Researchers have discovered a sea’s worth of water locked within the sediment and rock of a lost volcanic plateau that’s now deep in the Earth’s crust. Revealed by a 3D seismic image, the water lies two miles under the ocean floor off the coast of New Zealand, where it may be dampening a major earthquake fault that faces the country’s North Island.
The fault is known for producing slow-motion earthquakes, called slow slip events. These can release pent-up tectonic pressure harmlessly over days and weeks. Scientists want to know why they happen more often at some faults than others.
Many slow slip earthquakes are thought to be linked to buried water. However, until now there was no direct geologic evidence to suggest such a large water reservoir existed at this particular New Zealand fault.
Read more at: University of Texas at Austin
The Hikurangi plateau is a remnant of a series of epic volcanic eruptions that began 125 million years ago in the Pacific Ocean. A recent seismic survey (red rectangle) led by the University of Texas Institute for Geophysics imaged the plateau as it sinks into New Zealand’s Hikurangi subduction zone (red line). (Photo Credit: Andrew Gase)