Previous Year Question

The 90° East Ridge or Ninetyeast Ridge is an extremely long submarine ridge located on the floor of the Indian Ocean. It derives its name from the fact that much of its length runs approximately parallel to 90° east longitude.

The ridge extends southward from beneath the Bay of Bengal for nearly 5,000 km and reaches close to the Southeast Indian Ridge. Its northern part is buried beneath the very thick sediments of the Bengal Fan.

It is not a presently active mid-ocean spreading ridge but a major aseismic volcanic ridge. Its formation is associated with the northward movement of the Indian Plate and prolonged volcanic activity.

The 90° East Ridge is an important relief feature of the Indian Ocean floor and also helps form geographical boundaries between several deep-sea basins of the eastern and western Indian Ocean.