USGS Volcano Notice - DOI-USGS-HVO-2023-02-02T00:19:21-08:00

Activity Summary: The summit eruption of Kīlauea Volcano, within Halemaʻumaʻu crater, continued over the past 24 hours. All recent eruptive activity has been confined to the crater. No significant changes have been observed at the summit or in either rift zone.

Halemaʻumaʻu Lava Lake Observations: Eruption of lava in the eastern portion of Halemaʻumaʻu crater floor continued over the past 24 hours. Activity in the large eastern lava lake began to crust over yesterday morning and formed an isthmus of crust through the center of the lake with two smaller patches of lava on the north and south sides by yeseterday afternoon.  Combined, the two active areas in the eastern lake were roughly half of the 25 acre size measured on Jan 17, and each showed independent and opposite surface convection directions from the levees towards the isthmus/former center of lake.  The lava fountain in the eastern lake (southern part) disappeared for roughly 45 minutes at 11:15 pm HST last night, but returned at midnight.  By 1 am HST, the lava surface from the southern part of the eastern lake was flooding across the total eastern lake area bounded by levees, covering the lava crust isthmus and returning to most of the original 25 acre size by 4 am HST this morning.  The eastern lake remains stable and hasreturned to a single lake surface at the time of this post.  The smaller western lake in the basin of the 2021–2022 lava lake as well as the two smaller lava ponds remained unchanged through all of this activity yesterday, however one of the smaller ponds (closest to the eastern lake) produced an overflow during the 30 minutes prior to this post.   A live-stream video of the lava lake is available at: https://www.youtube.com/usgs/live.

Summit Observations: Summit tiltmeters started showing an inflationary trend around 11 pm HST and has begun to level off this morning. Volcanic tremor remains above background levels. A sulfur dioxide (SO₂) emission rate of approximately 3,000 tonnes per day (t/d) was measured on January 20, 2023. 

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 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.