Mid-oceanic ridge divides the floor of Indian ocean in East-west portion. Deep trenches are also present in it.
Indian Ocean, body of salt water covering approximately one-fifth of the total ocean area of the world. It is the smallest, geologically youngest, and physically most complex of the world’s three major oceans. It stretches for more than 6,200 miles (10,000 km) between the southern tips of Africa and Australia and, without its marginal seas, has an area of about 28,360,000 square miles (73,440,000 square km). The Indian Ocean’s average depth is 12,990 feet (3,960 metres), and its deepest point, in the Sunda Deep of the Java Trench off the southern coast of the island of Java (Indonesia), is 24,442 feet (7,450 metres).
The Indian Ocean is bounded by Iran, Pakistan, India, and Bangladesh to the north; the Malay Peninsula, the Sunda Islands of Indonesia, and Australia to the east; Antarctica to the south; and Africa and the Arabian Peninsula to the west. In the southwest it joins the Atlantic Ocean south of the southern tip of Africa, and to the east and southeast its waters mingle with those of theThe question of defining the oceanic limits of the Indian Ocean is complicated and remains unsettled. The clearest border and the one most generally agreed upon is that with the Atlantic Ocean, which runs from Cape Agulhas, at the southern tip of Africa, due south along the 20° E meridian to the shores of Antarctica. The border with the Pacific Ocean to the southeast is usually drawn from South East Cape on the island of Tasmania south along the 147° E meridian to Antarctica. Bass Strait, between Tasmania and Australia, is considered by some to be part of the Indian Ocean and by others to be part of the Pacific. The northeastern border is the most difficult to define. The one most generally agreed upon runs northwest from Cape Londonderry in Australia across the Timor Sea, along the southern shores of the Lesser Sunda Islands and of Java, and then across the Sunda Strait to the shores of the island of Sumatra. Between Sumatra and the Malay Peninsula the boundary is usually drawn across the Singapore Strait. Pacific Ocean.