Izu–Bonin–Mariana Arc in the context of "Northeastern Japan Arc"

The Japanese archipelago (Japanese: 日本列島, Hepburn: Nippon/Nihon Rettō; Japanese pronunciation: [ɲip.pon/ɲi.hon ɾeꜜt.toː]) is an archipelago of 14,125 islands that form the country of Japan. It extends over 3,000 km (1,900 mi) from the Sea of Okhotsk in the northeast to the East China and Philippine seas in the southwest along the Pacific coast of the Eurasian continent, and consists of three island arcs from north to south: the Northeastern Japan Arc, the Southwestern Japan Arc, and the Ryukyu Island Arc. The Daitō Islands, the Izu–Bonin–Mariana Arc, and the Kuril Islands neighbor the archipelago.

Japan is the largest island country in East Asia and the fourth-largest island country in the world with 377,975.24 km (145,937.06 sq mi). It has an exclusive economic zone of 4,470,000 km (1,730,000 sq mi).

The Volcano Islands (火山列島, Kazan Rettō), also known as Iwo Islands (硫黄列島, Iō Rettō) are a group of three Japanese islands in the Northwestern Pacific Ocean. They lie southwest of the Ogasawara Islands and are administered as part of the Ogasawara, Tokyo Metropolis. The islands are all active volcanoes lying atop the Izu–Bonin–Mariana Arc that stretches south to the Marianas. They have an area of 32.55 square kilometres (12.57 sq mi), and a population of 380. The island of Iwo Jima in the Volcano Islands lies about 1,240 kilometres (670 nmi; 771 mi) southeast of Miyazaki.

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 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.