Greater Maldive Ridge(GMR)

In news– In a recent study, an Indian researcher traced the tectonic evolution and the nature of the Greater Maldive Ridge (GMR) , a very crucial geodynamic feature in the western Indian Ocean whose origin has been the centre of many scientific debates.

About the study-

The study was conducted by the Indian Institute of Geomagnetism, Mumbai, an autonomous institute of the Department of Science & Technology, Govt. of India.
The study has chalked the possible geological cross-sections along the GMR for the first time with the help of satellite-derived high-resolution gravity data.
The researchers postulated that the GMR may be underlain by an oceanic crust.
The results from their study can provide additional constraints in understanding the plate-tectonic evolution of the Indian Ocean.
The study can help reconstruct the original Gondwanaland break up and dispersal that led to present-day configuration of continents, continental fragments, and formation of ocean basins in the Indian Ocean.
It provides the crustal architecture and the state of gravitational equilibrium between Earth’s crust and mantle (isostasy) of the Greater Maldive Ridge segment of the larger Chagos-Laccadive Ridge (CLR) system.
The study, based mainly on the interpretation of gravity anomalies (small differences in the pull of gravity) with broadband seismic and refraction seismic data, provided for the first time a three-dimensional picture of the variation of Moho along the Greater Maldive Ridge and the adjoining ocean basins.
IIG team found that Moho is deeper over the Maldive Ridge (MR) segment and shallows southwards in the Deep Sea Channel region (DSC).
However, the effective elastic thickness (a proxy for the strength of the lithosphere) values were lower over the MR compared to the DSC region.
The research suggests that Maldive Ridge might have formed in the close vicinity of the Mid-Oceanic Ridge (where creation of a new ocean floor occurs due to divergent motion of lithospheric plates or spreading centre).

About Maldive Ridge–

It is an aseismic ridge that is not associated with earthquake activities.
It is located in the western Indian Ocean, southwest of India, which is not well investigated.
It is of paramount importance to gain knowledge on the structure and geodynamics of aseismic ridges (as it provides valuable inputs towards understanding the evolution of ocean basins).
It extends from the western shore of the Indian Peninsula to the Arabian-Indian (or Carlsberg) Ridge.
The peaks of the Maldive Ridge rise above the water, forming coral islands (atolls)—the Laccadive Islands, Maldive Islands, and Chagos Archipelago.

What is Mohorovicic discontinuity (Moho)?

The Mohorovičić discontinuity, usually referred to as the Moho discontinuity or the Moho, is the boundary between the Earth’s crust and the mantle.
It is defined by the distinct change in velocity of seismological waves as they pass through changing densities of rock.