Magnitude 4.0 Quake at Loihi Seamount Shook Big Island off Hawaii

An earthquake at an active underwater volcano southwest of Hawaii shook the Big Island on Wednesday night. According to the U.S. Geological Survey's Hawaiian Volcano Observatory, the earthquake reached a magnitude of 4.0 and originated under the Loihi seamount, about 20 miles southwest of the Big Island of Hawaii and reached a depth of 7 miles.