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S eismic wave P ropagation and I maging in C omplex media: a E uropean network. TASK GROUP SMALL SCALE Involved SPICE Institutions and Researchers ETHZ Zürich, Switzerland (Holliger, Sidler) OGS Trieste, Italy (Seriani, Carcione, Sidler, Pacchiani)
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Seismic wave Propagation and Imaging in Complex media: a European network • TASK GROUP SMALL SCALE • Involved SPICE Institutions and Researchers • ETHZ Zürich, Switzerland (Holliger, Sidler) • OGS Trieste, Italy (Seriani, Carcione, Sidler, Pacchiani) • Univ. College Dublin, Ireland (Bean, Lokmer, O‘Brien) • U. Hamburg (Dahm, Tessmer, Cesca, Nguyen, Heimann, Dobson) • Univ. Naples, Italy (Zollo, Murphy) • External collaborations • CNRS Clermont-Ferrand, France (Battaglia) • INGV, Italy (Braun, Saccorotti) • Univ. München, Germany (Wassermann) • Schlumberger Research Cambridge (Robertsson, Chapman)
SubgroupsTG Small Scale VOLCANOES1. Wave propagation in volcanic aeras2. Modeling of volcano seismic sources3. Improvement eruption diagnostic tools MUSHY SEAFLOOR1. Modeling of wave propagation in sea-floor mushy layers2. Improving interpretation of seismic observations in marine environments
CollaborationsTG Small Scale Subgroup Volcanoes Subgroup Mushy Seafloor SPICE TG Small Scale Univ. College Dublin (Bean, Lokmer, O’Brien) ETHZ Zürich (Holliger, Sidler) Univ. Hamburg (Dahm, Tessmer, Cesca, Nguyen, Heimann, Dobson) Univ. Naples (Zollo, Murphy) OGS Trieste (Seriani, Carcione, Sidler) J. Battaglia (CNRS Cl.Ferrand, France) J. Wassermann (Univ. München, Germany) J. Robertsson, C. Chapman Schlumberger Research Cambridge, UK T. Braun (INGV Oss. S. Arezzo, Italy) G. Saccorotti (INGV Oss. Vesuviano, Italy) External collaborators
Meetings and research visitsTG Small Scale Subgroup Mushy Seafloor Subgroup Volcanoes Year 2005JanuaryFebruaryAprilAugustSeptemberOctoberNovemberDecember Schlumberger meeting, Cambridge (Marine Seismics meeting) Lokmer (Univ. Dublin) visits INGV Naples EGU General Assembly, Vienna (TG Small scale meeting) Braun (INGV Arezzo) visits Univ. Hamburg Smolenice SPICE R&T Workshop II (TG Small scale meeting) Battaglia (CNRS) visits Univ. Hamburg Saccorotti (INGV Naples) visits Univ. Dublin Lokmer (Univ. Dublin) visits Univ. Hamburg Cesca (Univ. Hamburg) visits INGV Arezzo Sidler (ETHZ Zürich) visits Univ. Hamburg
Research at University of NaplesVolcanoes (TG Small Scale) Develop and apply integrated seismic tools to reconstruct high resolution images of volcanic structures Analysis and modeling of earthquake data Identification and analysis of reflected phases from earthquake seismograms to locate an intra - crustal seismic discontinuity (magma sill) beneath Mt. Vesuvius. Building the 3D tomographic image of the Campi Flegrei (southern Italy) caldera for the optimal location of earthquakes and focal mechanism computation
Research at University of NaplesVolcanoes (TG Small Scale) 3D-CDP Use the whole waveform information (arrival times and amplitudes) to constrain the location, morphology and impedance contrast of interfaces (gas storages, magma chamber top, …) Analysis and modeling of active seismic data Non-linear inversion of 2D reflection data to recontruct the morphology of seismic discontinuities beneath volcanoes 3-D processing, move-out and pre-stack depth migration of seismic sections to identify the main reflectors and characterize their impedance contrast by AVO (Amplitude vs Offset) analyses
Research at University College DublinVolcanoes (TG Small Scale) What role do gas slugs play, in LP event generation?
