Integrating CRISP IODP drilling and 3D Seismic Study

  Orpheum Room, Grand Hyatt San Francisco
345 Stockton Street, San Francisco, CA
Wednesday, December 7, 2011, 6:00 – 9:30 pm


Conveners: Eli Silver, Paola Vannucchi, Nathan Bangs, Cesar Ranero, Kohtaro Ujiie


During March and April, 2011, IODP Expedition 334 carried out a program of drilling off the southwest coast of Costa Rica, with a focus on understanding the nature of the seismogenic zone and processes of subduction erosion. During April and May of the same year, scientists on the R/V Langseth carried out a 3D seismic reflection acquisition program. The objectives of both scientific programs include a better understanding of the nature and physical properties of rocks above and below the main plate interface, fluid pressures and flow paths along and above the plate interface, and the structural, petrologic, geochemical and and physical property changes that occur across the up-dip end of the seismogenic zone.

IODP Expedition 334 successfully recovered cores to over 500 m depth below sea floor in the upper slope region (Sites U1378 and U1380), nearly 1000 m below sea floor on the outer shelf (Site U1379), and the sedimentary and underlying 70 m of basement rock on the incoming plate. Likewise, the 3D seismic study successfully imaged a region 55 km long by 11 km wide across the shelf and slope to the incoming plate beyond the trench axis. Both the seismic and drilling datasets together can provide powerfully synergistic understanding of the process of seismic initiation and subduction erosion. Because the onboard scientific parties of the drilling leg and the 3D seismic experiment were at sea during the same time period, and also they represent different kinds of expertise, it is critical for us to integrate these datasets at an early stage.

One very timely reason for such integration is that a second CRISP drilling leg is on the schedule for 2012. Secondly, as both the drilling scientists and the 3D seismic group work on interpretation, it will be important for both groups to understand the preliminary findings of the other, as each provides critical information to the same basic problems. Thirdly, we would like to make the initial results of these programs known to broader research community, especially younger researchers.

Workshop Convened by:
Eli Silver, University California, Santa Cruz
Paola Vannucchi, University of Florence, Firenze
Nathan Bangs, University of Texas at Austin
Cesar Ranero, CSI, Barcelona
Kohtaro Ujiie, IFREE, JAMSTEC

6:00     Refreshments and posters
6:45     Introduction to the Mini-Workshop, Agenda | Eli Silver
6:50     Initial basis for the drilling program and reasons for separation of shallow and deep drill sites | Roland von Huene
7:00     Overview of Expedition 334 | Paola Vannucchi
7:20     Overview of 3D seismic program | Nathan Bangs
7:40     Discussion, possible set of 5 minute presentations
8:10     Second CRISP Expedition | Harris
8:25     Discussion of priorities for the new drill sites, ties to 3D seismic results, and closing statements
9:00     Adjourn