Seafloor at Indian Ocean Ridge Collapsed 14 Feet and Expanded 3 Feet During 2024 Tremors

Scientists recorded the birth of new seafloor in real time for the first time during a 2024 series of tremors at the Southeast Indian Ridge between Australia and Antarctica, nypost.com reported. The observation appeared in the journal Nature in 2026. The event added three feet to the Indian Ocean floor.

Researchers had installed the OHA-GEODAMS observatory at the ridge several months earlier. The station carried five autonomous hydrophones, pressure sensors and additional instruments. The valley floor at the ridge collapsed 14 feet.

Tectonic plates separated at nearly 5 centimeters per minute, a rate roughly one million times faster than the long-term average. Lava emerged one or two kilometers from the instruments. Marine geophysicist Jean-Yves Royer of the French National Center of Scientific Research said the team had not expected to capture such a large event.

He added that the instruments remained in place by chance and that the lava flow spared the sensors from damage. Royer noted the group had aimed to measure only a few centimeters of gradual stretching. Instead the instruments recorded several meters of displacement in both directions during what he described as a once-in-forty-year occurrence.

The measurements showed that seafloor formation proceeds in abrupt lurches rather than continuous motion. Royer stated the results open new horizons for marine geophysicists.