Research at Univ. HamburgVolcanoes (TG Small Scale) Kilauea, Hawaii Wave propagation in complex 3D media (topography, heterogeneity) by pseudospectral methodInversion techniques to determine time-dependent sourcesApplication to different volcanic events, interpretation of the source mechanism Inverted source Moment tensorcomp. Single Forces
Research at Univ. HamburgMushy Seafloor (TG Small Scale) Experiment setup Study of interface waves propagation at the seafloorWaveform forward modellingWaveform inversionEffects of attenuation, porosity on the excitation of ringing phasesEffect of station coupling and rocking. Fit of observed waveforms
Research at ETH ZürichMushy Seafloor (TG Small Scale) Conventional streamer pp-image Pressure component Horizontal inline component 4C ps-image Vertical component ENHANCEMENT OF FOUR COMPONENT (4C) ACTIVE SEISMIC DATA PROCESSINGDefinition of new methods to extract required a priori information for routine wavefield decomposition of field data. Bouska 2005 Muijs 2004
Research at ETH ZürichMushy Seafloor (TG Small Scale) DETERMINE EFFECTS OF MUSHY SEAFLOOR ON WAVEFIELD DECOMPOSITIONImplication of attenuation on wavefield decompositionCalculation of sea-floor properties Waveform forward modeling for a layered crust including sea-floor mushy layer Sidler
Research at OGS TriesteMushy Seafloor (TG Small Scale) BIOT-TYPE MULTI-PHASE POROELASTIC MODELLING OF FLUID SATURATED MATERIALSThe effects of the sea-floor mushy layer must be consideredfor the correct calculation of sea-floor properties and the related implementation of a forward modelling code.A numerical code has been implemented and will be used in the present analysis. • We developed a Biot-type theory • It covers the whole frequency range. • The frequency effects on the fluid bulk modulus are modeled. • The pressure effects are taken into account (transport properties).
Research at OGS TriesteMushy Seafloor (TG Small Scale) Frozen porous media example Snapshots of the rock-frame vertical velocity at 0.68 s. The grid method is based on the Fourier differential operator and a Runge-Kutta time-integration algorithm. The modeling is second-order accurate in the time discretization and has spectral accuracy in the calculation of the spatial derivatives. Phase velocities of the five modes propagating in partially frozen Berea sandstone versus water proportion: a) η =0 (viscosity) b) η≠0 c) η≠0 (permeabilityκi0=κs0) Dots indicate the velocities at 50% water saturation.
Presentations Mid-Term Review MeetingTG Small Scale 15.15 Cesca, S.,“Source inversion for long period volcanic events”15.20 Battaglia, J., “Seismicity and 3D velocity structure of the Campi Flegrei (Italy)” 15.25 Murphy, S., “Source and propagation effects in micro- earthquake data: application to Campi Flegrei (Italy)”15.30 Lokmer, I., “Towards a better understanding of long- period (LP) signals”15.35 Nguyen, N., “Seismic waves in unconsolidated media”15.40 Sidler, R., “Impact of mushy sea-floor properties on wave-field decomposition of ocean bottom cable data”
SIXTH FRAMEWORK PROGRAMME (FP6) SUSTAINABLE DEVELOPMENT, GLOBAL CHANGE AND ECOSYSTEMS Project in Section: GLOBAL CHANGE AND ECOSYSTEMS Project acronym: VOLUME Project full title: VOLcanoes: Understanding subsurface mass moveMEnt Project Type: SPECIFIC TARGETED RESEARCH PROJECT (STREP) (SPICE is an RTN) Start Date: October 1st, 2005 Duration: 3 years Budget: €3.2 Million www.volume-project.net
Aims of VOLUME: • To better understand sub-surface mass movement, based on surface observations: • Seismicity • Seismic waveforms • Volcano imagery • Gas • Geology • Strain • Large scale deformation (InSar) • Range of different Volcano types at different points in their activity cycles
3. Participant List Partic. Role* Partic. n. Participant name Participant Short name Country Date enter Project** Date exit Project** CO 1 National University Ireland Dublin UCD Ireland 1 36 CR 2 Instituto Nazionale Geofisica Vulcanologia –Osserv. Vesuviano INGV-OV Italy 1 36 CR 3 Universidad de Granada UGR Spain 1 36 CR 4 Universite Joseph Fourier UJF France 1 36 CR 5 Universite de Savoie UdS France 1 36 CR 6 Universidade dos Acores UAC Portugal 1 36 CR 7 Instituto Nazionale Geofisica Vulcanologia- Catania section INGV-CT Italy 1 36 CR 8 Icelandic Meteorological Office IMOR Iceland 1 36 CR 9 Universita’ di Salerno UNISA Italy 1 36 CR 10 Geological and Nuclear Sciences GNS New Zealand 1 36 CR 11 Advanced Computer Systems S.p.a. ACS Italy 1 36 CR 12 Nordic Volcanological Center, University of Iceland NVI Iceland 1 36
Presentations Mid-Term Review MeetingTG Small Scale 15.15 Cesca, S.,“Source inversion for long period volcanic events”15.20 Battaglia, J., “Seismicity and 3D velocity structure of the Campi Flegrei (Italy)” 15.25 Murphy, S., “Source and propagation effects in micro- earthquake data: application to Campi Flegrei (Italy)”15.30 Lokmer, I., “Towards a better understanding of long- period (LP) signals”15.35 Nguyen, N., “Seismic waves in unconsolidated media”15.40 Sidler, R., “Impact of mushy sea-floor properties on wave-field decomposition of ocean bottom cable data”