Scientists have solved the mystery of the gravitational "hole" in the Indian Ocean

Scientists have puzzled over the origin of the gravitational "hole" in the Indian Ocean for decades. Now they believe that they have finally found the answer: it was formed due to another anomaly - the "African drop". Study this was published in Geophysical Research Letters.

This is the so-called Indian Ocean Geoid Low (IOGL), which was first discovered in 1948. It is located 1,200 kilometers southwest of the coast of India and covers an area of ​​about 3 million square kilometers. The force of gravity in it is considered abnormally low, as a result of which the sea level above the depression is 106 meters below the world average.

To determine the cause of this strange circumstance, the authors of the study created 19 computer models of how the region formed over the past 140 million years. As it turned out, the abyss was formed due to the characteristic structure of the mantle in combination with the adjacent anomaly under Africa, referred to as the African Large Low Shear Province (LLSVP) or "African drop."

The scientists concluded that the “African drop” was the root cause of the formation of IOGL. It also occurred as a result of the movement of the sunken Tethyan plates, which, most likely, are the remains of the bottom of the ancient Tethys ocean. About 200 million years ago, it washed the continents of Laurasia and Gondwana.

Both Africa and India were once part of Gondwana, but India later moved north into the Tethys Ocean. After it sank, the Indian Ocean was formed. It happened about 120 million years ago.

IOGL took on its current form approximately 20 million years ago when plumes began to spread in the upper part of the mantle. As soon as these flows dry up, the abyss will also disappear, the researchers are sure. But this will happen only after a few million years.