Disaster Discourse: The Hagerty Blog

Kīlauea volcano erupts, 4.4-magnitude earthquake recorded on Hawaii’s Big Island

Overnight, the United States Geological Survey (USGS) confirmed an eruption of the active shield volcano Kīlauea on Hawaii’s Big Island. The eruption began at approximately 9:30 p.m. Hawaii Standard Time (HST) on Sunday, December 20. The eruption started within Kīlauea’s summit caldera inside the Halema’uma’u crater. 

The USGS Hawaiian Volcano Observatory (HVO) also recorded a magnitude-4.4 earthquake beneath Kīlauea Volcano’s south flank on Sunday, December 20, at 10:36 p.m. HST. The earthquake swarm was followed by ground deformation detected by tiltmeters. The epicenter of the earthquake is located approximately 8.7 miles south of Fern Forest on the Big Island, at a depth of four miles, while reports of light shaking with a maximum intensity of IV was reported across the Big Island, according to the USGS. There were more than 500 “felt” reports within the first hour of the earthquake on the USGS “Did you feel it?” service.

Kīlauea Summit Eruption: USGS

The HVO raised Kīlauea’s volcano alert level to “WARNING” and its aviation color code to “RED.” The National Oceanic and Atmospheric Administration (NOAA) reported that periods of ashfall were a strong possibility from Kīlauea Volcano. Low-level trade winds are expected to propel embedded ash in a southwestern direction, with ash fallout likely taking place over the Kau District and Highway 11 (southwest of the volcano in Hawaii), and affected communities including Pahala, Wood Valley, Naalehu, and Ocean View. The Hawaii County Civil Defense Agency, citing the HVO, spoke with The New York Times to caution people to “stay indoors to avoid exposure to ash” since trade winds would push ash to the southwest and into the fallout path of several Census-designated areas of hundreds of people in Pahala, Wood Valley, Naalehu, and Ocean View.

USGS Volcanoes: Twitter

The USGS noted that the south flank of Kīlauea has experienced more than 30 earthquakes of magnitude-4.0 or greater over the past two decades. In 2018, Kīlauea erupted with lava flowing from May through August, destroying over 700 homes and residential areas in the Puna District, southeast of the Waiakea Forest Reserve on the Big Island, according to the National Park Service (NPS). The summit area of the park simultaneously experienced tens of thousands of earthquakes, ash plumes, and the collapse of the Kīlauea caldera. The Federal Emergency Management Agency (FEMA) provides information on Volcano safety during and after an eruption.

Kilauea eruption in Halemaʻumaʻu: NPS