Geomorphology of the Philippine Sea floor

Abstract

Morphology of the three main depressions of the Philippine Sea floor is discussed. Special attention is paid to comparative characteristic of fault zones which most specialists believe to be of spreading type. Structural prolongation of the Jap trough northward is proved to be the fault Jap and submarine mountain chain Kienan. In the 17th voyage of the «Dmitry Mendeleev» vessel a survey of the southern part of the fault zone was carried on, the maximum depth measured being 6900 m. The central fault of the Philippine basin is proved not to exceed the bounds of the depression and not, to reach the Taiwan Island as it was thought before. The sea floor topography near the junction of the Jap and Mariana troughs represent a system of fan-like depressions and ridges, the maximum depth being 8000 m. Bathymetric map of the sea was verified and a geomorphological map has been compiled.