4.2 Earthquake SE of Volcano, Hawaiʻi: Adjusting South Flank

Image credit: HVO

The US Geological Survey’s Hawaiian Volcano Observatory recorded a magnitude-4.2 earthquake on Saturday, April 27, 2019, at 5:26 p.m. HST.

The earthquake was located about 20 km (12 mi) southeast of Volcano on the Island of Hawaiʻi at a depth of 6 km (~4 mi). This earthquake is part of the continuing adjustments beneath the south flank of Kīlauea following the magnitude-6.9 earthquake that occurred on May 4, 2018.

Twenty seconds before the magnitude-4.2 earthquake, a magnitude-1.6 quake occurred deep beneath Kīlauea Volcano’s Southwest Rift Zone, causing some initial confusion about the larger earthquake’s location.

A map showing the location of both earthquakes is posted on HVO’s website at https://volcanoes.usgs.gov/observatories/hvo/hvo_earthquakes.html. More details about the magnitude-4.2 earthquake are available at the National Earthquake Information Center website at https://earthquake.usgs.gov/earthquakes/eventpage/hv70927626/.

Weak to light shaking, with a maximum Intensity of IV on the Mercalli Intensity Scale, has been reported primarily in East Hawaiʻi, with a few reports from West Hawaiʻi. The USGS “Did you feel it?” service (http://earthquake.usgs.gov/dyfi/) received over 100 felt reports within an hour of the magnitude-4.2 earthquake.

The earthquakes have caused no detectable changes in activity at either Kīlauea or Mauna Loa volcanoes.

According to the Pacific Tsunami Warning Center (PTWC) no tsunami was generated by the earthquake.