Small earthquake swarm briefly rattles Kīlauea summit Thursday

A small brief swarm of earthquakes rumbled Kīlauea’s summit caldera Thursday night. The volcano continues to exhibit signs of unrest, however, it is not erupting.

Steady rates of earthquakes have persisted in the area south of Kīlauea’s summit caldera since Aug. 22, according to Hawaiian Volcano Observatory. Most of these earthquakes have occurred at depths of 1–2 miles below the surface, with no upward migration detected. No unusual activity has been noted along the volcano’s East Rift Zone or Southwest Rift Zone.

No active lava has been observed since June 19. A live-stream video of the inactive western lava lake area is available at https://www.youtube.com/usgs/live.

The seismic and tilt data indicate that Kīlauea’s summit is becoming increasingly pressurized. Similar episodes of earthquake and ground deformation activity occurred in November 2020 and August 2021, prior to eruptions in December 2020 and September 2021. The unrest is currently confined within Kīlauea’s summit region and—if it continues—could escalate to an eruption in the coming days, weeks, or months.

The activity could also decrease due to the intrusion of magma underground or other changes, resulting in no eruption. Furthermore, levels of activity are expected to rise and fall during this period of unrest.

Summit tiltmeters have tracked mostly steady inflation since Tuesday, following a longer-term period of gradual inflation dating back to the end of the last eruption in June. Sulfur dioxide emissions from the summit remain low; the most recent SO2 emission rate of approximately 75 tonnes per day was measured on Aug. 24.

For discussion of Kīlauea hazards, see https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.

See the Hawaiʻi Volcanoes National Park website for visitor information: https://www.nps.gov/havo/index.htm.