).Spectral analyses on depth and time series of the investigated parameters overselected intervals demonstrate that variance is dominated by orbital frequencies aspredicted by the Milankovitch theory. The detected obliquity and precession cyclesallow a refined evaluation of sedimentation rates.Subsidence at the Cape Roberts drill sites(Ross Sea, Antarctica) from backstripping techniquesL. DE SANTISG. BRANCOLINIThe tectonic subsidence of the western margin of the Victoria Land basin has beenestimated from the physical properties and ages of the sediments in the CapeRoberts Project drill cores 2/2A and 3, using backstripping techniques, assuming alocal isostatic compensation. The sediment load effects is removed from the totalsubsidence and the tectonic contribution through time at each location iscalculated.The analysis indicates a total tectonic subsidence of about 660 m at this locationbetween 34 Ma and the present time. Two main trends are defined, i) about 230m/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 verylow subsidence rate, but uplift within this period may have greatly affected theestimate.42

Core 1165B-14HComposite diagram showing the cyclicity at different scales nested together in thecolour record from Core 1165-14H. The cm-scale cycles are evidenced by colourbanding and lamination (see the interpreted black and white photo in the leftbottom). Such cycles are included within dm-scale cycles evidenced by lighteningupintervals. In turn, these cycles are included within dark grey facies (see the blackand white photo in the centre and the synthetic interpretation on its right). Finallym-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-spectrometerdata (see the ratio of the reflectivity in the green colour band versus the averagereflectivity on the right side of the diagram). Moreover (not shown here) largerscale (tens to hundreds of m) cycles are produced by the variation in ratio betweenthe thickness of the two facies of the m-scale couplets.43

The age and the calculated fast rates of the tectonic subsidence affecting thewestern Ross sea until 21 Ma is consistent with previous studies made in theCentral and Eastern Ross Sea that suggest an Oligocene age of the basin openingphase in those regions. Since 20 Ma, extrapolation of the tectonic subsidencecurves indicates a period of very low subsidence. Seismic reflection data across theVLB indicates that extensional tectonics was diachronous within the VLB and itwas progressively younger toward east and possibly toward south. We believe thatthe apparent major slow down of the overall subsidence rate after about 20 Ma maybe the result of subsequent uplift of the region and migration of the extensionaltectonics toward east and south.ATECTONIC SUBSIDENCEA. Tectonic subsidence curves obtainedusing backstripping technique at the CRP-2(squares) and the CRP-3 (circles) drill sites.The dashed curve represents theextrapolated tectonic subsidence of thebasement at CRP-3 site between 31 Maand present. This curve is inferred from thetrend at CRP-2 (from 30 to 21 Ma) and thedepth of the basement caused by thetectonics at present time at the CRP-3 site.The error bars indicate the range of theuncertainties in the paleo-depthinformation and age.B. line drawing of a composite seismicsection made by IT69, US 403 and US 404across the VLB about 5 km north of theCRP drill sites.WESTEASTB44

Cenozoic Evolution of the South Orkney MicrocontinentM. BUSETTIA. MARCHETTIThe South Orkney Microcontinent is one of the fragments of the South ScotiaRidge between the Antarctic and Scotia Plate. It is a key area for both Cenozoicpaleoclimatic and geodynamic studies as it is a remnant of the separation betweenAntarctica and South America about 26 Ma. The separation permitted the onset ofthe Circum-Antarctic current and the following climate isolation of the Antarcticcontinent.Due to the complexity of the geodynamic setting of the area and the differenttectonic regime (transform, convergence and divergence) in the surroundings, thesmall microcontinent has complicate geological evolution. Basins formation onthe microcontinent is related to the South Scotia Ridge fragmentation in the?Eocene/Oligocene time. The northern margin of the South OrkneyMicrocontinent is an obliquely convergent plate boundary dominated bytranscurrent condition exhibiting strain partitioning of convergent motionaccommodating by a thrust zone in the oceanic area and vertical strike-slip zoneat the border of the steep escarpment of the SOM. Between the microcontinent andthe Bruce Bank the plate boundary changes, exhibiting transcurrent andextensional regime.Structural scheme of the South Orkney Microcontinent and bathymetriccontours of the area. The continental shelf of the microcontinent is delimitedby the 1000-meter contour. Extensional tectonic in the Eocene/Oligocene timeproduced several north-south elongated basins. The northern margin of themicrocontinent 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 regionE. LODOLOR. GELETTIOnshore field geological and geophysical studies, and a multichannel seismicsurvey have been conducted in the last two years in the Tierra del Fuego region, inthe frame of an Argentinean-Italian scientific research. The main aim of thisproject was to analyse the regional geological setting of the Island and reconstructthe Cenozoic geodynamic evolution of an important segment of the SouthAmerica-Scotia plate boundary, called Magallanes-Fagnano fault system. This is amainly wrench lineament which cuts across the Island and runs from the Pacificentrance of the Magallanes Strait to the Atlantic coast of the Island. The LagoFagnano, located in the central part of the Tierra del Fuego, is an E-W-trendingmajor 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 theonshore prosecution of the lineament. In cross-section, this tectonic lineament isrepresented by sub-vertical faults and associated asymmetric basins, generated bysimultaneous strike-slip motion and transform-normal extension, as imaged bythe seismic profiles acquired off the Atlantic coast of the Island and in the centraland western Magallanes Strait.Data analyses support the interpretation that the Magallanes-Fagnano fault systemis remarkably transtensive in nature, and is structurally and temporallysuperposed on the older tectonic framework of the Tierra del Fuego (i.e., thecontractional system of the Magallanes fold and thrust belt), even if thedisplacement history of this fault system is unclear. The near parallelism amongthe younger and older lineaments suggests that the development of thetranstensional structures may have reactivated pre-existing weakened zonesformed by the Cretaceous-Tertiary shortening.Mapping the BSR on the South Shetland Margin(Antarctica) and assessing gas hydrate and free gasquantitiesE. LODOLOA. CAMERLENGHIG. MADRUSSANIG. ROSSIU. TINIVELLABottom Simulating Reflectors (BSRs) along the South Shetland continentalmargin have been first identified by OGS researchers on two multichannel seismicprofiles acquired by the R/V OGS-Explora (1990 Antarctic Campaign). A dedicatedsurvey was conducted on 1997 to purposely map the extent of the BSR on thismargin, and study the relationships between geological structure and gas hydrateand free gas distribution. Processing and interpretation of the collected grid ofhigh-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 thenorthern tip of the Antarctic Peninsula, consists of two distinct and superimposedtectonic regimes: an older regime is related to Mesozoic - Middle Cenozoicsubduction-related tectonism; a younger one is associated with a mainly46

