Java and Bali to the east. Borneo lies to the north and Christmas Island is to the south. It is the world's 13th largest island. Java is surrounded by the Java Sea to the north, Sunda Strait to the west, the Indian Ocean to the south and Bali Strait and Madura Strait in the east. Java is almost entirely of volcanic origin; it contains thirty-eight mountains forming an east–west spine that have at one time or another been active volcanoes. The highest volcano in Java is Mount Semeru (). The most active volcano in Java and also in Indonesia is Mount
Kuril–Kamchatka Trench Kuril–Kamchatka Trench The Kuril–Kamchatka Trench or Kuril Trench (, "Kurilo-Kamchatskii Zhyolob") is an oceanic trench in the northwest Pacific Ocean. It lies off the southeast coast of Kamchatka and parallels the Kuril Island chain to meet the Japan Trench east of Hokkaido. It extends from a triple junction with the Ulakhan Fault and the Aleutian Trench near the Commander Islands, Russia, in the northeast, to the intersection with the Japan Trench in the southwest. The trench formed as a result of the subduction zone, which formed in the late Cretaceous, that created the Kuril island arc as well as the