Context: A study by National Centre for Polar and Ocean Research (NCPOR) revealed that some basaltic samples in Ninety East Ridge were highly alkaline and had very similar compositions to those released by the Kerguelen hotspot in the Southern Indian Ocean.

About the Study

• A recent study has brought new insights into the critical processes involved in the movement of the earth’s tectonic plates.

• A team of scientists at the National Centre for Polar and Ocean Research (NCPOR) studied samples of igneous rocks collected near the Ninety East Ridge in the Indian Ocean.

• NCPOR is an autonomous body under the Ministry of Earth Science.

• Ninety East Ridge is an aseismic ridge located almost parallel to 90 degrees east longitude in the Indian Ocean.

• This expedition was run under International Ocean Discovery Program (IODP).

Key highlights of the study

• Some basaltic samples were highly alkaline and had very similar compositions to those released by the Kerguelen hotspot in the Southern Indian Ocean.

• The minimum age of the alkaline samples was 58 million years, much younger than the adjacent oceanic crust surrounding Ninety East Ridge, which is around 82-78 million years old.

• The Indian tectonic plate was contemporaneously moving northward at a very high speed.

• A conclusion can be drawn that it had dragged a considerable amount of Kerguelen plume material for more than 2,000 km underneath the Indian lithosphere.

Kerguelen hotspot

• The Kerguelen hotspot is a volcanic hotspot at the Kerguelen Plateau in the Southern Indian Ocean.

• The Kerguelen hotspot has produced basaltic lava for about 130 million years.

• The Kerguelen Islands, an archipelago in the southern Indian Ocean.

• Administratively a part of the French Southern and Antarctic Lands, it consists of the island of Kerguelen (also known as Desolation Island) and nearly 300 islets, which together cover about 2,400 square miles.

• Heavily glaciated Kerguelen Island, about 100 miles in length, has active glaciers and peaks up to 6,445 feet.

About IODP

• The IODP is an international marine research collaboration.

• Aim: To advance scientific understanding of the Earth through drilling, coring, and monitoring the subseafloor.

• The science plan covers a 10-year period of operations.

It consists of a list of scientific challenges organized into four themes-

• Climate and Ocean Change

• Biosphere Frontiers

• Earth Connections

• Earth in Motion

They are funded by the USA, Japan, the EU, China, Korea, Australia, New Zealand, Brazil and of course India (Ministry of Earth Science).

What are tectonic plates?

• A tectonic plate is a massive, irregularly-shaped slab of solid rock, generally composed of both continental and oceanic lithosphere.

• It is also called a lithospheric plate.

• A tectonic plate may be a continental plate or an oceanic plate - classified based on which of the two occupies the larger portion of the plate.

• The Indian tectonic plate includes Peninsular India and the Australian continental portions.