Magallanes-Fagnanomaster faultTWT (s)Tectonic sketch of the Magallanes-Fagnano fault system across theTierra del Fuego Island, as revealed from the interpretation of seismicprofiles acquired at the Pacific entranceof 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 principalsub-vertical fault (the master fault), with associated asymmetricbasin, generated by simultaneous strike-slip motion and transformnormalextension along the strike of the fault system.47

(Top): Structural mapof the BSRs occurrencealong the SouthShetland margin,where the differencesin strength of the BSRshave been highlighted.(Bottom): Part of aseismic profile wherethe BSR crosses ananticline fold, withoutloss in amplitude andstrength.WE49

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 gasbearing sediments below. This transition is reflected in the velocity profile with aboundary at 4150 ms between a high velocity region (1670 m/s above) and a lowvelocity one (1500/1600 m/s below) (Figure B).A velocity structure obtained by prediction can be translated in gas hydrate andfree gas concentration structure. We used the method proposed by Tinivella(1999). The concentration is estimated by fitting the theoretical velocity to theexperimental P/wave velocity (derived by the prediction of the VSP in our case).The discrepancies between the inverted velocity profile and the velocity for waterfilled marine sediments are interpreted as due to the presence of the gas hydrate(where positive anomalies are present) and free gas (where negative anomalies arepresent). Figure C shows the distribution of the two phases: positive values (redcolours) are the gas hydrate concentration, while negative concentrations (bluecolours) are related to the percentage of volume occupied by free gas.AVSP velocity SectionBA) Position map of thestudy area. Wellslocation and seismicline position are shownin the close-upwindow.B) VSP velocity panel.C) Distribution of thetwo gas phases;positive values (redcolours) are the gashydrate concentration,while the negativeconcentrations (bluecolour).C50

Physical properties of sediment coresfrom the Antarctic continental marginsM. BUSETTIAntarctic paleoclimate and paleoenvironmental studies have a key role in theunderstanding of the global climate changing. Waxing and waning dynamic of theAntarctic ice coverage is the most important effect at high latitudes as response toclimatic variations. As sediment deposited on the continental shelf and rise recordthe ice fluctuations, they are an essential task in the paleoclimate study. Analysingthe acoustical and physical properties of sediment cores it is possible to investigateglacial and interglacial stages. P-wave velocity, bulk density and magneticsusceptibility are closely related to sediment composition and may reflect changesin grain-size distribution or in the ratio of terrigenous (quartz and clay) andbiogenic components. Generally terrigenous sediment characterise glacialdeposits, while biogenic material is present in the interglacial deposits.Acoustical and physical property logs of a marine piston core collected on thecontinental rise of the Antarctic margin. P-wave velocity and bulk density reflectthe grain size distribution: the higher values in the upper part of the core arerelated to silt, and even greater to sand, the lower values in the deeper partof the core are related to the clay fraction. Ice rafted debris (black spots in thevisual log) produce clear spikes in the magnetic susceptibility measurements.51

