RAPID: Deep seismic investigation of Sumatran subduction zone seismic gap

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This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This is a RAPID project that sends an early career female researcher to participate in a unique, state-of-the-art, 3D seismic study of the central portion of the Mentawai segment of the Sumatran subduction zone to collect and interpret detailed geophysical data of the Sumatran subducting slab down to a depth of several tens of kilometers. Three transects each ~350-400km in length will be surveyed. The 21 day survey will be carried out on an industry vessel with outstanding acquisition capabilities, including an ultra-long streamer (15km), the longest ever used, and will provide new constraints on the structure of the Sumatran margin, including imaging of the megathrust fault plane from its shallowest expression at the trench to the downdip limit of the locked zone. Data will also be used to image other active and possibly tsunami prone faults in the area. Resulting data will be used to examine the rupture surface of past and future earthquakes and other deep interfaces using a novel technique exploiting the wavefield recorded at large source-receiver distances. Goals are to link structural information with studies of tectonic vertical movements on the Mentawai Islands to yield a breakthrough in our understanding of subduction zone processes. Broader impacts of the work include elucidation of earthquake and seismogenically-gernearted tsunami hazards in the Sumatran area which has highly populated coastal cities.