Swarm of Earthquakes Resume Beneath Kīlauea Summit Caldera

August 27, 2021, 3:00 AM HST
* Updated August 27, 1:15 PM
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The US Geological Survey’s Hawaiian Volcano Observatory (HVO) detected a resumption in earthquake activity and ground deformation beneath the south part of Kīlauea summit caldera, within Hawaiʻi Volcanoes National Park.

The rate of ground deformation began increasing again around 6 p.m. on Aug. 26 and was followed by increased earthquake activity after 8:30 p.m. The renewed activity occurred in approximately the same location as the Aug. 23-25 earthquake swarm—within and south of Kīlauea caldera. The combination of these observations indicates a second pulse of intrusive activity.

Most earthquakes in this renewed swarm were located 0.6–1.8 miles beneath the surface, similar to the initial swarm. Approximately 200 earthquakes have been recorded since 8:30 p.m. on Aug. 26, less than half of the number of earthquakes detected in the initial August 23–25 swarm.

The largest recorded earthquake was magnitude 2.8, with the majority of earthquakes less than magnitude 1. Between 8:30 p.m. on Aug. 26 and 5 a.m. on Friday, Aug. 27, small earthquakes occurred at 16 detected earthquakes per hour, with a peak rate of 24 detected earthquakes per hour just after midnight.

Since 5 a.m. on Aug. 27, the average seismicity rate has dropped to about six detected earthquakes per hour.


As of this afternoon, both earthquake and ground deformation rates in Kīlauea’s summit region appear to be decreasing. In addition, there has been no indication of upward migration of earthquakes toward the surface or change in deformation that would indicate shallowing of the source intrusive activity.


Kīlauea’s Volcano Alert Level and Aviation Color Code remains at ADVISORY/YELLOW.

While the activity has slowed down as of this morning, additional intrusion pulses are possible. Any potential eruptive activity related to these events would be entirely within Hawaiʻi Volcanoes National Park and localized within undeveloped areas, well away from infrastructure such as roads.

For information on recent earthquakes in Hawaii, visit the USGS Hawaiian Volcano Observatory website at


More Information:
Kīlauea activity summary is also available by phone: 808-967-8862
Kīlauea webcam images:
Kīlauea photos/video:
Kīlauea lava-flow maps:
Kīlauea FAQs:


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