Summit eruption at Kīlauea has ‘greatly diminished’

The summit eruption of Kīlauea Volcano, within Halemaʻumaʻu crater, has greatly diminished over the past 24 hours. All recent eruptive activity has been confined to the crater.

While Eruption of lava on the Halemaʻumaʻu crater floor continues, no significant changes have been observed in either rift zone.

According the Hawaiian Volcano Observatory’s daily update, the eastern and central vents are not erupting. The western lake in the basin of the 2021–22 lava lake remains active but with weak lava flows. Very little lava is circulating within the lake, which is mostly crusted over with intermittent crustal overturns.

“The reduction in activity is related to the larger deflationary tilt drop that began in the early morning of February 17,” the update indicated. “Surface eruptive activity is expected to resume when the summit re-inflates to the level preceding the strong deflation.”

A live-stream video of the western lava lake is available at: https://www.youtube.com/usgs/live.

Over the past 24 hours, summit tiltmeters showed deflation of of about 2 microradians until about 10:30 p.m. on Monday that turned into inflation of about 1.5 microradians that continues as of 8:15 a.m. today.

According to the update, volcanic tremor has dropped slightly but remains above background levels. A sulfur dioxide (SO2) emission rate of approximately 2,000 tonnes per day (t/d) was measured on Feb. 13, 2023.

This eruption at Kīlauea’s summit is occurring within a closed area of Hawaiʻi Volcanoes National Park. High levels of volcanic gas are the primary hazard of concern, as this hazard can have far-reaching effects downwind. Large amounts of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are continuously released during eruptions of Kīlauea Volcano.

As SO2 is released from the summit, it reacts in the atmosphere to create the visible haze known as vog (volcanic smog) that has been observed downwind of Kīlauea. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock. For more information on gas hazards at the summit of Kīlauea, see: https://pubs.er.usgs.gov/publication/fs20173017. Vog information can be found at https://vog.ivhhn.org.

Other significant hazards also 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.

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. 

Visitors to Hawaiʻi Volcanoes National Park should note that under southerly (non-trade) wind conditions, there is potential for a dusting of powdery to gritty ash composed of volcanic glass and rock fragments. These ashfalls represent a minor hazard, but visitors should be aware that such dustings at areas around the Kīlauea summit are possible.