There is a 'gravity hole' in the Indian Ocean, scientists now know why (2023)

Scientists have identified a "gravity hole" in the Indian Ocean, where Earth's gravitational pull is weaker and sea levels dip by over 328 feet (100 meters). This anomaly, first discovered in 1948, has been linked to plumes of magma originating from deep within the Earth. Researchers from the Indian Institute of Science in Bengaluru conducted simulations using supercomputers to explore the geological history of the area, dating back 140 million years. Their study, published in Geophysical Research Letters, suggests that the gravity hole, or Indian Ocean geoid low, formed due to the disappearance of an ancient ocean as the Indian landmass drifted northward and collided with Asia. The simulations indicated that the presence of magma plumes was crucial for the formation of the gravity hole, as they brought low-density material closer to the surface. The geoid low is the largest gravitational anomaly on Earth, covering approximately 1.2 million square miles (3 million square kilometers). While the study provides a plausible explanation for the gravity hole, some experts have pointed out limitations in the modeling approach and discrepancies between predicted and actual geoid shapes. The future of the geoid low remains uncertain, depending on tectonic plate movements and mass anomalies within the Earth. Overall, the research offers new insights into the complex geological processes that shape our planet.