The PIs will conduct a five-year study using measurements to the Global Positioning System (GPS) of the tectonics of the Indonesian archipelago. In the first year they will study deformation associated with oblique plate convergence in Sumatra. Specifically, they will examine the mechanism of decoupling of the oblique slip into normal subduction and shear slip on faults parallel to the convergent margin, by measuring the deformation both southwest and northeast of the Sumatran fault zone. The long-range goal is to extend GPS measurements across the entire Indonesian archipelago, concentrating on specific tectonic problems such as the distribution and rates of slip associated with arc-continent collision in the Banda arc. GPS is the only available technique that will provide information on the rate of subduction of the Australian continental lithosphere at the Timor trench. The PIs will begin transfer of GPS technology to Indonesia under a cooperative arrangement between U.S. and Indonesian scientists sponsored by the National Science Foundation, the Indonesian government, and the World Bank.
