USGS Volcano Notice - DOI-USGS-HVO-2026-08-29T18:42:24+00:00

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu is paused. Summit inflation proceeded steadily over the past day, but cumulative reinflation since the end of lava fountaining episode 54 has been minimal. Intermittent, moderate glow due to flaming was observed overnight at the north vent. Another lava fountaining episode may occur in the coming weeks if normal tilt patterns resume, but more data are needed to model the forecast window.

No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

A detailed summary of lava fountaining episode 54 on August 25, 2026 can be found below.

NOTE: Significant changes in activity between Daily Updates are posted here: https://www.usgs.gov/observatories/hvo/observatory-messages

Summit Observations:

Overnight webcam views showed intermittent, moderate glow related to flaming at the Halema’uma’u north vent. Release and combustion of volcanic gas (likely hydrogen) appears to be occurring deep within the vent and is related to larger tremor bursts observed in seismic data streams. Little or no glow appears to be coming from incandescent magma, suggesting it is relatively deep and possibly crusted over between gas release tremor bursts. Both the west and south vents were dark, and the latter appears to be partially filled in by north vent spatter and tephra erupted during lava fountaining episode 54. Lava flows on the floor of Halemaʻumaʻu crater still exhibited a few scattered points of incandescence as they cool and solidify after the episode; these points may remain visible for a couple more days and nights.

Low-frequency seismic tremor bursts—typical during the early stages of pauses between eruptive episodes—began with the cessation of episode 54 and have continued through this morning. The larger bursts are related to flames and glow at the north vent and probably represent gas release deep within the vent. Two shallow earthquakes have been recorded beneath the summit region over the past 24 hours. 

Summit inflation proceeded steadily over the past day, although it has slowed slightly this morning. The Uēkahuna (UWD) has only inflated a total of 1.8 microradians relative to the end of lava fountaining episode 54. Deflationary tilt on UWD totaled 12.7 microradians during episode 54.

During inter-episode pauses, the sulfur dioxide (SO₂) emission rate from the summit typically varies between 1,000 and 5,000 tonnes per day. Strong trade winds are pushing the degassing plume to the southwest over the Kaʻū Desert this morning.

Rift Zone Observations:

Rates of seismicity and ground deformation remain low in the East Rift Zone and Southwest Rift Zone. SO₂ emissions from the East Rift Zone remain below the detection limit.

Analysis:

The abrupt switch from summit deflation to inflation at the end of episode 54 and continued glow from the eruptive vents indicate that another lava fountaining episode may occur in the coming weeks if normal tilt patterns resume. Reinflation has been minimal since the end of the episode, and the deflationary tilt that occurred from Wednesday, August 26 through Thursday, August 27 is evidence that unpredictable, stepwise reinflation will likely continue during this repose period—as it has since episode 51. The only significant glow from the north vent at this time is related to gas release and near-surface combustion, suggesting the magma column is relatively deep within the vent.

The current situation—with minimal cumulative reinflation, three and a half days after the end of episode 54—is unique for this eruption. HVO will provide a forecast for the next lava fountaining episode if and when summit inflation stabilizes.

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses of two or more weeks.

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

Summary of episode 54:

A detailed account of episode 54 is given in the HVO Status Report issued on August 25: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-08-26T05:56:38+00:00

• Episode 54 of the ongoing Halemaʻumaʻu eruption began around 10:30 a.m. HST and ended at 7:33 p.m. HST on August 25, 2026, after 9 hours of continuous lava fountaining. 
• The maximum lava fountain height from the north vent was approximately 500 feet (150 meters) above ground level, reached between 12:15 p.m. and 1:00 p.m. HST. Neither the south vent nor the new west vent (formerly the collapse pit) fountained during this episode.
• The maximum plume height was approximately 17,000 feet (5,200 meters) above sea level.
• Most tephra fall was restricted to the closed area of Hawaiʻi Volcanoes National Park, southwest of the active eruptive vents in Halemaʻumaʻu. However, HVO did also receive a report of trace Pele’s hair falling in the Ka‘ū district of the Island of Hawaiʻi.

Resources:

NOTE: HVO’s monitoring network is mostly recovered from recent power- and storm-related outages. Several summit stations will remain offline as we continue working to repair instruments and re-establish connections in our monitoring network.

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
• Short messages tracking the evolution of the lava fountains and eruptive activity can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages
• Three Kīlauea summit livestream cameras 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

Hazards:

This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park.

• Volcanic Gas: High levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are continually released during an eruption. Emissions can remain locally hazardous in the areas immediately downwind of the vents, even when the vents are not actively erupting. SO₂ reacts in the atmosphere to create vog (volcanic air pollution) downwind. SO₂ and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
• Tephra: Small glassy volcanic fragments—volcanic ash, pumice, scoria, Pele’s hair and reticulite—are created by the lava fountains. A combination of fountaining dynamics and wind conditions determines where tephra fall may occur for any given eruption episode. Larger particles fall near the vents while light particles may be wafted greater distances. These particles may be remobilized during windy conditions following recent eruptive episodes. Residents and visitors should minimize exposure to these fragments, which can cause skin, eye, and respiratory irritation. More information and guidance on tephra fall hazards is available at https://seagrant.soest.hawaii.edu/resource-and-guidance-for-volcanic-tephra-fall/
• Lava flows: Lava on the floor of Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera, remains hot and may slowly move in the days immediately following an eruptive episode.

Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. Close to the eruptive vents, the tephra material on the crater rim is prone to cracking, slumping, and small landslides that sometimes expose hot and molten material within. 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.