Backstripping modelling in the frame of theStratigraphical Development of the Glaciated EuropeanMargin (STRATAGEM) - EU projectL. DE SANTISS. CERAMICOLAA. CAMERLENGHIThe Project is funded by the European Community within the 5 th framework andit 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) areto address problems related to the mid-Cenozoic to Recent development of theglaciated north European margin, that extends from northern Norway to centralIreland. The end product of the project will be the development of a MarginEvolution Model, to assess the interactions of sedimentary processes that haveproduced the character of the present day margin and the forcing factors (such asclimate, 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 theIMAGES 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 datacollection (and processing) in the Faroe Island continental margin (R/V DANAcruise);2) 2D flexural, post-rift backstripping modelling on several transects along thelength of the continental margin, in particular in the Vøring, in Shetlands-Faroe Islands and in the Hebrides margins. The models will constrain themore-qualitative Margin Evolution Model, and provide insights into factorssuch as uplift and subsidence that have been among the crucial controls onmargin development. The observed stratigraphy is modelled using flexuralbackstripping combined with decompaction and reverse thermal subsidencecalculations by mean of a commercial software package (Flex-Decomp byBadleys Ltd.-UK). Reliable direct palaeobathymetry information from drill sitesand indirect palaeobathymetry markers, such us erosion surfaces, are used toconstrain the subsidence history. During the first year of the project severaltests have been carried out to verify the input parameters (e.g. stretching factorand the lithosphere elastic thickness).3) the comparison with the Antarctic glaciated margins, that will place the resultsof the STRATAGEM study in a global perspective.52

Bathymetric map of the North Atlantic continental margin studied in the STRATAGEMframe. WP1 is the Work Package 1 study area (the Norwegian margin); WP2 is the WorkPackage 2 study area (the South Shetland-Faeroe margins); WP3 is the Work Package 3study area (the Rockall Trough and Porcupine Basin).Earth gravity field: measurements, data processingand interpretationC. ZANOLLAF. PALMIERIF. CORENC. DE CILLIAOGS has a long tradition in gravimetry (i.e. the international gravity stationnetwork IGSN71, Italian gravity map, marine gravity surveys in the Mediterraneansea). Gravity surveys (land or marine) can be managed from planning, to fieldacquisition, processing and interpretation. The INTE group has the responsibilityto manage and operate three LaCoste-Romberg gravity meters (one model D andtwo model G), one underwater gravity meter LCR model H, one marine surfacegravity meter Bodenseewerk KSS31. These allow us to cover all the possibleapplications 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 ServizioGeologico Nazionale to carry out two marine gravity surveys in areas locatednear Rome.53

The purpose is to merge the land and marine gravity data to obtain a higherspatial definition of the gravity anomalies near the coastline and a gravity mapthat is overlapped with the geological maps at scale 1:50.000. In particular wehave been required an underwater gravity survey and a surface marine gravitysurvey. The first survey has been completed while the second one will becarried out in february 2001.2) Two micro-gravimetry nets have been established in order to study thetemporal gravity variations associated with: a) water table fluctuations to studythe effective porosity of the geological formations involved (Fagagna area); b)the subsidence problems that affect some districts of the city of Trieste; thissurvey is jointly carried out with SAR techniques.In the near future we will repeat measurements in a network located inseismically active areas of Friuli-Venezia Giulia.3) Several micro-gravity surveys have been planned in order to detect thepresence of cavities in the Carso area surrounding the city of Trieste: Onesurvey is ongoing in the “Grotta Doria”, with the aim to model the gravityanomalies and to compare the results obtained with several geophysicaltechniques 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 ofAntarctica withsuperimpose the ITASEtraverse along whichthe gravity profile hasbeen acquired (above).Free air gravity profileacquired across theWilkes Basin, EastAntarctica (below).Free Air gravity anomaly (mGal)54

Synthetic Aperture Radar (SAR) remote sensingF. CORENR. VIDMARP. STERZAIHorizontal velocityfield of theLigosullo landslide(northeast Italy)derived by SARinterferometry(yellow contours)superimposedto a aerialimage of the area.Since 1996 OGS developed within the INTE group its own research line inSynthetic Aperture Radar (SAR) remote sensing. The activity is now mainlyaddressed to interferometry and analytical products generation using ERS-1 andERS-2 satellites.Research activity have been focused on two main tasks:1) Monitoring terrain deformation (landslide) using differential interferometrytechniques and analysis of the hydrological setting using SAR remote senseddata. In this field TS-SAR is the major project where SAR interferometry hasbeen used to monitor ground deformation in the area of Trieste (Italy) in theperiod between 1996-2000 for the Civil Protection Department of theMunicipality. A specific investigation has been carried out in industrialised andurban area to assess the possibility of a continuous monitoring of inferredsubsiding phenomena. A set of complex interferograms has been computed inorder to identify sliding and subsiding areas and to verify the general urbanstability. A validation procedure on the interferogram has been appliedconsidering only pixels characterised by high coherence in all thecombinations. These pixels represent permanent backscatter and are mainlyassociated to civil structures and buildings. The displacement history of threewarehouses has been computed on the temporal basis of 23 month. At thepresent, a validation has been carried out only by ground observation withoutelevation measurements. Other minor project has been also carried out tomonitor and detect landslides in the Friuli area (see figure).2) Study of the glacial setting of East Antarctica (STARGLASS project financed byPNRA Italian National Antarctic Program) and Northwestern sector ofAntarctic Peninsula (a self sustained research activity). Main goal of bothprojects is the computation of the ice velocity fields and digital elevation modelof outcrop areas. Polar regions play an important role in the globalenvironment. The potentiality ofSAR interferometry for themonitoring of high latitude areas istoday a well understood geophysicaltool and represents a flexible andpowerful method to study large polarsectors at low specific cost. InSTARGLASS project we have usedpairs of tandem images of satellitesERS-1 and ERS-2 synthetic apertureradar (SAR) of the David glacier, EastAntarctica, for the purpose to outlinethe grounding line. All the SAR radardata have been provided under theVECTRA project cover (EuropeanSpace Agency AnnouncementOpportunity 3.108) in raw format.55

