Indian Ocean gravity hole was caused by extinct ancient sea, scientists say

A rendering of the Earth's gravity as seen by the European Space Agency' Goce satellite. Yellow and orange regions are those with more gravity and the blue, marked over the Indian Ocean, shows where gravity is less pronounced.

Scientists may have finally identified the origins of a deep "gravity hole" in the Indian Ocean — a mysterious region where Earth's gravitational pull is weaker than at other parts of our planet.

The Indian Ocean geoid low (IOGL) is a 1.2 million-square-mile (3 million square kilometers) depression found 746 miles (1,200 kilometers) southwest of India. Compared with its surroundings, the low's gravity is so weak that a layer of its water has been snatched away — making the sea level over the hole 348 feet (106 meters) lower than the global average.