Undersea Observatory Captures Rare Burst of Seafloor Formation
Researchers operating an underwater observatory near Amsterdam Island recorded a rare, hours-long seafloor-spreading event in April 2024: sheet-like magma dikes injected around 150 million cubic meters of magma, forcing a 4.2-meter collapse of the ridge floor and rapid, up-to-5 cm-per-minute displacements. Much of the motion was aseismic, helping explain previously missing tectonic motion and providing a real-time test bed for seismic models. The findings, published in Nature, show seafloor spreading occurs in giant, episodic bursts rather than steady creep.