Produced by: Mohsin Shaikh
The Indian Ocean "gravity hole" is Earth's deepest geoid low. Its weak gravitational pull makes sea levels here 348 feet lower than average, creating a 1.2-million-square-mile anomaly southwest of India.
This geoid low formed over the remnants of the Tethys Ocean, a prehistoric body of water that disappeared 180 million years ago when supercontinents Laurasia and Gondwana broke apart.
The gravity hole emerged when fragments of Tethys' crust sank deep into Earth's mantle, displacing dense material. This process began during Gondwana's breakup, according to a 2023 study in Geophysical Research Letters.
The "African blob," a crystallized magma mass 100 times taller than Mount Everest, played a crucial role. Its dense material was displaced by low-density magma plumes, creating the gravity anomaly.
Researchers used 19 computer models to simulate Earth's tectonic activity over 140 million years. These models traced how magma flows and crustal shifts caused the geoid low.
Scientists are now using earthquake data to verify the presence of low-density magma plumes beneath the gravity hole, which could confirm the model’s predictions about mantle activity.
Strange magma formations, like the "African blob," are scattered throughout Earth’s mantle. They reveal surprising complexities in how the planet’s interior functions.
Credit: Cottaar and Lekic/CC by 4.0
Mars, too, hides mysterious magma blobs beneath its surface. Studies of Earth's gravity hole could offer insights into how planetary interiors evolve across the solar system.
The Indian Ocean gravity hole isn’t just a quirk; it’s a gateway to understanding Earth’s tectonic past and the hidden processes shaping our planet’s interior today.