Philippine Sea
The Philippine Sea is a marginal sea of the Western Pacific Ocean east of the Philippine archipelago (hence the name), occupying an estimated surface area of 5 million square kilometers (2×106 sq mi). The Philippine Sea Plate forms the floor of the sea. Its western border is the first island chain to the west, comprising the Ryukyu Islands in the northwest and Taiwan in the west. Its southwestern border comprises the Philippine islands of Luzon, Catanduanes, Samar, Leyte and Mindanao.
Its northern border comprises the Japanese islands of Honshu, Shikoku and Kyūshū. Its eastern border is the second island chain to the west, comprising the Bonin Islands and Iwo Jima in the northeast, the Mariana Islands (including Guam, Saipan and Tinian) in the due east, and Halmahera, Palau, Yap and Ulithi (of the Caroline Islands) in the southeast. Its southern border is Indonesia’s Morotai Island.
The sea has a complex and diverse undersea relief. The floor is formed into a structural basin by a series of geologic faults and fracture zones. Island arcs, which are actually extended ridges protruding above the ocean surface due to plate tectonic activity in the area, enclose the Philippine Sea to the north, east and south.
The Philippine archipelago, Ryukyu Islands, and the Marianas are examples. Another prominent feature of the Philippine Sea is the presence of deep sea trenches, among them the Philippine Trench and the Mariana Trench, containing the deepest point on the planet.
The Philippine Sea has the Philippines and Taiwan to the west, Japan to the north, the Marianas to the east and Palau to the south. Adjacent seas include the Celebes Sea which is separated by Mindanao and smaller islands to the south, the South China Sea which is separated by Philippines, and the East China Sea which is separated by the Ryukyu Islands.
The Philippine Sea Plate forms the floor of the Philippine Sea. It subducts under the Philippine Mobile Belt which carries most of the Philippine archipelago and eastern Taiwan. Between the two plates is the Philippine Trench.