AdministrationCoordinator: Dario ColonnelloF. PETRONIOThe activities of the administration office were, basically, to manage the purchase ofraw material, scientific instruments, services and consumables necessary to carry outthe various projects; personnel expenses for traveling to working sites and scientificmeetings and conventions; invoices and statements of accounts and the legal aspectsof the projects; and the Department’s inventory.The total turnover of the Department in 2000 was approximately 3.7 milion Euro’s ofwhich we effectively spent 1.7 milion Euros. The real income related to specificprograms amounted to more than 3.2 milion Euros.56

PublicationsWave modelingARNTSEN, 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 wavein water-saturated Nivelsteiner sandstone, submitted to Geophysics.CARCIONE, J. M., ARNTSEN, B., AND CAVALLINI, F., 2000, Simulation of ultrasonic wavesin a natural sandstone. In Bermudez, A. et al. (Eds.), Mathematical and Numerical Aspectsof Wave propagation, SIAM, 128-132.CARCIONE, J. M., AND SERIANI, G., 2000, Numerical simulation of wave propagation infrozen porous media. In Bermudez, A. et al. (Eds.), Mathematical and Numerical Aspectsof 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 porefluidpressures: effects on seismic attributes, Geophys. Prosp., 48, 521-537.CARCIONE, J. M., AND POLETTO, F., 2000, Sound velocity of drilling mud saturated withreservoir gas, Geophysics, 65, 646-651.CARCIONE, J. M., AND GANGI, A., 2000, Gas generation and overpressure: effects onseismic attributes, Geophysics, 65, 1769-1769.CARCIONE, J. M., 2000, A model for seismic velocity and attenuation in petroleum sourcerocks, Geophysics, 66, 1080-1092.CARCIONE, J. M., AND SCHOENBERG, M., 2000, 3-D ground-penetrating radarsimulation and plane wave theory, Geophysics, bf 65, 1527-1541.CARCIONE, J. M., 2000, AVO effects of a hydrocarbon source-rock layer, submitted toGeophysics.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 anisotropicporo-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-reflectorconcept for ground penetrating radar modeling, submitted to Geophysics.CARCIONE, J. M., AND TINIVELLA, U., 2000, The seismic response to overpressure: amodeling methodology based on laboratory, well and seismic data, submitted toGeophys. Prosp.CARCIONE, J. M., CAVALLINI, F., AND MAINARDI, F., AND HANYGA, A., 2000, Timedomainseismic modeling of constant Q-wave propagation using fractionalderivatives, Pure and Applied Geophysics, in print.CARCIONE, J. M., AND CAVALLINI, F., 2000, A semi-analytical solution for the propagationof 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 drillstrings, 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 thesea-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, Seismicmodeling, A review for Geophysics, submitted.CARCIONE, J. M., AND GEI, D., 2001, A seismic modeling study of Vostok lake, submittedto Journal of Glaciology.CARCIONE, J. M., AND CAVALLINI, F., 2000, Poisson’s ratio at high pore pressure, NorskHydro, E&P research centre, Bergen, NH-report R-089643.CARCIONE, J. M., MARCAK, H., SERIANI, G., AND PADOAN, G., 2000, GPR modelingstudy in a contaminated area of Krzywa airbase, Geophysics, 65, 521-525.CARCIONE, J. M., AND TINIVELLA, U., 2000, A modeling study based on laboratory, welland seismic data, Norsk Hydro, E&P research centre, Bergen, NH-report R-089737.CARNEVALE, G.F., CAVALLINI, F., and F. Crisciani, 2000, Dynamic boundary conditionsrevisited. J. Phys. Oceanogr., In press.CAVALLINI, F., Reply to comment by K. Helbig on “The best isotropic approximation of ananisotropic 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 ofsand/clay mixtures, Pure and Applied Geophysics, 157, 811-827.HANYGA, A., AND CARCIONE, J.M., 2000, Numerical solutions of a poro-acoustic waveequation 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 ofshaley sandstones, 63th Ann. Internat. Mtg. Europ. Assoc. Expl. Geophys., ExpandedAbstracts.POLETTO, F., CARCIONE, J. M., LOVO, M., AND MIRANDA, F., 2000, Acoustic velocity ofSWD bore-hole guided waves, submitted to Geophysics.POLETTO, F., AND CARCIONE, J. M., 2000, On the group velocity of guided waves in drillstrings, 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 spectralelement method. J. Comp. Acoustics, in print.PRIOLO, E., 2000, 2-D spectral element simulation of the ground motion for acatastrophic 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 forsite 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 andfree-gas saturation from log and sesimic data, The Leading Edge, in print.SERIANI, G., 2000, An iterative time-stepping method for solving first-order timedependent 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 foracoustic wave modelling. In: Onate, E. et al (Eds.), ECCOMAS 2000: Finite ElementSchemes for Waves Problems. CIMNE, Barcelona (Spain), 13 pp., CD-ROM.VALLE, S., AND CARCIONE, J. M., 2000, Detection of liquid contaminants in the subsoilusing the GPR technique, submitted to J. Appl. Geophys.58

