Bonin Islands Pacific Plate is subducting under the Philippine Sea Plate, which creates an oceanic trench to the east of the islands: the Bonin Trench. The crust of the Ogasawara Islands was formed by volcanic activity when subduction began 45–50 million years ago, and is composed mostly of an andesitic volcanic rock called boninite, which is rich in magnesium oxide, chromium, and silicon dioxide. The Ogasawara Islands may represent the exposed parts of an ophiolite that has not yet been emplaced on oceanic crust. The rocks of the Volcano Islands are much younger; Iwo Jima is a dormant volcano characterized by rapid
Japanese occupation of the Andaman Islands the Indian Independence League. Notionally this government continued to administer the islands, which were almost the only territory it ever acquired, until the British retook them in 1945, but in practice little had changed. As food became scarcer in 1945, the Japanese resorted to ever more desperate measures. Between 250 and 700 people (estimates vary) from the Aberdeen area of South Andaman were deported to an uninhabited island to grow food. According to a survivor, a released convict called Saudagar Ali, at least half drowned or were eaten by sharks as they were pushed out of boats in the dark,