USGS Volcanoes: Notices released in the last day.

Lava continues to erupt slowly within the summit crater. Minor earthquakes were detected in the past day. Clouds obscured webcam and satellite views of the volcano.

The current eruption began in July 2021. Since then, lava flows have filled most of the summit crater and advanced into valleys below. There have been no explosions at Great Sitkin Volcano since an event in May 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data, webcams, and regional infrasound and lightning networks.

Unrest continues, with minor seismic activity detected in the past day. Partly cloudy webcam views show weak steaming from the summit. Satellite imagery shows that the summit has a weak thermal anomaly likely due to the steam plume observed in webcams and favorable atmospheric conditions.

Local seismic and infrasound sensors, web cameras, and a geodetic network are used to monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lightning data, and satellite images to detect eruptions. 

Seismic activity over the past day was quiet. Cloudy weather obscured satellite views.

A new temporary monitoring station was installed recently near Mount Kupreanof and is providing seismic data, infrasound data, gas measurements, and web camera images on an intermittent basis. This is by design to conserve battery power, but the frequency of data acquisition can be increased if activity warrants. The closest functioning seismometers that provide continuous data are approximately 10 miles (16 km) to the northeast of the volcano as part of the Mount Veniaminof network. Mount Kupreanof is also monitored by satellite data, remote infrasound and lightning networks, and visual observations from pilots and mariners passing by the volcano.

Overview:

The summit eruption of Kīlauea in Halemaʻumaʻu is paused. Weak to moderate glow was nearly continuously visible from the north vent until about 11 p.m. HST when it was obscured by heavy rain and steam. Summit reinflation has been very irregular since lava fountaining episode 54 on August 25. The deflation that began Thursday morning transitioned into a period of little or no change on Friday and into rapid inflation for the past 24 hours. The current rapid summit inflation is similar to what preceded the onset of episodes 51-54. A forecast window of September 7-10 is likely for the next episode if inflation follows the prior patterns.

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 weak to moderate glow nearly continuously from the Halemaʻumaʻu north vent until about 11 p.m. HST when it was obscured by heavy rain and steam. No flames were observed.

Low level tremor continues across the summit. No significant tremor bursts were recorded by summit seismometers over the past 24 hours. One small earthquake was recorded beneath the summit region over the past 24 hours.

Summit reinflation has been very unsteady since lava fountaining episode 54 on August 25. On Thursday, tilt recorded on UWD had declined from 7.8 to 6.2 microradians relative to the end of lava fountaining episode 54. Summit inflation then stalled with the UWD tiltmeter reading 6 microradians from Friday morning to Saturday morning when rapid summit inflation began. The summit inflated about  4 microradians, as recorded on the UWD tiltmeter, over the past 24 hours. The summit continues to rapidly inflate and has recovered about 10 microradians of the 12.7 microradians lost 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 lava fountaining episode 54 and continued seismic tremor bursts from the Halemaʻumaʻu eruptive vents indicate that another lava fountaining episode may occur in the coming weeks. Reinflation has been slow and irregular, having been interrupted by multiple deflations of varying magnitude and duration. After inflating over 4 microradians from September 1-3, the summit deflated from Thursday to Friday (September 3-4) morning, after which it stalled for another day. Rapid summit inflation began around 10 a.m. HST on Saturday, September 5 and gained about 4 microradians in the past 24 hours. The north vent continues to glow, weather permitting, suggesting that magma has returned to higher levels in the vent conduit. The recent rapid summit inflation appears to be following a pattern similar to the period immediately preceding the onset of the last 4 fountain episodes (51-54), suggesting the onset of episode 55 may occur within the next 1-3 days if inflation continues at this rate. Episode 55 activity is likely to start Monday if the current inflation rate of 4 microradians a day (UWD tilt) is sustained. If the inflation rate slows or if there are minor periods of stalling or deflation, the onset would be more likely on Tuesday or Wednesday, September 8 to 9. Should another significant deflation occur, it could push the forecast for the potential onset of episode 55 fountains back to Thursday to Sunday, September 10 to 13.

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.