The massive “gravity hole” in the Indian Ocean, spanning over three million square kilometres, has been explained by a group of Indian scientists.
New Delhi, July 3: The massive “gravity hole” in the Indian Ocean, spanning over three million square kilometres, has been explained by a group of Indian scientists. The Indian Ocean Geoid Low (IOGL) is the most noticeable gravitational anomaly on Earth, with a sea level 106 metres below the average of all other places on the planet.
A mass deficiency in the Earth’s mantle under the Indian Ocean is responsible for the IOGL, according to research published in Geophysical Research Letters.
The Bangalore-based Indian Institute of Science (IISc) used computer simulations and a reconstruction of plate tectonic movements over the last 140 million years to determine where the “gravity hole” originated.
Some tectonic plate fragments were discovered to have broken through the mantle under Africa, causing plumes to emerge from the depths of the Indian Ocean.
Sinking Tethyan slabs “perturbed the African Large Low Shear Velocity Province and generated plumes beneath the Indian Ocean,” the study’s authors explained, explaining the origin of the negative geoid anomaly.
They elaborated on how the IOGL’s location and form may have been influenced by a series of interactions between processes occurring at depth in the Indian Ocean.
“These plumes, along with the mantle structure in the vicinity of the geoid low, are responsible for the formation of this negative geoid anomaly,” the study’s main authors, Debanjan Pal and Attreyee Ghosh of the IISc, said.
About 20 million years ago, as the plumes began to spread inside the upper mantle, the IOGL probably obtained its current configuration, as determined by the scientists. And it will likely persist for as long as mantle material is being transported.
According to a remark from Pal in Scientific American, “when the temperature anomalies causing this low geoid shift out of the present-day location, the geoid low will start to dissipate.”
