BENGALURU: A researcher from the Indian Institute of Science (IISc), Bengaluru and others from the GFZ German Research Centre for Geosciences, Germany, have made a beakthrough study in the field of earth sciences that can help scientists better understand what happens inside the earth's crust, something we know very less about.
The study is related to the the geoid formation (shape taken by oceans surfaces under the influence of only the earth's gravity and rotation) found just south of the Indian peninsula. “The existence of the Indian Ocean geoid low is one of the most outstanding problems in Earth Sciences. It is the lowest gravity anomaly on earth and so far no consensus existed regarding its source” says Prof Attreyee Ghosh, an Assistant Professor at the Centre for Earth Sciences, IISc.
Several studies in the past have tried to explain this phenomena. "There has been no convincing explanation of the source of this phonemena until now," says a release from the institute.
The Indian Ocean Geoid Low (IOGL) as it has been called spans a vast extent south of the Indian subcontinent, and is dominated by a significant low of minus 106 metres, south of Sri Lanka. “It is remarkable as there is some mass deficit in the deep mantle of the region that's causing the low," adds Ghosh.
In their study, the researchers have used numerical models based on a type of movement caused within a fluid where hotter and lighter materials rise to the top and cooler and denser material sinks under the influence of gravity.
Seismic topography models have also been used to obtain a three dimensional picture of the earth’s interior. The study was successful in convincingly showing that lighter material in the upper to mid mantle below the IOGL seem to be responsible for the existence of the gravity low in this region.