HR: 17:00h
AN: U14A-04    [Abstracts]
TI: An Overview of SEATOS: Sumatra Earthquake and Tsunami Offshore Survey
AU: * Moran, K
EM: kate.moran@gso.uri.edu
AF: University of Rhode Island, Narragansett Bay Campus, Narragansett, RI 02882 United States
AU: Grilli, S
EM: grilli@oce.uri.edu
AF: University of Rhode Island, Narragansett Bay Campus, Narragansett, RI 02882 United States
AU: Tappin, D
EM: drta@bgs.ac.uk
AF: British Geological Survey, Kingsley Dunham Centre Keyworth, Nottingham, NG12 5GG United Kingdom
AB: In May 2005, an international, interdisciplinary team of scientists conducted a detailed survey of the seafloor in the vicinity of the epicenter of the Great Sumatra earthquake of December 26, 2004-dubbed Sumatra Earthquake and Tsunami Offshore Survey (SEATOS 2005). The overall goal of the survey was to gather data to improve models of seafloor displacement and the resulting tsunami waves. To accomplish this goal, SEATOS conducted detailed investigations at seven sites: a large underwater landslide, initially thought to be the result of the December 26th earthquake: a ~20km long trench feature at the deformation front that was interpreted to represent recent seafloor displacement; seafloor locations at three sites on the forearc high; and a steep mound north of Sumatra, interpreted as volcanic. High resolution seismic lines were run across the margin and between detailed study sites to characterize the overall style of the subduction zone (see abstract by Mosher et al., this session). At each site, detailed surveys including seismic, and remotely operated vehicles (ROV) were conducted. ROV surveys included high definition television-quality video imaging of the seafloor, as well as core sampling for biological and geotechnical analyses. During SEATOS, tsunami simulations were also conducted using a wave model based on fully nonlinear Boussinesq equations (see Grilli et al. abstract, this session). Such a model better represents the oscillatory wave trains that were typically observed during the event. Early results suggest seafloor disturbances (from the Dec. 26th 2004 earthquake) and the formation of new seafloor features occurred at the deformation front and stable seafloor conditions prevailed at the forearc high. These data are currently being analyzed, along with recently published seismic inversion analyses, to develop a seafloor displacement model that best represents the Dec. 26th event. Also, the comparison of wave model results with observations at tide gages, one satellite track, and run-up measured in recent field surveys is good.
DE: 3000 MARINE GEOLOGY AND GEOPHYSICS
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 3075 Submarine tectonics and volcanism
SC: Union [U]
MN: Fall Meeting 2005