What is a gravity hole? Indian Ocean mystery that has baffled scientists may have been solved
BENGALURU, KARNATAKA: Scientists from a premier institute in India have finally made a headway discovery about the existence of a 'gravity hole' in the Indian Ocean. A group of researchers from Bengaluru’s Indian Institute of Science claimed that plumes of low-density magma rose from Earth's mantle which led to the formation of the gravity hole.
These plumes originated from the remains of a sunken tectonic plate called Tethys that was lost when India became a part of the Asian subcontinent about 50 million years ago. Mantle plumes, which are abnormally hot rocks within the Earth's mantle, are normally considered to be caused as a result of gravitational anomalies around the Earth. This exhilarating revelation was made by a couple of geophysicists after they conducted the study using computer simulations in the research institute.
What is a 'gravity hole'?
'Gravity hole', officially known as the 'Indian Ocean Geoid Low,' is a region of the ocean where gravity is lower than average. Gravity holes form due to the variation in density and mass distribution as the Earth’s Gravitational Force is not uniform. This means that the water level is around 340 feet lower than the surrounding area.
What did the scientists say?
"Using these simulations we could see this geoid low being non-existent at some point and then taking shape at about 20 million years ago", study author Attreyee Ghosh told Daily Mail. "Such kind of studies would help us address many of the Earth's still unresolved features in the future."
Although the earth is represented as a perfectly round sphere in illustrations and globes, pundits claim it's more like a 'bumpy potato' when it comes to its appearance. "The origin of this geoid low has been enigmatic. Different theories were put forward to explain this negative geoid anomaly," the researchers wrote in their study. Yet "all these studies looked at the present-day anomaly and were not concerned with how this geoid low came into existence."
The blue planet's irregular surface is due to areas of non-uniform gravity stemming from the unequal distribution of matter in its interior. The movement of tectonic plates has further added to the surface deformations that have created mountains and valleys on the Earth's surface. These deformations affect the shape of the oceans as well for the water bodies cover around 70 percent of the planet's surface.
Who discovered the Indian Ocean Geoid Low?
Indian Ocean Geoid Low, found around 700 miles south of the Indian peninsula, was first discovered in 1948 by Dutch geophysicist Felix Andries Vening Meinesz during a ship-based gravity survey. He found the sea level in the region was significantly lower than the global average which hinted at a gravitational anomaly.