4.1 Kīlauea Earthquake Consistent with Motion Along South Flank Detachment Fault

A 4.1 earthquake beneath Kīlauea Volcano’s south flank occurred at 2:09 p.m. on Monday, Feb. 1, 2021.

There were no immediate advisories issued by the Pacific Tsunami Warning Center.

Scientists with the US Geological Survey’s Hawaiian Volcano Observatory say that as of 3 p.m., the earthquake had no immediate observable impact on the ongoing eruption at Kīlauea’s summit.

The USGS “Did you feel it?” service (http://earthquake.usgs.gov/dyfi/) received over 270 felt reports within the first hour of the earthquake. While the quake was mostly felt by individuals on Hawaiʻi Island, it was felt as far away as Hāna in East Maui.  

Kīlauea’s south flank has been the site of over 30 earthquakes of magnitude-4.0 or greater during the past 20 years. According to the HVO, most are caused by abrupt motion of the volcano’s south flank, which moves to the southeast over the oceanic crust.

“The location, depth, and waveforms recorded as part of today’s earthquake are consistent with motion along the south flank detachment fault,” according to the HVO.

The earthquake was centered about 8 miles south of Fern Forest, near the Hōlei Pali area of Hawai‘i Volcanoes National Park at a depth of 4 miles.

The HVO reports that the quake generated weak to light shaking, and damage to buildings or structures was not expected at the recorded intensity.

“This earthquake was widely felt across the Island of Hawai‘i. Please be aware that aftershocks are possible and may be felt. HVO continues to monitor Hawaiian volcanoes for any changes,” said HVO Deputy Scientist-in-Charge David Phillips.