Seismic inversionROSSI, G., AND VESNAVER, A., 2000, Joint 3D traveltime inversion of P, S and convertedwaves, Journal of Computational Acoustics, 8, (in stampa).ROSSI, G., VESNAVER, A., AND PETERSEN, S., 2000, Anisotropy detection by tomographyand polarization analysis in a 3D three-component VSP, First Break, (in stampa).BÖHM, G., GALUPPO, P., AND VESNAVER, A., 2000, 3D adaptive tomography by Delaunaytriangles and Voronoi polygons, Geophysical Prospecting, 48, 723-744.BÖHM, G., MADRUSSANI, G., ROSSI, G., AND VESNAVER, A., 2001, Ray footprint andredundancy in seismic tomography, Journal of Seismic Exploration, 10, (in stampa).ROSSI, G., MADRUSSANI, G., AND VESNAVER, A., 2000, Adaptive 3D joint inversion ofdirect, 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 WaterEnvironment, 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, Depthimaging and velocity calibration by 3D adaptive tomography, First Break, 18, 303-312.Geophysical interpretationBARKER, P.F., CAMERLENGHI, A., and the ODP Leg 178 Shipboard Scientific Party, inpress. 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° InternationalSymposium 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. Relationshipamong X-Ray Lithofacies, Magnetic Susceptibility, P-wave Velocity and Bulk Density inCore ANTA95-89C (Ross Sea, Antarctica): First Results. Proceedings of the Workshop“Ricostruzioni paleo-climatiche dai sedimenti marini del MarediRoss (Antartide) edell’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 AntarcticEarth Sciences, New Zealand Journal of Geology and Geophysics, Royal Society of NewZealand.BUSETTI, M., ZANOLLA, C. and MARCHETTI, A. in press. Geological Structure of theSouth Orkney Microcontinenvt. Proceedings of the workshop: “Broad Band Observationsand 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 AntarcticPeninsula Pacific Margin: modelling flexure and decompaction with constraints from ODPLeg 178 initial results. New Zealand Journal of Geology and Geophysics.COREN, F., LODOLO, E., CECCONE, G. submitted. Age Constraints for the Evolution ofthe Northern Powell Basin (Antarctica). Bollettino di Geofisica Teorica ed Applicata.DE SANTIS, L., DAVEY, F., PRATO, S., and BRANCOLINI, G,. submitted. Subsidence at theCRP drillsites from backstripping techniques. Terra Antartica, Scientific Report on CRP-3.DI VINCENZO, G., CABURLOTTO, A., and CAMERLENGHI, A., submitted. An 40 Ar- 39 Arinvestigation of volcanic clasts in glaciogenic sediments at Sites 1097 and 1103 (ODP Leg178, 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: gravityand magnetic interpretation along a traverse across the Wilkes Basin. Earth and PlanetarySciences 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 indicatenon-steady state Antarctic bottom water production in the Holocene. Nature.LA MACCHIA, C. and DE SANTIS, L., in press.Seismostratigraphic sequences analysis inthe Prydz Bay area (East Antarctica). In the Proceeding volume of the Italian workshop onAntarctic Paleoclimate, Trieste Nov. 1998. Terra Antartica.LODOLO, E. and CAMERLENGHI, A., 2000. The occurrence of BSRs on the AntarcticMargin. In: M.D. Max (Ed.): Natural Gas Hydrate in Oceanic and PermafrostEnvironments, 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., inpress. 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., ANDFONTOLAN, G., in press, Sedimentary Processes and Glacial Cycles on the Sediment Driftsof the Antarctic Peninsula Pacific Margin: Preliminary Results of SEDANO-II Project, In:J. Gamble, D. Skinner, & S. Henrys (Ed), Proceedings of the VIII° InternationalSymposium on Antarctic Earth Sciences, New Zealand Journal of Geology andGeophysics, Royal Society of New Zealand.M. BRAUN, F. RAU, F. COREN AND H. SAURER. Submitted. Delimiting glacier drainagebasins using remote sensing data of various sensor types and digital elevation models ofdifferent accuracies. Journal of Glaciology.PROTOPSALTI, I., IMMORDINO, F., DE SANTIS, L. FANZUTTI, G. P., in press. Sedimentgrain 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, NewZealand 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, SouthhamptonOceanography Centre, U.K.REBESCO, M., DELLA VEDOVA, B., CERNOBORI, L., AND ALOISI, G., 2000. AcousticFacies 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, AntarcticPeninsula Pacific Margin. In: Stow D.A.V., Pudsey C.J., Howe J., & Faugeres J.C. (Ed), Atlasof 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 interhemisphericcorrelation of climatic events. Earth Planet. Sci. LettSHIPBOARD SCIENTIFIC PARTY, 2000. Leg 188 Preliminary Report: Prydz Bay -Cooperation Sea, Antarctica: glacial history and paleoceanography. ODP PreliminaryReport, 188 [online] Available from:60

