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
Tongue of the Ocean peripheral shelter isolating it from ocean disturbances, particularly high ambient noise. This channel and the Providence Channel are the two main branches of the Great Bahama Canyon, a submerged geological feature formed by erosion during periods of lower sea level. During their early history the Tongue of the Ocean and the Providence Channels were broad, relatively shallow basins flanked by growing carbonate banks. As the Blake-Bahama platform subsided, sedimentation kept pace with subsidence on the banks, but not in the basins. Tongue of the Ocean The Tongue of the Ocean (TOTO) is the name of a deep oceanic trench in