USGS Volcano Notice - DOI-USGS-HVO-2023-09-13T11:35:42-07:00

Activity Summary: The Kīlauea summit eruption that began on September 10th continues this morning. Eruptive activity is confined to the downdropped block and Halemaʻumaʻu crater within Kīlauea's summit caldera. No unusual activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone. 

Halemaʻumaʻu Lava Lake Observations: Several vents continue to erupt on the western side of the downdropped block within Kīlauea's summit caldera and are generating lava flows onto Halema‘uma‘u crater floor. The roughly east-west trending active vents span approximately 0.5 miles (750 m) and had lava fountain heights of up to about 10 meters (32 feet) yesterday. From the erupting vents, pāhoehoe lava flows continue to travel in north and west directions onto Halema‘uma‘u crater floor; however, the area of active lava has retreated towards the vents compared to yesterday. This morning, active lava appears to be flowing only on the north and east parts of Halema‘uma‘u, the eastern boundary of which has been mostly covered by lava flows. The area north of the eruptive vents has become perched and is about 3 meters (15 feet) higher than the surrounding ground surface. Effusion rates appear down from initial eruptive rates, but remain high. The laser rangefinder is aimed at a western portion of Halema‘uma‘u, not near the new eruptive activity, and recorded nearly 6 m (20 feet) of uplift to this locality since the eruption started. This demonstrates that a significant amount of lava has intruded beneath the pre-existing crust within Halema‘uma‘u.

• A live-stream video of the eruption is available at https://www.youtube.com/usgs/live.
• More eruption information is available at: https://www.usgs.gov/volcanoes/kilauea/recent-eruption. 

Summit Observations: Summit tilt has remained deflationary over the past 24 hours. Summit seismic activity is dominated by eruptive tremor (a signal associated with fluid movement) with very few volcano tectonic earthquakes. Volcanic gas emissions in the eruption area are elevated; a sulfur dioxide (SO2) emission rate of 30,000 tonnes per day was measured yesterday morning, September 10.  This is down significantly from the 190,000 tonnes per day measured just after the onset of the eruption on Sunday, September 10th.

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—the site of 1983–2018 eruptive activity—remain below detection limits for SO₂, indicating that SO₂ emissions from Puʻuʻōʻō are negligible.

Hazard Analysis: Eruptive activity is occurring on the downdropped block and Halemaʻumaʻu crater, within Kīlauea's summit caldera and in the closed area of Hawaiʻi Volcanoes National Park. During Kīlauea summit eruptions, the high level of volcanic gases—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)— and fine volcanic particles are the primary hazards of concern, as these hazards can have far-reaching effects downwind.

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.

Strong winds may waft fine rock particles to areas downwind of erupting vents. People should minimize their exposure to these fine volcanic particles, which can cause skin and eye irritation.  Reports from Hawaiian Volcano Observatory field crews indicate that fine particles of Pele's Hair and other tephra are being deposited in the area near the Keanakāko‘i Overlook, which is approximately half a mile (about 1 km) from the eruption site. Hawaiʻi Volcanoes National Park has closed the Keanakāko‘i Overlook to the public at this time.

Other significant hazards also remain around Kīlauea's summit 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.