Buried Sea Discovery Could Explain Slow-Motion Earthquakes

Beneath the Pacific Ocean, off the coast of New Zealand, lies a sea's worth of water, locked within the Earth's crust. Researchers believe that this sunken reservoir may play an important role in dampening the strength of earthquakes in the Western Pacific.

We tend to think of earthquakes as sudden, often violent events that take place over a matter of seconds. But energy can also be released from the Earth's crusts in slow motion, over a period of weeks or months. These are called slow slip events and they occur when tectonic plates get temporarily locked together as one attempts to slide past the other.

New Zealand sits at the boundary of two major tectonic plates: the Australian Plate and the Pacific Plate. The boundary between these plates is known as a fault, and this particular Australian-Pacific fault is known for producing these slow-motion earthquakes. But, while experts believe many slow slip earthquakes are associated with buried water under the Earth's crust, no direct geological evidence for an underground reservoir has been found at this particular site. Until now.

Full story features WWU geologist Andrew Gase.