An Undersea Water Reservoir may be Muffling Earthquakes

April 3, 2024

A newly discovered offshore water reservoir in the Earth’s crust may be dampening a major earthquake fault near New Zealand’s North Island, according to researchers at the University of Texas Institute for Geophysics (UTIG).

The fault is known for producing slow-motion earthquakes that help harmlessly release tectonic pressure. Former UTIG postdoc Andrew Gase, who led the discovery, called for drilling to determine how the water affects the fault.

“We can’t yet see deep enough to know exactly the effect on the fault, but we can see that the amount of water is actually much higher than normal,” said Gase, who’s now at Western Washington University.

Published in the journal Science Advances, the discovery was made after analyzing subsurface 3D images from an earlier seismic cruise led by UTIG’s Nathan Bangs.

The water is locked in a lost volcanic plateau that formed when a vast plume of lava breached the surface 125 million years ago. The event was one of Earth’s largest known volcanic eruptions.