Indian Ocean Geoid Low

The Indian Ocean Geoid Low (IOGL) is a gravity anomaly in the Indian Ocean. A circular geoid low situated just south of the Indian peninsula, it is the region with Earth's largest gravity anomaly. It forms a depression in the sea level covering an area of about 3 million km² (1.2 million sq mi), almost the size of India itself. Discovered in 1948 by Dutch geophysicist Felix Andries Vening Meinesz as a result of a ship's gravity survey, it remained largely a mystery until May 2023, when the weak local gravity was empirically explained using computer simulations and seismic data.