Q. With reference to the relief features of Indian Ocean, consider the following statements:

1. The average depth of the Indian Ocean is more in eastern side in comparison to western side
2. The deeps and trenches are almost absent in Indian Ocean

Which among the above is / are correct statements?
Answer: Only 1
Notes: The Indian ocean is smaller than Pacific and Atlantic ocean. It is bounded by Asia in North, Africa in West, Asia in East, Australia in South East and Antarctica in the South. It has got connected with Pacitic and Atlantic oc.ean near Antarctica. The average depth of the ocean is 4000 m. Majority of this ocean is formed by the block mountains of Gondwanaland. Here some prominent marginal seas are Mozambique channal, Red sea, Persian gulf, Andaman sea, Arabian sea, Bay of Bengal etc. The Indian subcontinent in the North divides the Indian ocean into Arabian sea and Bay of Bengal. Johnson has divided the Indian ocean into three zones.

1. The Western zone : It is between the African coast and the mid Indian oceanic ridge, and average depth is around 400 m. or 2000 fathoms in this zone.
2. The Eastern zone : It is deepest with a depth of around 550 m or 3000 fathoms.
3. The Central zone : It represents the mid oceanic ridge where many tiny island are located

Deeps and Trenches : Important deep-Sea trenches are Sunda trench (7450 m deep), o b trench (687.5 m deep). Mauritius trench, Amirante trench etc. The deeps are almost absent.