USGS Volcano Notice - DOI-USGS-HVO-2023-01-02T20:48:13-08:00

Activity Summary: Kīlauea volcano is not erupting. All recent eruptive activity within Halemaʻumaʻu crater has ceased. Seismic activity is variable, with occasional periods of heightened seismicity beneath and surrounding the crater. No other significant changes have been observed at the summit or in either rift zone.

Summit Observations: This past week saw variable seismic activity in the Kīlauea summit region. There have been occasional periods of heightened seismicity beneath and surrounding Halemaʻumaʻu crater, including a small earthquake swarm in the evening of December 30, 2022. Another small swarm began late yesterday evening, January 2, 2023, and has continued into this morning. A M4.0 earthquake north of the summit region at 3:31 a.m. this morning did not have any obvious effect on volcanic unrest. Volcanic tremor remains weak to nonexistent.

Summit tiltmeters tracked several multi-day deflation-inflation (DI) events over the past week, which have decreased in magnitude compared to earlier DI events. Over longer timescales, summit tiltmeters and GPS continue to show long-term inflationary trends. Gas emissions from the summit remain low; a sulfur dioxide (SO₂) emission rate of approximately 150 tonnes per day (t/d) was measured on December 28, 2022.

Halemaʻumaʻu Lava Lake Observations: Lava is no longer erupting from the western vent into the lava lake on Halemaʻumaʻu crater floor. The lava lake surface has cooled to form a dark crust. There has been no crustal overturn, and only one small source of incandescense—in the center of the crater floor—remains weakly visible in nighttime webcam views. Measured last on December 29, 2022, the total cumulative rise of the crater floor has been about 144 meters (472 feet), and 112 million cubic meters (29.5 billion gallons) of lava had been effused since the beginning of the latest eruption on September 29, 2021.

East 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 remain below detection limits for SO₂, indicating that SO₂ emissions from Puʻuʻōʻō are negligible.

Hazard Analysis: The latest eruptive activity at Kīlauea's summit occurred within a closed area of Hawaiʻi Volcanoes National Park. High levels of volcanic gas was 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. Even during periods of no eruptive activity passive volcanic degassing from the summit and the lava lake still release volcanic gases. 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.  

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.   

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.  
 
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 weekly Kīlauea Volcano updates until further notice. Additional messages will be issued as needed.