Izu–Ogasawara Trench in the context of "Philippine Sea plate"

The Philippine Sea plate or the Philippine plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines. Most segments of the Philippines, including northern Luzon, are part of the Philippine Mobile Belt, which is geologically and tectonically separate from the Philippine Sea plate.

The plate is bordered mostly by convergent boundaries: To the north, the Philippine Sea plate meets the Okhotsk microplate at the Nankai Trough. The Philippine Sea plate, the Amurian plate, and the Okhotsk plate meet near Mount Fuji in Japan. The thickened crust of the Izu–Bonin–Mariana arc colliding with Japan constitutes the Izu Collision Zone. The east of the plate includes the Izu–Ogasawara (Bonin) and the Mariana Islands, forming the Izu–Bonin–Mariana Arc system. There is also a divergent boundary between the Philippine Sea plate and the small Mariana plate which carries the Mariana Islands. To the east, the Pacific plate subducts beneath the Philippine Sea plate at the Izu–Ogasawara Trench. To the south, the Philippine Sea plate is bounded by the Caroline plate and Bird's Head plate. To the west, the Philippine Sea plate subducts under the Philippine Mobile Belt at the Philippine Trench and the East Luzon Trench. (The adjacent rendition of Prof. Peter Bird's map is inaccurate in this respect.) To the northwest, the Philippine Sea plate meets Taiwan and the Nansei islands on the Okinawa plate, and southern Japan on the Amurian plate.It also meets the Yangtze plate due northwest.

The Japan Trench is an oceanic trench part of the Pacific Ring of Fire off northeast Japan. It extends from the Kuril Islands to the northern end of the Izu Islands, and is 8,046 metres (26,398 ft) at its deepest. It links the Kuril–Kamchatka Trench to the north and the Izu–Ogasawara Trench to its south with a length of 800 kilometres (497 mi). This trench is created as the oceanic Pacific plate subducts beneath the continental Okhotsk microplate (a microplate formerly a part of the North American plate). The subduction process causes bending of the down going plate, creating a deep trench. Continuing movement on the subduction zone associated with the Japan Trench is one of the main causes of tsunamis and earthquakes in northern Japan, including the megathrust Tōhoku earthquake and resulting tsunami that occurred on 11 March 2011. The rate of subduction associated with the Japan Trench has been recorded at about 7.9–9.2 centimetres (3.1–3.6 in)/yr.

The Mariana plate is a micro tectonic plate located west of the Mariana Trench which forms the basement of the Mariana Islands which form part of the Izu–Bonin–Mariana Arc. It is separated from the Philippine Sea plate to the west by a divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific plate to the east is a subduction zone with the Pacific plate subducting beneath the Mariana. This eastern subduction is divided into the Mariana Trench, which forms the southeastern boundary, and the Izu–Ogasawara Trench the northeastern boundary. The subduction plate motion is responsible for the shape of the Mariana plate and back arc.