The Andaman Sea is a body of water to the southeast of the Bay of Bengal, south of Myanmar, west of Thailand and east of the Andaman Islands. It is part of the Indian Ocean. It is roughly 1200 kilometres long (north-south) and 650 kilometres wide (east-west), with an area of 797,700 km². Its average depth is 870 metres and the maximum depth is 3,777 metres.
The Andaman Sea narrows in its south eastern region to form the Straits of Malacca, which separate the Malay Peninsula from the island of Sumatra.
Running along a north-south line on the seabed of the Andaman Sea is the boundary between two tectonic plates, the Burma plate and the Sunda Plate. These plates (or micro plates) are believed to have formerly been part of the larger Eurasian Plate, but were formed when transform fault activity intensified as the Indian Plate began its substantive collision with the Eurasian continent.
As a result, a sea floor spreading centre was created, which began to form the marginal basin which would become the Andaman Sea, the current stages of which commenced approximately 3 - 4 million years ago.
Within the sea to the east of the main Great Andaman island group is Barren Island, an active volcano (the only presently active volcano associated with the Indian subcontinent). Its volcanic activity is due to the ongoing subduction of the India Plate beneath the Andaman island arc, which forces magma to rise in this location of the Burma Plate. The volcanic island of Narcondam which lies further to the north was also formed by this process; however it has not recently been active.
The Andaman Islands are a group of islands in the Bay of Bengal, and are part of the Andaman and Nicobar Islands Union Territory of India. There are 576 islands in the group, 26 of which are inhabited. They are located 950km from the mouth of the Hooghly River, 193 km from Cape Negrais in Myanmar (the nearest point of the mainland), and 547 km from the northern extremity of Sumatra. The length of the island chain is 352 km and its greatest width is 51 km. The total land area of the Andamans is 6408 km².
The climate is typical of tropical islands of similar latitude. It is always warm, but with sea-breezes. Rainfall is irregular, but usually dry during the north-east, and very wet during the south-west, monsoons.
