Seismic activity increases beneath Kīlauea summit

Earthquake activity beneath Kīlauea’s summit and upper East Rift Zone increased over the past 24 hours, Hawaiian Volcano Observatory reported today.

Over the past 24 hours, there were approximately 67 earthquakes detected beneath Kīlauea’s summit and approximately 172 earthquakes detected beneath the upper East Rift Zone, mostly at depths of 0.0–1.2 miles beneath the ground surface.

An increase in earthquake counts was also observed beneath the summit and the upper East Rift Zone compared to the previous day, during which there were approximately 17 events detected beneath the summit, and approximately 61 events detected beneath the upper East Rift Zone.

Substantial increases in seismicity and/or deformation could result in a new eruptive episode. Currently, there are no signs of imminent eruption.

Following the eruption on June 3, magma has been repressurizing the storage system beneath Halemaʻumaʻu and the south caldera region, activating earthquakes in the caldera south of Halemaʻumaʻu and in the upper East Rift Zone.

All earthquake counts are well below the counts recorded during the June 27–July 1 upper East Rift Zone swarm. In the upper East Rift Zone region, there were three seismic events larger than M3 with one earthquake being M3.5.

All seismic events were smaller than M3 earthquakes in the summit region. Tiltmeters in Kīlauea summit region (instruments SDH, southwest of the summit, and UWE, northwest of the summit) show gradual inflationary ground deformation over the past day. GPS instruments around the summit region continue to show longer-term, gradual inflation since the end of the June 3 eruption.

The most recent measurement of the summit’s SO2 emission rate was approximately 100 tonnes per day on July 17.

A map interferogram showing recent deformation at Kīlauea over the timeframe of June 6 to July 8 is available here.

Rates of seismicity and ground deformation beneath the middle and lower East Rift Zone and lower Southwest Rift Zone remain low. Recent eruptive activity and ongoing unrest have been restricted to the summit and upper rift zone regions.

Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō in the middle East Rift Zone—the site of 1983–2018 eruptive activity—remain below detection limits for SO2, indicating that SO2 emissions from Puʻuʻōʻō are negligible.

Hazards remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public.

This underscores the extremely hazardous nature of the rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since early 2008.

Near the recent Southwest Rift Zone eruption site, minor to severe ground fractures and subsidence features may continue to widen and offset, may have unstable overhanging edges, and should be avoided. Hazards associated with the recent lava flows include glassy (sharp) surfaces that can cause serious abrasions, and lacerations upon contact with unprotected or exposed skin; uneven and rough terrain that can lead to falls and other injuries; or, locally elevated levels of volcanic gases that can lead to breathing difficulty.

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

Click here for the Hawaiʻi Volcanoes National Park website for visitor information.