THE TECTONIC GEOMORPHOLOGY OF THE PHILIPPINE SEA

The Philippine Sea is located at the West Pacific, between two large subduction zones. The sea is surrounded by a deep trench, in which there is little terrigenous import, so the original landscape features are well preserved. According to the exact water depth data, combined with the existing research results, and under the regime of the plate tectonics, this area is divided into four tectonic units, and the main tectonic geomorphology system is studied. The results show that the shape and distribution of topography in the Philippine Sea are controlled by tectonic activity. The west Philippine Sea Basin is characterised by a series of large tectonic geomorphology of NW-SE directions, due to the seafloor spreading of the central rift zone; the east Phiilippine Sea Baisn characterized by a N-S trench-arc-basin system because of the subduction of the Pacific plate. There are some linear ridges and seamounts around the central rift zone, continuous steering ridges in the basin, and echelon rift valleys in the Parece Vela basin. Such a pattern of geomorphology is all related to its special process of formation, corresponding to the complex evolutionary history.