USGS Volcano Notice - DOI-USGS-HVO-2023-08-23T14:54:31-07:00

Activity Summary: Kīlauea volcano is not erupting. Kīlauea summit is currently exhibiting signs of elevated unrest. No unusual activity has been noted along Kilauea’s East Rift Zone or Southwest Rift zone. 

Summit Observations: This morning, from about 4:30 to 8:30 am, an earthquake swarm of approximately 50 earthquakes occurred at a depth of 1-2 miles (2-3 km) below the surface, south of Halemaʻumaʻu crater. This is the fourth earthquake swarm in this area in the past week, and is likely caused by movement of magma in Kīlauea's south caldera region. The recent general trend of inflationary tilt on summit tiltmeters continued through the past day. The earthquake swarms and tiltmeter data indicate that Kīlauea summit is still exhibiting signs of elevated unrest. Sulfur dioxide (SO₂) emissions from the summit remain low; the most recent SO₂ emission rate, of approximately 86 tonnes per day, was measured on August 15.

Halemaʻumaʻu Lava Lake Observations: No active lava has been observed since June 19. A live-stream video of the inactive western lava lake area is available at https://www.youtube.com/usgs/live.

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 at the base of Halemaʻumaʻu crater, within the closed area of Hawaiʻi Volcanoes National Park. During Kīlauea summit eruptions, the high level of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—being emitted is the primary hazard of concern, as this hazard can have far-reaching effects downwind. Passive volcanic degassing can occur from within Halemaʻumaʻu crater even during periods of no eruptive activity. 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.   
 
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. 
 
The Hawaiian Volcano Observatory (HVO) continues to closely monitor Kīlauea Volcano. 

Next Notice: HVO will issue daily Kīlauea updates. Additional messages will be issued as needed.