TINIVELLA, U. AND LODOLO, E., 2000. The Blake Ridge BSR transect: tomographicvelocity 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 velocityanalysis 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., ANDTINIVELLA, U., submitted. Physical properties and seismic stratigraphy, continental risesites 1095, 1096, and 1101, ODP Leg 178, Antarctic Peninsula. In Barker, P.F., CamerlenghiA., Acton, G.A. and Ramsay, T. (Eds.) Proc. ODP, Sci. Results, 178.61

Presentations at meetings and conventionsSeismic data processingWARDELL N., DIVIACCO P., SINCERI R., 2000, Pre-Processing Corrections on Very HighResolution 3D Marine Seismic Data, 62 nd Annual International Meeting EAGE, Glasgow2000, Expanded Abstracts, P-130.DIVIACCO P., SINCERI R., WARDELL N., 2000, Estensione 3D per tecniche dipreprocessing di dati sismici marini ad alta risoluzione, GNGTS, Rome 2000.Wave ModelingCARCIONE, J. M., GUREVICH, B., CAVALLINI, F., AND SERIANI. G., 2000, A generalizedBiot-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 wavesin a natural sandstone, Fifth International Conference on Mathematical and NumericalAspects of Wave propagation, Santiago de Compostela (Spain), July 10-14CARCIONE, J. M., AND SERIANI, G., 2000, Numerical simulation of wave propagation infrozen porous media, Fifth International Conference on Mathematical and NumericalAspects of Wave propagation, Santiago de Compostela (Spain), July 10-14.CARCIONE, J. M., CAVALLINI, F., AND MAINARDI, F., 2000, Modeling constant-Q wavepropagation 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-domainseismic modeling of constant Q-wave propagation using fractional derivatives, WorkshopMeeting 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 seismicproperties, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2405-2408.CARCIONE, J. M., GANGI, A., AND H. B. HELLE, 2000, Gas generation, overpressure andseismic properties (CD-Rom), III Conferencia Latinoamericana de Geofisica, Villahermosa,Mexico.CARCIONE, J. M., CAVALLINI, F., GUREVICH, B., AND SERIANI, G., 2000, A generalizedBiot-Gassmann model for the acoustic properties of frozen porous media, Workshop onSeismic Signatures of Fluid Transport, Berlin, Germany.CARCIONE, J. M., CAVALLINI, F., AND SERIANI, G., 2000, Biot-type three-phase modelingof seismic wave propagation, EGS XXV General Assembly, Nice, France.CARCIONE, J. M., AND SERIANI, G., 2000, Electromagnetic properties of fluidcontaminated soils using composite models, EGS XXV General Assembly, Nice, France.CAVALLINI, F., BOBBIO, M., PETTENATI, F., AND SIROVICH, L., 2000, ConVor, A newgenerationmethodology for tracing objective and reproducible iso-seismals: the case ofFeb. 28, 1925 Charlevoix earthquake in Canada. In EOS, Proceedings of AGU SpringMeeting, May 30 - June 3 2000, Washington, DC.FOSTER, M., LODOLO, E., TASSONE, A., GELLETTI, R., CARCIONE, J. M., 2000, Seismicstructure and sedimentary setting of the souther Magallanes Basin off the Tierra del FuegoIsland, Workshop Contiental Shelf, Buenos Aires, Argentina.HANYGA, A., AND CARCIONE, 2000, Numerical solutions of a poro-acoustic wave equationwith generalized fractional integral operators, Fifth International Conference onMathematical 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 poroacousticwave equation, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., ExpandedAbstracts, 2337-2340.62

