The third largest in the world is the Indian Ocean. Its width (between southern Australia and southern Africa) is approximately ten thousand kilometers. The area of the Indian Ocean is 73,556,000 square kilometers (along with the Persian Gulf and the Red Sea).
There are relatively few islands in the water area. The largest include the following: Sri Lanka, Madagascar, Socotra. There are also volcanic islands such as Prince Edward, Mascaren, Crozet and others. On volcanic cones in tropical latitudes, there are coral islands of Chagos, Lakkadivskys, Maldives, Cocos and others.
The Indian Ocean is rich in minerals. So, deposits of gas and oil (especially in the Persian Gulf), monazite sands (in the coastal region in southwestern India) were found on the shelves, gold, phosphorites, and tin ores were found in rock deposits. In rift zones, ores of chromium, manganese, iron, copper, etc. were found. Large deposits of ferromanganese nodules were found in many basins.
The Indian Ocean is entirely located in the eastern hemisphere. Africa is located in the West, Eurasia in the North, Australia and the Sunda Islands in the East, and Antarctica in the South. In the southwest, the Indian Ocean is quite widely connected with the Atlantic, in the southeast - with the Pacific.
The bottom relief is complex and diverse. At the bottom of the Indian Ocean, a system of mid-ocean ridges is distinguished among uplifts. They diverge to the southeast and northwest. Ranges are distinguished by the presence of transverse faults and rifts, seismicity, and underwater volcanism. A large number of deep-sea basins are located between the ridges. The shelf is not very wide, but its size is significant off the Asian coast.
A significant part of the Indian Ocean lies in the subequatorial, equatorial and tropical zones. Its southern part is located in high latitudes to subantarctic. The main feature of the climate in the water area are monsoons - seasonal winds. In this regard, there are only two seasons in the Indian Ocean - quiet, warm and sunny winters and cloudy, hot, rainy and stormy summers. From 10º y. w. south-east trade wind prevails. Temperate latitudes are characterized by a steady and strong wind from the west. The equatorial belt is characterized by a significant amount of precipitation - up to three thousand millimeters per year. In the Persian Gulf, as well as the Red Sea and off the coast of Arabia, by contrast, there is very little rainfall.
The currents of the Indian Ocean in the northern part are formed under the influence of a monsoon change, connecting the system of currents with the seasons. So, summer monsoon (from west to east) and winter monsoon (in the opposite direction) is formed. The southern part is characterized by the Passat South Current and the West Winds.
The average water surface temperature is about seventeen degrees. This relatively low rate is associated with the cooling effect of Antarctic waters. In the northern part, the ocean warms up quite well. Since there is no cold influx, it is the warmest part. In the Persian Gulf in summer, the water temperature can rise to 34 degrees. The southern hemisphere is characterized by a gradual decrease in temperature with increasing latitude.
The organic world in the Indian Ocean is in many ways similar to the Pacific organic world. It is characterized by a variety of species composition of fish. So, for example, the northern part is rich in anchovies, sardinella, tuna, and mackerel. Here you can meet sharks, flying fish and others. The southern waters of the Indian Ocean are populated by nototheniidae, whitefish. Here you can find pinnipeds and cetaceans. The organic world of the coral islands and the shelf is especially rich.