Gravitational anomalies on Earth have always attracted the attention of scientists. One of the deepest and most mysterious anomalies is under the Indian Ocean, where the gravitational pull weakens to a very low level, creating a massive gravitational “hole”. But what causes this relative weakening has long been a mystery.
Recently, two researchers at the Indian Institute of Science proposed a new hypothesis about the origin of this gravitational anomaly. They believe the answer lies more than 1,000 kilometers below the Earth’s crust, where about 30 million years ago the cold, dense remains of an ancient ocean plunged into the “graveyard of plates” under Africa, causing a disturbance in the molten rock.
Researchers used computer models to recreate the movement of Earth’s tectonic plates and mantle over the past 140 million years. They found that all of the models that replicated the gravity trough beneath the Indian Ocean had one thing in common: plumes of hot, low-density magma rising from beneath the trough. These plumes, combined with features of the mantle structure, created a lowering of the geoid.
However, despite the interesting results of the study, scientists note that more data are needed to finally resolve the debate over the origin of the gravity anomaly. In 2018, a team of scientists from the Indian National Center for Polar and Ocean Research began deploying seismometers in the deformation zone beneath the Indian Ocean to obtain additional data on the area.
Nevertheless, the new hypothesis opens new perspectives for studying gravitational anomalies on Earth and understanding the processes occurring in its interior. Research in this area can lead to new discoveries and expand our knowledge of the planet we live on.