POLETTO, F., LOVO, M., AND CARCIONE, J. M., 2000, Acoustic velocity of drilling mudand SWD borehole guided waves, 70th Ann. Internat. Mtg., Soc. Expl. Geophys., ExpandedAbstracts, 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 - 4February, 2000, Auckland, New Zealand. 8 pp., CD-ROM.PRIOLO, E., MICHELINI, A., AND LAURENZANO, G. 2000, Rapporti spettrali H/V dirumore sismico ambientale nel Comune di Catania. XIX Convegno GNGTS, Roma 7-9novembre.PRIOLO, E. 2000, Modellazioni numeriche del moto sismico del suolo a Catania e misuredi rumore. Corso CISM-APT: “La riduzione del rischio sismico nella pianificazione delterritorio (l’input sismico, le modellazioni, i valori di amplificazione), Lucca, 15-17novembre.TINIVELLA, U., AND CARCIONE, J. M., 2000, Estimation of gas hydrate concentration andfree 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 acousticwave 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 codicegrafico per tracciare isosiste obiettive e riproducibili. In Convegno Nazionale GNGTS,Roma, 7 - 9 novembre.Seismic inversionBÖHM, G., GALUPPO, P., AND VESNAVER, A., 2000, Multiresolution in 3D seismictomography 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 surfaceand 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 3Dadaptive tomography: 70th Annual Internat. Mtg., Soc. Expl. Geophys., ExpandedAbstracts, Calgary, 2269-2272.ROSSI, G., MADRUSSANI, G., AND VESNAVER, A., 2000, Tomographic inversion of thewater layer in the 4D analysis: 70th Annual Internat. Mtg., Soc. Expl. Geophys., ExpandedAbstracts, Calgary, 1287-1290.TINIVELLA, U., ACCAINO, F., CAMERLENGHI, A., 2000, Gas hydrate and free gasdistribution 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, Ilproblema “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 dianomalie di velocità tramite tomografia a riflessione: Atti 19° Convegno Nazionale GNGTS,Roma.ROBEIN, E., LAFOND, C., MAZZOTTI, A., AND VESNAVER, A., 2000, Time-lapse analysisby 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 improntedei 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 diapplicazione nella piana alluvionale dell’Isonzo: Riassunti dell’80 Riunione estiva dellaSocietà 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 GeologicaItaliana, Trieste, 414-415.Geophysical interpretationBUSETTI, M., 2000. WEGA (Wilkes Land) Site Survey for ODP proposal 482 AGU 2000Spring 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 withConstraints 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 onthe mechanisms of deformation of the Eastern Mediterranean Ridge. EAGE Conference onGeology 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 Sedimentationat 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 toEos, p. OS22A-05.LODOLO, E. AND TASSONE, A., 2000. The South America-Scotia Plate Boundary in theTierra del Fuego Island: A Geophysical and Geological Study. 31th InternationalGeological Congress, Rio de Janeiro, August 2000.LODOLO, E. TASSONE, A. MENICHETTI, M. COREN, F. STERZAI, P., 2000. Decipheringthe morphostructure of the Tierra del Fuego region from remote-sensing and geophysicaldata. 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 ofSediment Drifts from the Western Continental Rise of the Antarctic Peninsula, 25° EGSAssembly (Nice, 25-29/04/00, Abstracts).ODP LEG 188 SHIPBOARD SCIENCE PARTY (2000), Lithostratigraphy of ContinentalShelf, Trough-Mouth Fan and Sediment Drift Deposits, ODP Leg 188, Prydz Bay, EastAntarctica, AGU 2000 Spring Meeting, Washington, DC 30/05-03/06/2000, Supplement toEos, May 9, 2000, p. S273-274.ODP LEG 188 SHIPBOARD SCIENCE PARTY (2000), Physical Property Changes as a Proxyfor East Antarctic Sedimentation: First Results From ODP Leg 188 (Prydz Bay), AGU 2000Spring 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, . EAGEConference on Geology and Petroleum Geology of the Mediterranean and circum-Mediterranean Basins, Malta 1-4 October 2000. Extended Abstract Book.64

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 nelMare 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 OceanographyCentre, U.K.COREN, F., VIDMAR, R., STERZAI, P., 2000. Utilizzo di dati SAR per applicazioni diprotezione civile nel comune di Trieste: il progetto TS-SAR – Atti della 3 ConferenzaNazionale ASITA – Napoli – Vol 1 pp. 627 – 632CAPRA, A., COREN, F., FREZZOTTI, M., MANCINI, F., STERZAI, P., VIDMAR, R., 2000.Verso Il Monitoraggio Ambientale dell’Antartide A Scala Globale –Il Progetto Vectra – Attidella 3 Conferenza Nazionale ASITA – Napoli – Vol 1 pp. 489 – 496COREN, F., STERZAI, P. VIDMAR, R., 2000. Interferometric Analysis of David Glacier (EastAntarctica) – ERS ENVISAT Symposium 2000 – Goteborg – ESA.65

Book reviewsVESNAVER, A., 2000, Review of the book “Numerical methods for wave equations ingeophysical 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 videoOGS co-produced an educational video entitled “PERCHÉ L’ANTARTIDE”, in which themain scientific activities in the field of earth sciences carried out in Antarctica aredescribed with the aid of original video material. The video was produced also by theNational Antarctic Museum (MNA), and CNR. The english version of the video has beenpresented at the Italian stand at the XXXI International Geological Congress held in Riode 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’AntartideTitle of the English version: Why AntarcticaProduced by: CNR-IRPI-RCS/OGS/MNAProduction: CNR-IRPI Reparto di Cinamatogrtafia SceintificaDirected by: Teodoro MercuriScience advisors: A. Camerlenghi, M. Parotto, F. Salvini, F. TalaricoEditing: E. ValenteOriginal Music: V. RiccaArchive Images: MURST - PNRA, ENEA, OGSComputer Graphics: IMMAGINE SaS - CosenzaVHS PAL - Color - 37 MinutesPrinted in the year 200066

VisitorsPeter 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, visitingGiuliano Brancolini within the Cape Roberts Drilling Project.Belinda BROWN, School of Earth Sciences, University of Sydney, Sydney,AUSTRALIA, visiting Laura DeSantis within the WEGA projectAtle NYGÅRD, Department of Geology, University of Bergen, Bergen (Norway),visiting Laura De Santis within the STRATAGEM project.International seminarsin solid earth geophysicsChairman: Fabio CAVALLINIGiovanni SANTARATO (University of Ferrara, Italy)Electrical tomography for environmental geophysics and cultural heritage: someexamplesMichele REBESCO (OGS, Trieste, Italy)Glacial history and paleoceanography: preliminary results of the cruise “ODP Leg188” and “WEGA” in AntarcticaJurgen MIENERT (University of Tromso, Norway)Storegga slide gas hydrate drilling on the mid-Norwegian marginJeno GAZDAG (OGS, Trieste, Italy)The effects of regularization on 3-D pre-stack migrationSteven R. PRIDE (University of Rennes, France)Electroseismic wave phenomenaSteven R. PRIDE (University of Rennes, France)The theory of poroelasticity applied to exploration seismologyGiovanni P. GREGORI, IFA (CNR, Roma, Italy)The origin of the magnetic field and of the endogenous energy of the Earth andof celestial bodiesGabriele PAPARO, IDAC (CNR, Roma, Italy)Acoustic emission as a diagnostic tool in geophysicsAlfredo MAZZOTTI (University of Milan, Italy)Principles of AVO exploration67

