Geophysicists Trace 106-Meter Indian Ocean Gravity Hole to 140-Million-Year Mantle Flow
Updated
Updated · The Brighter Side of News · May 21
Geophysicists Trace 106-Meter Indian Ocean Gravity Hole to 140-Million-Year Mantle Flow
2 articles · Updated · The Brighter Side of News · May 21
A new modeling study links the Indian Ocean Geoid Low south of India—the ocean surface there sits about 106 meters below surrounding areas—to hot, lighter mantle material beneath the northern Indian Ocean.
Nineteen mantle-convection simulations run from roughly 140 million years ago showed only seven could reproduce the anomaly well; the best-fit case reached a 0.80 regional correlation with observed gravity data.
The researchers say the mass deficit likely stems from the African superplume, with hot material deflected eastward under the Indian Ocean, while ancient Tethyan slabs helped trigger plumes rather than directly creating the low.
Their reconstruction suggests the feature strengthened only around 20 million years ago, when hot upper-mantle material spread closer to the Indian peninsula, and depends on both shallow and deep mantle structure.
Outside experts said the models still miss key features—notably the Réunion plume tied to the 65-million-year-old Deccan Traps—though the work could sharpen broader models of mantle circulation and seismic interpretation.
Why does a massive 'gravity hole' exist in the Indian Ocean without a single volcano on top of it?
If 'ghost plumes' can warp Earth's gravity, what other invisible forces are shaping our planet from deep below?