USGS Volcanoes: Notices released in the last day.

Slow eruption of lava within the summit crater continues. Minor earthquakes were detected over the past day. No activity was observed in cloudy satellite and webcam images over the past day.  

A field crew working at the volcano has provided several new photos and videos of the lava dome at Great Sitkin availible at https://avo.alaska.edu/volcano/great-sitkin

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.

Low-level earthquake activity continues. Minor steaming was observed from the fumarole zone on the volcano. Nothing noteworthy was observed in satellite data.

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.

Unrest continues with minor seismic activity detected during the past day. No activity was observed in cloudy satellite and web camera views over the past day.  Sulfur dioxide emissions were detected in satellite data.

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. 

Slow eruption of lava within the summit crater continues. Minor earthquakes were detected over the past day. No activity was observed in cloudy satellite and webcam images over the past day.  

A field crew working at the volcano has provided several new photos and videos of the lava dome at Great Sitkin availible at https://avo.alaska.edu/volcano/great-sitkin

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 during the past day. No activity observed in partly cloudy satellite views over the past day. Steam emissions observed in web camera views this morning. Minor sulfur dioxide emissions detected in satellite data.

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. 

Low-level earthquake activity continues. Minor steaming was observed in web camera views of the volcano. 

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 following lava fountaining episode 54 on August 25, 2026. Summit inflation initially resumed after the end of the episode, but deflation began early yesterday and continues at variable rate this morning. Moderate glow and periodic flames have been visible at the north vent, along with occasional weak glow at the west vent. Another lava fountaining episode is likely in the coming weeks, if normal tilt patterns resume. 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 recap of episode 54 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, moderate glow and periodic flames were visible at the moderate vent in Halema’uma’u, along with occasional weak glow at the west vent. The south vent was dark, as it appears to be partially filled in by north vent spatter and tephra erupted during episode 54. Lava flows on the floor of Halemaʻumaʻu crater still exhibited scattered points of incandescence as they cool and solidify after the episode; these points may remain visible for a few more days and nights.

Low-frequency seismic bursts began with the cessation of episode 54 and have continued through this morning, which is typical during the early stages of pauses between eruptive episodes. Two shallow earthquakes have been recorded beneath the summit region over the past 24 hours. 

Summit inflation resumed immediately upon the cessation of lava fountaining, and the Uēkahuna (UWD) tiltmeter recorded a peak of 1.4 microradians of inflation prior to the onset of slow deflation early yesterday. The rate of deflation remained relatively steady until a brief acceleration around 2:00 a.m. HST this morning. As of this update, UWD has lost a total of 0.3 microradians relative to the end of the episode. 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 is likely in the coming weeks. However, the deflationary tilt that has persisted since yesterday morning is evidence that unpredictable, stepwise reinflation will likely continue during this repose period, as it has since episode 51. The current situation where cumulative tilt since the end of the last episode is less than the tilt value at the end of the last episode is unique during this eruption.  More data are needed to assess what this might mean or to model the forecast window if normal patterns of reinflation return.

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.