USGS Volcano Notice - DOI-USGS-HVO-2025-11-26T18:50:44+00:00

Activity Summary:

Episode 37 lava fountaining occurred yesterday from 2:30 p.m. to 11:39 p.m., totaling just over 9 hours. Fountains were limited to the north vent, which sent lava flows over a large portion of the crater floor. Fountain heights reached 500-600 ft (150-180 meters). The south vent showed only weak spattering and flaming. The summit magma reservoir is now repressurizing, suggesting that another eruptive episode is possible in the coming weeks.  

Summit Observations:

Following several days of precursory overflows and low dome fountaining, episode 37 began yesterday at 2:30 p.m. with lava fountaining from the north vent.  A wide fountain developed, eventually reaching heights of 500-600 ft (150-180 meters), sending flows across a broad portion of the crater floor.  The south vent showed only weak spattering and persistent flaming through the event.  North vent lava fountaining had diminished slightly by 8 p.m., and eventually terminated at 11:39 p.m. No tephra fall was observed on nearby roads. Preliminary estimates suggest that approximately 6 million cubic meters (7.8 million cubic yards) of lava were erupted during episode 37, based on ground deformation data.

The fountaining was associated with sharp deflationary tilt, amounting to about 16 microradians of deflationary tilt on the Uēkahuna (UWD) tiltmeter during the episode. Summit tiltmeters showed the abrupt onset of inflationary tilt with the end of fountaining, as in previous events.  This morning, about 1.5 microradians of inflationary tilt have been recorded by UWD since the end of the episode. Seismic tremor increased significantly during the fountaining, but dropped abruptly to background levels with the end of fountaining.

Gas emissions increased during the lava fountaining yesterday, and the eruptive plume rose to over 14,000 ft (4,200 meters) above sea level.  Sulfur dioxide (SO₂) gas emissions often exceed 50,000 tonnes per day during lava fountaining.  This morning, a passive outgassing plume is visible rising from the vent area.

The following notices provide more information about episode 36:

• VAN VONA End of Episode 36
• VAN VONA Start of Episode 36
• Kilauea Daily Update November 9

The following links provide more information about the current eruption that began on December 23, 2024:

• Eruption resources, including the most recent map and a timeline of eruption episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information
• Three Kīlauea summit livestream videos that show eruptive lava fountains are available here: https://www.youtube.com/@usgs/streams
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams
• Volcano Watch article on gas pistons: https://www.usgs.gov/observatories/hvo/news/volcano-watch-so-what-earth-or-least-kilauea-a-gas-piston

Rift Zone Observations:

Rates of seismicity and ground deformation remain very low in the East Rift Zone and Southwest Rift Zone. SO₂ emissions from the East Rift Zone remain below the detection limit. A magnitude 4.6 earthquake occurred on the south flank yesterday at 11:49 p.m., with shaking reported across the Island of Hawai‘i.  An information statement on the earthquake is available here.

Analysis:

The resumption of inflationary tilt following the end of episode 37 indicates that the summit magma reservoir is repressurizing, suggesting that another eruptive episode is possible in the coming weeks but more monitoring data is needed before an official forecast can be made.  Preliminary models indicate that the next episode is at least a week away.

HVO continues to closely monitor Kīlauea and is in contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency about eruptive hazards.

Please see the Hawaiʻi Volcanoes National Park website for visitor information: https://www.nps.gov/havo/index.htm

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.