The objective of the research is to resolve several major problems related to the active tectonics of the Philippine Sea Plate and its boundaries, specifically, the following topics: (1) determination of accurate Philippine Sea - Eurasian Plate and Philippine Sea-Pacific poles and rotation rates; (2) the magnitude of plate driving forces at trench boundaries; (3) the mechanism of back-arc spreading; (4) the mechanism of strike-slip in the forearc; (5) the mechanics of arc-continent collision; and (6) the distribution of deformation and seismic hazard in southeast Japan. The procedure is to collect and analyze GPS measurements as sites strategically placed along the eastern, western and northern boundaries of the Philippine Sea Plate in southeast Japan, and in the Bonins, Marianas and Micronesia. The information provided by the GPS measurements will test hypotheses that have been proposed to explain a variety of tectonic processes, prime examples of which are found in the Philippine Sea Plate and its boundaries. These results will be integrated with those from ongoing seismic and tectonic investigations of the area.
