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?