Fred DAVEY (Institute of Geological & Nuclear Sciences, Wellington, NewZealand)Geophysical Investigation of a Modern Continental Transpressional Orogen: theSouthern Alps, New ZealandProfessor Sierd CLOETINGH (Vrije Universiteit, Amsterdam, The Netherlands)Intraplate tectonics and continental lithosphere evolution: models and constraintProfessor Sierd CLOETINGH (Vrije Universiteit, Amsterdam, The Netherlands)Sedimentary basins and continental topography: from the Mediterranean to theCarpathian regionProfessor Sierd CLOETINGH (Vrije Universiteit, Amsterdam, The Netherlands)Continental rifts and rifted continental marginsDr. Maurizio BATTAGLIA (Stanford University, USA)GPS applications in the Earth SciencesDr. Maurizio BATTAGLIA (Stanford University, USA)Temporal gravity investigations at Long Valley calderaDr. Maxim Yu. MOSKALEWSKY (Institute of Geography, Moscow, Russia)Ice formation zones: probably the most sensitive indicators of short-term globalchangesDr. Maxim Yu. MOSKALEWSKY (Institute of Geography, Moscow, Russia)Active Antarctic coastal zones as objects for remote sensing monitoring ofenvironmental changesPeter F. BARKER (British Antarctic Survey, Cambridge, UK)The Antarctic Circumpolar Current and Antarctic glaciationKlaus HELBIG (Hannover, Germany)Seismic anisotropy for the rest of usKlaus HELBIG (Hannover, Germany)Singularities of the phase velocity of anisotropic media: specific examples fororthorhombic media.68

About Trieste, ItalyOverwiewTrieste is geographically at the center of Europe and is a crossroads betweenthe Central-European and Mediterranean cultures. Located on a strip of landwhere the white Karst cliffs plunge abruptly into the sea, Trieste has been stronglyaffected by its history both in terms of architecture and life style.Evidence of the contact between different ethnic groups can be found in the localdialect, in the family names of the inhabitants, and in the local cuisine that cannotbe found elsewhere in Italy. In its welcoming restaurants, the savory flavors of mid-European dishes, or the simple cooking typical of the Northern Adriatic, thehealthy and colourful cuisine of the south, or delicate seafood dishes can beexperienced.The spirit of Trieste can be found in its cafes, pubs and buffets, which are thetraditional meeting places in the life of the city. Cafes in fact are parlours whereyou 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 theatersThere are many historical buildings, the most famous is probably the romanticMiramare castle, the residence of the luckless Maximilian of Habsburgand Charlotte of Belgium. Moreover, Trieste is rich in prestigious museumsboasting numerous collections of great artistic value, and in theaters,such as Giuseppe Verdi Opera theater, opened by 1801, which is one ofthe centers of cultural life with its winter opera and concert season, andthe Operetta Festival during the summer.69

Trieste and scienceTrieste is also a city of science, with a prestigious University and many worldrenownedlaboratories, like the International Center for Theoretical Physics, theInternational Center for Genetic Engineering and Biothechnology, the ResearchArea Park with its Synchrotron, as well the School of Modern Languages forInterpreters and Translators, and the Osservatorio Astronomico. The OGS NationalInstitute is located in a beautiful greenarea on the Karst plateau near the GiantCave, visited by thousands of touristeach year.A bit of historyThe Roman origins of Trieste are stillvisible in the well preserved remainsnear San Giusto Castle, which is thesymbol of the city, together with theRomanesque Cathedral, and theremains of the Roman Theater erectedby Quinto Petronio Modesto in the IICentury A.D.Because of its geographical position, asa crossroads between important traderoutes, possession of the city was contended by Venice, France and then Austria.After realizing the commercial importance of Trieste, and as a consequence of thedecline 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 mostimportant ports in Europe.70

Near TriesteOne cannot miss a visit to Venice, 150 km from Trieste. The splendid beaches ofSistiana, Grado and Lignano are 20, 50 and 100 km away, respectively. Near Gradois the ancient Roman town of Aquileia, with a museum, well preserved open-airruins 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 itsInternational Center for mechanical Sciences, is 80 km away.Transportation and travel to TriesteBy air: Trieste International Airport is 33 km from the city. There are direct flightsto/from Rome, Milan, Genoa, Munich. A shuttle bus is available to town. Inaddition, 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 mainhotels.By car: Trieste is connected to the national and international motorways, and theA4 Venice-Trieste and Trieste-Ljubliana highways.By sea: there is a seasonal ferry service to/from Greece.Photo by Gabriele Crozzoli - Trieste71

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