The Indian Ocean geoid low (IOGL), also known as the "gravity hole", is a region in the Indian Ocean where Earth's gravitational pull is weaker than at other parts of the planet. This is caused by a large depression in the seafloor, which is thought to have been created by plumes of magma rising from the Earth's mantle.
The IOGL is about 1.2 million square miles (3 million square kilometers) in size and covers an area just off India's southern tip. The sea level over the IOGL is about 328 feet (100 meters) lower than the global average.
Scientists believe that the IOGL was formed about 140 million years ago when two tectonic plates collided and pushed up a large mountain range. This mountain range eventually collapsed, creating a depression in the seafloor. Over time, magma from the Earth's mantle rose into this depression, creating a low-density region that has a weaker gravitational pull.
The IOGL is a fascinating natural phenomenon that is still being studied by scientists. It is possible that the IOGL could have a role in the formation of earthquakes and tsunamis. It could also be a source of valuable minerals and metals.