18 Feb 2022.

Introduction:

Recently, researchers traced the tectonic evolution of “Greater Maldive Ridge (GMR)” which is a geodynamic feature in western Indian Ocean.

Highlights:

• The tectonic evolution can help in reconstruct the original Gondwanaland fracture.
• This feature led to present-day configuration of continents, continental fragments, as well as formation of ocean basins in the Indian Ocean.

Key Findings of the team:

• The team found that, Maldive Ridge might have formed in close vicinity of Mid-Oceanic Ridge, where new ocean floor is created due to divergent motion of spreading centre or lithospheric plates.
• They also concluded that, Deep-Sea Channel region (DSC) may probably be oceanic in nature, because of presence of underplated materials associated with hotspot volcanism.
•  Researchers chalked possible geological cross-sections along the GMR, with the help of high-resolution gravity data derived from satellite.

Three-dimensional picture along GMR

Research team used gravity anomalies to form a three-dimensional picture of variation along the Greater Maldive Ridge and adjoining ocean basins.

State of Gravitational Equilibrium

• Study provides the crustal architecture as well as the state of gravitational equilibrium between Earth’s crust and mantle of the GMR segment of larger Chagos-Laccadive Ridge (CLR) system.
•  It was found that, Moho is deeper across Maldive Ridge (MR) segment and shallows southwards in Deep-Sea Channel region (DSC).
• However, effective elastic thickness values were lower over MR compared in DSC region.

About Maldive Ridge

• The Maldive Ridge is located in the western Indian Ocean, southwest of India. It is aseismic, that is not associated with earthquake activities. The ridge largely remains uninvestigated.
• It is of most importance to gain knowledge on structure and geodynamics of such structures. It is a submarine ridge, extends from western shore of Hindustan Peninsula to Arabian-Indian Ridge.
•  It is about 3000 km in length, 200-450 km in width and have the elevation of 2-5 km.
• Peaks of this ridge rise above the water, to form coral islands (atolls) namely, the Laccadive Islands, Chagos Archipelago and Maldive Islands.