Scientists Observe Real-Time Formation of New Oceanic Crust in the Indian Ocean

A French-led research team installed a suite of sensors on the seafloor near Amsterdam Island, a French overseas territory in the southern Indian Ocean, during February 2024. Using hydrophones, acoustic beacons and pressure gauges aboard the oceanographic vessel Marion Dufresne, they recorded a rapid episode of seafloor expansion on the Southeast Indian Ridge.

Over a period of about 16 days the instruments detected a swarm of small earthquakes followed by larger tremors, vertical subsidence of up to 4.2 m and lateral displacement of more than 1 m. The data show that roughly 160 million m³ of lava erupted through newly formed fissures, creating fresh oceanic crust. The observations, published in *Nature*, represent the first direct, real‑time view of such a crust‑forming event. The authors note that “the large‑scale aseismic slip driven by magmatic processes could be the primary mechanism by which normal ocean‑ridge faults accumulate displacement.”