Ta'ū seismicity detected from Wake Island

Earthquakes in oceanic environments can generate pressure waves that travel long distances within the ocean itself. Much like seismographs record ground shaking, this energy is recorded by submerged hydrophones measuring pressure changes in water. Using an array of these instruments located offshore of Wake Island, 2,800 miles (4,500 km) northwest of Ta'ū volcano in American Samoa, we can detect earthquakes from around the Pacific Ocean and determine the direction to their origin. The above plot shows the number of earthquakes coming from the direction of Ta'ū volcano, recorded over time since late July at the Wake Island array. The detections are limited to larger, more notable events, and provide a consistent record of Ta'ū earthquake activity, including events that predate the installation of local seismic monitoring equipment.