Media release | Hawaiian Volcano Observatory
HAWAI‘I ISLAND, Hawaii — The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded a magnitude-4.6 earthquake located beneath Kilauea volcano’s south flank on Thursday, March 10, at 10:58 p.m. HST. This earthquake was centered about 2 km (1 mi) southwest of Kalapana and 44 km (28 mi) south-southeast of Hilo, at a depth of 9.3 km (5.8 mi).
The earthquake was widely felt on the Island of Hawai’i. The USGS “Did you feel it?” Web site (http://earthquake.usgs.gov/eqcenter/dyfi/) received more than 200 felt reports within two hours of the earthquake.
The earthquake was the largest in a cluster of about 20 earthquakes in the Kalapana area overnight. In addition, there were three earthquakes of magnitude 3.0 and above.
This earthquake sequence is not related to the magnitude-8.9 earthquake in Japan or the subsequent tsunami.
The Kalapana area has been the site of destructive earthquakes in the past. On Nov. 29, 1975, a magnitude-7.2 earthquake caused over $4 million in damages and generated a tsunami that killed 2 people. On June 25, 1989, a magnitude-6.2 earthquake just west of Kalapana caused almost $1 million in damages.
Most earthquakes in the Kalapana area and along the lower south flank of Kilauea are caused by motion of the volcano’s south flank moving southeast over the ocean floor as a result of magma injected into the rift zone. Last night’s magnitude-4.6 earthquake, along with its foreshocks and aftershocks, are consistent with slip along the interface between Kilauea and the ocean floor in response to the intrusion of magma during the Kamoamoa fissure eruption episode earlier in the week.
Last night’s earthquakes were in an area where 10 earthquakes of magnitude 4 or greater have been located in the past 25 years. Historically, this area has shown increased seismic activity during eruptions or when magma intrudes into the east rift zone.
The Kalapana area earthquakes have had no apparent effect on Kilauea or Mauna Loa. HVO monitoring networks have not detected any significant changes in activity at the summits or rift zones of the volcanoes.