USGS Volcano Notice - DOI-USGS-HVO-2026-08-25T17:38:51+00:00

Overview:

Kīlauea volcano is erupting precursory overflows this morning from the north vent, following its typical pattern before lava fountaining episodes.  Summit inflation continued until about 6:00 a.m. HST when it leveled out, with deflationary tilt starting around 9 a.m. Episode 54 lava fountaining is expected to start today, if activity follows the pattern of previous episodes. 

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

A summary of episode 53 that ended August 13 is posted below.

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

Summit Observations:

Weak spattering was observed overnight from the north vent, with nearly continuous spattering occurring after midnight.  The first precursory overflow and small dome fountain occurred from 6:16 to 6:37 a.m. Several subsequent precursory overflows have occurred since that time. 

Continuous low-level seismic tremor occurred over much of the past day, switching to episodic tremor overnight. These spikes in tremor are normally associated with gas pistoning, and tremor fluctuations have occurred with the overflows this morning.  There was one earthquake recorded in the summit area in the past 24 hours. 

The Uēkahuna tiltmeter (UWD) showed continuing rapid tilt over the past day until about 6:00 a.m. HST when it flattened out.  Tilt is currently deflating.  UWD has recorded about 15.4 microradians of inflation since the end of episode 53 exceeding the 13.9 microradians of deflationary tilt measured by UWD during episode 53.

During inter-episode pauses, the sulfur dioxide (SO₂) emission rate from the summit typically varies between 1,000 to 5,000 tonnes per day. Winds are currently from the northeast blowing the gas plume to the southwest. Forecasts suggest that these conditions will hold throughout the day at both higher and lower altitudes.

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 precursory overflows and inflation well in excess of episode 53 deflation indicate that episode 54 lava fountaining onset is likely today, if the activity follows the pattern of previous episodes.

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. A collapse pit in the slope behind the south vent formed a new west vent during episode 53. 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 53:

A detailed account of episode 53 is given in the HVO Status Report issued on August 13: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-08-13T11:52:10+00:00

• Episode 53 of the ongoing Halemaʻumaʻu eruption began around 3:45 p.m. HST on August 12 and ended abruptly at 1:23 a.m. HST on August 13, 2026.
• The maximum lava fountain height was approximately 500 feet (150 meters) above ground level from the north vent. The south vent never fountained during this episode but did produce overflows prior to the fountaining episode. A new west vent produced precursory overflows and emitted intermittent flames through most of the eruption. 
• The maximum plume height was approximately 18,000 (5,500 meters) above mean sea level. 

• Tephra fall was restricted mostly to the closed area of Hawaiʻi Volcanoes National Park, southwest of the active Halemaʻumaʻu vents.  

   

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.