USGS Volcano Notice - DOI-USGS-HVO-2023-03-05T10:18:37-08:00

Activity Summary: The summit eruption of Kīlauea Volcano, within Halemaʻumaʻu crater, continues at greatly reduced activity levels compared to several weeks ago. All recent eruptive activity has been confined to the crater. No significant changes have been observed along either of the volcano's rift zones.

Halemaʻumaʻu Lava Lake Observations: Eruption of lava on the Halemaʻumaʻu crater floor continues to be greatly diminished. The eastern and central vents that were active earlier in the eruption are not effusing any lava at this time. The western lava lake—within the basin of the 2021–2022 lava lake—remains weakly active with slow circulation and intermittent crustal overturns, but its footprint has shrunk substantially in recent days. The reduction in activity is related to a large deflationary tilt signal that began on February 17. A live-stream video of the western lava lake is available at https://www.youtube.com/usgs/live.

Summit Observations: Following a large deflationary tilt signal that began on February 17 and lasted until early February 19, summit tiltmeters have tracked several smaller deflation/inflation (DI) events. Over the course of these DI events there has been a slight increase in net tilt, but the summit remains deflated compared to the period leading up to February 17. More vigorous eruptive activity on the Halemaʻumaʻu crater floor may resume if the summit re-inflates to the prior level. Volcanic tremor has dropped slightly in recent weeks, but it remains above background level. A sulfur dioxide (SO₂) emission rate of approximately 250 tonnes per day (t/d) was measured on February 28.

Rift Zone Observations: No unusual activity has been noted along the East Rift Zone or Southwest Rift Zone; steady rates of ground deformation and seismicity continue along both. Measurements from continuous gas monitoring stations downwind of Puʻuʻōʻō—the 1983–2018 eruptive vent—in the middle East Rift Zone have been below detection limits for SO₂, indicating that SO₂ emissions from Puʻuʻōʻō are negligible. 

Hazard Analysis: 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, please see: https://pubs.er.usgs.gov/publication/fs20173017. Vog information can be found at https://vog.ivhhn.org. 

Additional hazards include Pele's hair and other lightweight volcanic glass fragments from lava fountains that will fall downwind and dust the ground within a few hundred meters (yards) of the erupting fissure vent(s). Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation. 

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, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.

Please 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. 

The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea volcano.

HVO will continue to issue daily Kīlauea volcano updates until further notice. Additional messages will be issued as needed.