MEDIA RELEASE

The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded a magnitude-4.2 earthquake north of Moloka‘i on Thursday, March 9, at 3:03 a.m. HST.

This earthquake was centered about 65 km (40 mi) northeast of Kaunakakai, Moloka‘i, at a depth of 17 km km (10.6 mi). A map showing its location is posted on the HVO website at http://hvo.wr.usgs.gov/seismic/volcweb/earthquakes/.

The earthquake was felt throughout the island chain, from HawaiÊ»i to OÊ»ahu, with the USGS “Did you feel it?” website (http://earthquake.usgs.gov/dyfi/) receiving more than 340 felt reports within an hour of the earthquake. Weak to light shaking, with maximum Intensity of IV, has been reported. At that intensity, damage to buildings or structures is not expected.

The Pacific Tsunami Warning Center reported that no tsunami was generated (http://ptwc.weather.gov/?region=2).

The depth, location, and recorded seismic waves of the earthquake suggest a source due to bending of the oceanic plate from the weight of the Hawaiian Island chain, a common source for earthquakes in this area. Aftershocks are possible and could be felt.

The earthquake caused no detectable changes in KÄ«lauea Volcano’s ongoing eruptions, on Mauna Loa, or at other active volcanoes on the Island of HawaiÊ»i.

For information on recent earthquakes in Hawaii and eruption updates, visit the USGS Hawaiian Volcano Observatory website at https://hvo.wr.usgs.gov.

USGS: How large does an earthquake have to be to cause a tsunami?

Magnitudes below 6.5
Earthquakes of this magnitude are very unlikely to trigger a tsunami.

Magnitudes between 6.5 and 7.5
Earthquakes of this size do not usually produce destructive tsunamis. However, small sea level changes may be observed in the vicinity of the epicenter. Tsunamis capable of producing damage or casualties are rare in this magnitude range but have occurred due to secondary effects such as landslides or submarine slumps.

Magnitudes between 7.6 and 7.8
Earthquakes of this size may produce destructive tsunamis especially near the epicenter; at greater distances small sea level changes may be observed. Tsunamis capable of producing damage at great distances are rare in the magnitude range.

Magnitude 7.9 and greater
Destructive local tsunamis are possible near the epicenter, and significant sea level changes and damage may occur in a broader region.

Note that with a magnitude 9.0 earthquake, the probability of an aftershock with a magnitude exceeding 7.5 is not negligible. To date, the largest aftershock recorded has been magnitude 7.1 that did not produce a damaging tsunami.