USGS Volcano Notice - DOI-USGS-HVO-2025-11-24T18:23:54+00:00

Activity Summary:

Periodic dome fountain overflows from the south vent ceased just after midnight last night; however, strong glow and intermittent spatter continued throughout the night. No overflows have been recorded at north vent since early Saturday morning. After two minor deflationary events yesterday, inflation continues to be recorded by summit tiltmeters. We are currently in the forecast window for episode 37. Following yesterday's deflation, new models forecast episode 37 to occur between November 25 and November 28, with a slight possibility through today.  

Summit Observations:

Periodic dome fountain overflows from the south vent continued yesterday at a rate of approximately once per hour, with each flow lasting roughly 30-40 minutes. The last overflow ceased at 12:10 a.m. last night, replaced by strong glow and occasional spatter. North vent has continued to glow, though little spatter and no overflows have been seen since early Saturday morning. There have been 73 overflows from the summit vents since overflows began on Friday at 9:30 a.m. HST. Overflows alternated between the vents on Friday but have been largely from the south vent since Friday evening. Temporary increases in tremor were associated with lava drain back during overflow events. 

Low level seismic tremor continues to be recorded from the summit, with minor tremor bursts suggesting a return to gas pistoning behavior at the vents. 

Two deflationary events were recorded yesterday with a total of -0.6 microradians of deflationary tilt recorded at the Uēkahuna tiltmeter (UWD) tiltmeter. Inflation resumed at the summit upon cessation of overflows. The Sandhill (SDH) and Summercamp (SMC) tiltmeters are recording a steady climb compared to UWD, which has recorded little movement overnight. 

Plumes of gas are visible from both the south and north vents. Sulfur dioxide (SO₂) gas emissions increased yesterday to approximately 4000 tonnes per day during a period of deflation, but have since returned to typical eruption pause levels, between 1,200 and 1,500 tonnes per day.

Episode 36 began at approximately 11:15 a.m. HST on November 9 and ended at 4:16 p.m. HST, after erupting for 5 hours. The north vent stopped earlier, at 3:38 p.m. HST, and the south vent gradually decreased in height and volume until it stopped erupting at 4:16 p.m. HST. South vent fountains reached heights of about 1,200 feet (360 meters) and north vent fountains reached heights of about 750 feet (230 meters). Episode 36 fountains produced just under 11 million cubic yards (about 8 million cubic meters) of lava. The combined average eruption rate was over 600 cubic yards per second (500 cubic meters per second) from the dual fountains. Lava flows from the fountains covered about 80 percent of the floor of Halemaʻumaʻu crater. The Uēkahuna tiltmeter (UWD) recorded 23.5 microradians of deflationary tilt during episode 36. The end of the episode was coincident with a rapid change from deflation to inflation at the summit and a decrease in seismic tremor intensity.

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, with no significant earthquake activity in the past 24 hours. SO₂ emissions from the East Rift Zone remain below the detection limit.

Analysis:

Overflows ceased just after midnight and tremor decreased at the same time, both indicating magma level has dropped in the conduits. Both vents continued to glow throughout the early morning hours. Yesterday, summit tiltmeters recorded two minor deflationary events from the shallow Halema'uma'u magma reservoir, but overall inflation at the summit continues at a steady pace. These events have reset the inflation based models, pushing the forecast window back. The new models suggest episode 37 is most likely to occur between November 25 to November 28 with a slight change of it starting today, November 24. This forecast may change if unexpected deflation events occur. Previous episodes have been preceded by hours to days of precursory overflows of degassed magma from the vent, similar to what has been occurring since Friday, November 21.

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.