NEAREST Kick Off Meeting
Bologna, 09/10/2006
WP2WP2Tsunami source Tsunami source characterisationcharacterisation
OBJECTIVES
Collect wide-angle seismic profiles across the continental margin and basins offshore SW Iberia to obtain 2-D velocity models and constrain the geometry of the main boundaries. Integration of existing MCS depth images and WAS velocity models must allow to:
1) Map the deep crustal and upper mantle structure, so that geodynamic models of the area can be tested;
2) Determine the location and crustal-scale geometry of the main fault surfaces accommodating plate convergence;
3) Construct coarse 3-D velocity models to be used to relocate local seismicity recorded in WP3;
4) Constrain physical properties () to characterise the main structural domains and tectonic features.
TASKS
Task 2.1 Reprocessing and pre-stack depth migration of existing MCS dataParticipating: CSIC/ICREA, ISMAR ,UBO
Task 2.2 Wide-Angle reflection/refraction acquisition experimentParticipating: CSIC, ISMAR ,UBO, CNRST, INGV, AWI, FFCUL
Task 2.3 Processing and modelling of acquired wide-angle seismic dataParticipating: CSIC ,UBO, AWI, FFCUL
1 Pre-doc student (36 months)
Task 2.1 Reprocessing and pre-stack depth migration of existing MCS data
What profiles are worth to be depth-migrated? What are the criteria to select them?
Task 2.2 Wide-Angle reflection/refraction acquisition experiment
CSIC request for ~30 days shiptime with BIO Hesperides (WAS only)
Profile 1: 295 km, Horseshoe Abyssal plain to accretionary wedge. To characterize E-W dipping subduction zone underthe Gibraltar arc
Profile 2: 305 km, Iberian to the Moroccan margin. To constrain 3-D geometry of plate boundary, lineament of Portimao-Guadalq. Banks, nature and variability of the crust under the prism
Profile 3: 275 km, NE limit of Gorringe Bank to E Coral Patch Ridge To characterize deep structure of Marques de Pombal and Horseshoe fault system
~25-30 OBS/H each profile > LSF IFM-GEOMAR + CSIC, UBO-Ifremer, FFCUL?
Task 2.2 Wide-Angle reflection/refraction acquisition experiment
BB AWI-OBS network location?
Shot over the BB AWI-OBS network that will be deployed as part of WP3:
• Network location and consequent airgun shot locations to be defined
• Ship schedules to be defined and coordinated (09/2007 difficult for Hesperides)
Task 2.3 Processing and modelling of acquired wide-angle seismic data
• Data pre-processing, phase picking
• 2-D refraction/reflection travel-time inversion along profiles (velocity, reflector’s geometry)
• Estimation of model parameters uncertainty > Monte-Carlo type
• Construction of a 3-D block using 2-D profiles
• 3-D first arrival inversion at the BB AWI-OBS network sub-region > to be used joint inversion of local earthkaques location
SUB-TASKS
WP2 DELIVERABLES
D4 - Reprocessing of existing MCS dataD5 - Cruise for reflection/refraction experiment at seaD6 - Processing of wide-angle seismic data
WP2 MILESTONES
M2 – End of the processing of reflection/refraction data, end of experiments at sea
• Proposal for funding and shiptime with Hesperides(?) submitted to Spanish Agency (Acciones Complementarias to EU Projects) in July 20th 2006
• Max. Budget is 25% of EU contribution to CSIC
• Response expected by the end of this year
ACTIONS MADE TO DATE
NEAREST-SEIS (WP2)NEAREST-SEIS (WP2)
29 days shiptime
Dates: 09/2007 – 09/2008
MCS + WAS + Multibeam + Potential fields
NEAREST-CORE (WP6)NEAREST-CORE (WP6)
21 days shiptime
Dates: 09/2007 – 09/2008
Coring + HRS + Multibeam + Heat flux
NEAREST-SEISNEAREST-SEIS
• 7 days MCS
• 20 days WAS
Port call in Cadiz between the 2 legs
PROPOSED SCHEDULE AND POTENTIAL ISSUES
WP2 Objectives & Tasks Accomplishment
Pre-doc (asap!)
MCS > OK WAS? > Survey!
Approval (12/2006)
Available shiptime slot?OBS/H
Hespérides > not before 11/2008!
Sarmiento de Gamboa > operative by 01/2008(?)
LSF-GEOMAR once shiptime allocated
CSIC funding for 10-15 requested in 08/2006
Other OBS?