This award supports a two-year cooperative research project between Professor John Hildebrand, Scripps Institution of Oceanography, University of California, San Diego, and Professor Junzo Kasahara, Earthquake Research Institute, University of Tokyo. The project involves placing seismic stations in island sites along the Mariana, Yap and Palau Trench regions of the western Pacific, in coordination with a program for long-term instrumenting abandoned telecommunications cables in the western Pacific with seismic and magnetic sensors. A graduate student from UC San Diego will conduct research at the University of Tokyo as part of this project. The oceanic deep-sea trenches of the western Pacific are the result of large-scale subduction of oceanic crust in this region. Associated with subduction is the generation of high levels of seismicity along dipping Benioff zones on the landward side of the oceanic trenches. The large magnitude earthquakes generated at western Pacific subduction zones has been extensively studies using the Global Seismic Network, providing a detailed mapping of the configuration and characteristics of the seismogenic zone. Smaller magnitude earthquakes require regional seismic networks for study. This has particularly been accomplished on the Japanese Islands where an exensive regional netowrk of seismic stations are positioned above the seismogenic zone. Other subduction zone regions of the western Pacific have fewer island sites available for placement of seismic stations, yet these areas are important to gain a complete picture of the seismicity and tectonic behavior of the western Pacific.
