The U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) recorded a magnitude-4.0 earthquake located under the south part of the Island of Hawai‘i on Monday, January 31, at 1:55 a.m.
The earthquake was centered approximately 5 miles east-northeast of Pāhala, at a depth of 20 miles. A map showing its location is posted on the HVO website at http://volcanoes.usgs.gov/hvo/earthquakes/. More details are available at the National Earthquake Information Center website at https://earthquake.usgs.gov/earthquakes/eventpage/hv72897042/.
Light shaking, with maximum Intensity of IV on the Modified Mercalli Intensity Scale, has been reported across parts of the Island of Hawai‘i. At that intensity, significant damage to buildings or structures is not expected. The USGS “Did you feel it?” service (http://earthquake.usgs.gov/dyfi/) received 48 felt reports within the first hour of the earthquake.
In a statement HVO seismologist Jefferson Chang said, “This earthquake appears to be part of the seismic swarm under the Pāhala area, which has been going on for over a year. Out of over ten thousand earthquakes that were detected in the area over the past year, four have been magnitude-4 or greater.” In addition, HVO Scientist-in-Charge Ken Hon said, “The earthquake had no apparent effect on Kīlauea or Mauna Loa volcanoes. The eruption in Halema‘uma‘u at Kīlauea summit resumed yesterday evening and we do not see any detectable changes in that eruption as a result of these earthquakes.” HVO continues to monitor Hawaiian volcanoes for any changes.
Earthquakes beneath Kīlauea’s lower Southwest Rift Zone are produced mostly at depths of 15-25 mi beneath the town of Pāhala and extending about 6 mi offshore. Earthquakes in this region have been observed at least as far back as the 1960s and are posited to be related to deep magma pathways under the island.
More information on recent earthquakes in Hawaii and eruption updates can be found by visiting the USGS Hawaiian Volcano Observatory website at https://www.usgs.gov/observatories/hvo.