This proposal requests funds to permit Dr. Yehuda Bock, Scripps Institution of Oceanography, University of California, San Diego, to pursue with Dr. Jacub Rais, Indonesian National Coordination Agency for Surveys and Mapping (BAKOSURTANAL), for 24 months, a study of the tectonics of the Indonesian archipelago, using measurements of the Global Positioning System (GPS). 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 of this project is 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 in eastern Indonesia. In the Indonesian region, many tectonic processes that result in mountain building, continental accretion, destruction of continents, displacement of ophiolites, development of subduction zones, arc polarity reversal, basin closure, etc. are now active. This project will provide U.S. scientists a unique opportunity to observe such phenomena. Because Indonesia lies in a zone of high seismicity and volcanic activity, monitoring of crustal deformations has potential humanitarian and economic value as well. The U.S. and Indonesian collaborators are highly respected scientists who have records of successful research in the field of this project. The present project will allow the collaborators to combine their talents and interests for mutual benefit. This project is relevant to the objectives of the Science in Developing Countries Program which seeks to increase the level of cooperation between U.S. scientists and engineers and their counterparts in developing countries through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit. Primary support for this project is provided by NSF Grant No. EAR8817067, the Indonesian government, and the World Bank.
