UPDATE: No Tsunami Threat From 4.2-M Loihi Seamount Quake

August 22, 2019, 6:14 AM HST (Updated August 22, 2019, 7:28 AM)


The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded an offshore magnitude-4.2 earthquake south of the Island of Hawai‘i on Thursday, Aug. 22, 2019, at 4:33 a.m., HST.

The earthquake was centered about 35 miles SE of Pāhala, Hawai‘i, at a depth of 29 miles.

Weak shaking, with maximum Intensity of III, has been reported from around the Island of Hawai‘i. At that intensity, damage to buildings or structures is not expected. The USGS “Did you feel it?” service  received 30 felt reports within two hours of the earthquake.


According to Brian Shiro, HVO’s Seismic Network Manager, the earthquake was located 6 miles south of the summit of Lō‘ihi seamount, but does not appear to be associated with the submarine volcano.

“The earthquake was most likely due to bending of the Earth’s crust under the weight of Hawai‘i Island,” he said.

Lō‘ihi is an active submarine volcano located on the seafloor south of Kīlauea Volcano about 19 miles off the southeast coast of the Island of Hawai‘i. The seamount is 3,180 feet below sea level. It last erupted in 1996.

Today’s earthquake had no apparent effect on Kīlauea or Mauna Loa volcanoes, and the Pacific Tsunami Warning Center reported that no tsunami was generated by it.

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

5:30 AM, Thursday, Aug. 22, 2019: Civil Defense Local Earthquake Message 

The Pacific Tsunami Warning Center reports the earthquake which occurred at approximately 4:34 a.m. in the vicinity of Loihi Seamount was not large enough to cause a tsunami for the Island of Hawai‘i.

Preliminary data indicates that the earthquake measuring a magnitude of 4.0 was centered in the vicinity of Loihi Seamount southeast of Hawai‘i Island.

As in all earthquakes, be aware of the possibility of after-shocks. If the earthquake was strongly felt in your area, precautionary checks should be made for any damages; especially to utility connections of gas, water and electricity.

-155.2365, 18.8383333
46.04 km (28.6 mi)
2019-08-22 04:33:30 local
2019-08-22 14:33:30 UTC
Age: 0.1 days
Distance From:
57km SSE of Pahala, Hawaii


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