USGS Volcano Notice - DOI-USGS-HVO-2025-10-18T07:33:48+00:00

During the lapse in appropriations, the USGS Hawaiian Volcano Observatory (HVO) continues to maintain monitoring networks and issue updates and notifications of volcanic activity via the Hazard Notification Service. Volcano monitoring data will continue to be available on the HVO website. Static website content will not be updated until further notice and information may become outdated over time. For more information on the shutdown, please visit the Department of the Interior website at www.doi.gov.

Activity Summary:

Episode 35 fountains began at about 8:05 p.m. HST from the north vent after about 30 minutes of continuous overflows of degassed lava.  The fountains rapidly grew to about 500 feet (150 meters) when the south vent began erupting at 8:50 p.m. HST.  The south vent fountains grew rapidly and within 20 minutes equaled the north vent fountains in size.  Both fountains have continued to increase in height and by 9:30 p.ml had exceeded 1000 feet (300 meters).  The south vent fountain is currently (10:00 p.m. HST) just under 1500 feet (500 meters) high and the north vent fountains about 1100 feet (330 meters) high.  These would be the highest single fountain and highest pair of fountains seen during this eruption. Sustained high fountains continue from both vents at this time.  

The plume of gas above the fountains extends to over 16,0000 feet (5,000 meters) above ground level.  Tephra is reported by Hawaiʻi County Civil Defense falling on Highway 11 southwest of the vents.  Fine ash and Peleʻs hair can be carried long distances and may impact a broad area of Kaʻu along the southern and southwestern parts of Mauna Loa.

The summit has deflated approximately 7 microradians as measured on the Uēkahuna tiltmeter in about 2 hours. The rapid tilt drop and very high output from both vents suggest this may be another relatively short episode lasting less than 6-8 hours similar to episode 34.

For more information about earlier parts of episode 35 see these notices:  

USGS Volcano Notice - DOI-USGS-HVO-2025-10-17T05:15:25+00:00

USGS Volcano Notice - DOI-USGS-HVO-2025-10-16T21:59:37+00:00

Most episodes of Halemaʻumaʻu lava fountaining since December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days. 

• Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information.
• All eruptive activity is confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park.
• Three Kīlauea summit livestream videos that show eruptive lava fountains are available here: V1cam, V2cam, V3cam.
• KPcam and MKcam provide views of the plume height for aviation purposes.

No changes have been detected in the East Rift Zone or Southwest Rift Zone. 

A VAN/VONA will be issued when sustained high lava fountaining ends, marking the end of episode 35.

Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park.

Hazards: 

This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are one major hazard of concern, as this hazard can have far-reaching effects downwind. As SO₂ is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO₂ and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/.

Another major hazard is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity that can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments (tephra) including volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-3 miles (1-5 kilometers) of the eruptive vent(s), with the highest concentrations immediately downwind of the vent(s). Various volcanic fragments have fallen on Highway 11 west of Hawai'i Volcanoes National Park at times, depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation and can also contaminate catchment water supplies. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf.

Hawaiian lava flows generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera.

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 Kīlauea's caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007.