USGS Volcanoes: Notices released in the last day.

Unrest continues at Mount Spurr volcano, with occasional, small volcanic earthquakes continuing to occur beneath the volcano. No noteworthy activity was seen in mostly clear satellite or webcam images over the last 24 hours. An AVO field crew is at the volcano today performing maintenance and upgrades to the monitoring network. 

Although low-level unrest continues, no changes have been observed in the monitoring data to indicate that the volcano is moving closer to an eruption. Based on previous eruptions, changes from current activity in the earthquakes, ground deformation, summit lake conditions, and fumarolic activity would be expected if magma began to move closer to the surface. Therefore, if an eruption occurred, it would be preceded by additional signals allowing warning.

The volcano is monitored using local seismic, infrasound, web camera, and GNSS (GPS) stations along with regional infrasound, lightning networks, and satellite data.

Lava continues to erupt slowly in the summit crater of Great Sitkin Volcano. Seismicity remains at low levels with occasional small earthquakes detected, including signals possibly caused by small rockfalls from the growing summit lava dome. Webcam and satellite views over the past 24 hours were obscured by clouds.

The current eruption of Great Sitkin Volcano began with a single explosive event in May 2021. The ongoing eruption of lava at the summit began shortly afterward, in July 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks.

Unrest continues at Mount Spurr volcano, with occasional, small volcanic earthquakes continuing to occur beneath the volcano. No noteworthy activity was seen in satellite or webcam images over the last 24 hours.

Although low-level unrest continues, no changes have been observed in the monitoring data to indicate that the volcano is moving closer to an eruption. Based on previous eruptions, changes from current activity in the earthquakes, ground deformation, summit lake conditions, and fumarolic activity would be expected if magma began to move closer to the surface. Therefore, if an eruption occurred, it would be preceded by additional signals allowing warning.

The volcano is monitored using local seismic, infrasound, web camera, and GNSS (GPS) stations along with regional infrasound, lightning networks, and satellite data.

Lava continues to erupt slowly in the summit crater of Great Sitkin Volcano. Seismicity remains at low levels with occasional small earthquakes detected, including signals possibly caused by small rockfalls from the growing summit lava dome. Weakly elevated surface temperatures were seen in one satellite view over the last 24 hours. Webcam views were obscured by clouds.

The current eruption of Great Sitkin Volcano began with a single explosive event in May 2021. The ongoing eruption of lava at the summit began shortly afterward, in July 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data and web cameras, and regional infrasound and lightning networks.

An increase in seismicity at Iliamna that occurred yesterday morning ceased after a few hours, with no surface activity observed. 

The increase, which was marked by frequent small earthquakes, was observed beginning at about 4:30 am AKDT (12:30 UTC) yesterday, June 15, 2025. Initially, the earthquake rate was nearly continuous, with several earthquakes per minute, but then slowed to a rate of about one earthquake per minute, and finally returned to background at about 2:30 pm AKDT (22:30 UTC). 

This seismic activity was likely not caused by volcanic unrest. The seismicity resembled that previously observed preceding large ice and rock avalanches at the volcano. A short (less than one minute) seismic signal at the end of the sequence may have been caused by a small flowage event but no corresponding signal, such as was recorded for past large avalanches, was observed at the Kenai infrasound array. We also have no visual sign of an avalanche, though future high-resolution satellite images may provide more information. 

Iliamna remains at Aviation Color Code and Volcano Alert Level UNASSIGNED/UNASSIGNED because the monitoring network is down to a single station. As snowmelt occurs it is likely that the stations will come back online as power recovers. If outages persist we will conduct site visits to assess possible station damage and make repairs. 

Monitored CALIFORNIA VOLCANOES
Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN

Activity Update: All volcanoes monitored by CalVO show normal background earthquake activity and deformation. Monitored volcanoes include Mount Shasta, Medicine Lake Volcano, Lassen Volcanic Center, Clear Lake Volcanic Field, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.

Past Week Observations for June 09 (0000h PST) to June 15 (2359h PDT):

Typical seismicity was recorded at The Geysers geothermal field south of the Clear Lake Volcanic Field; 115 earthquakes greater than M1 were recorded, with the largest having a magnitude of M2.4.

Two earthquakes greater than M1 were recorded in the Sierra Nevada Block, south of Mammoth Mountain and Long Valley, with the largest having a magnitude of M2.9.

Five earthquakes greater than M1 were recorded in the Coso Volcanic Field, with the largest having a magnitude of M2.5.

Three earthquakes greater than M1 were recorded near the Salton Buttes, with the largest having a magnitude of M1.7.

 

Activity Summary:

The ongoing Halema‘uma‘u eruption is currently paused. Summit inflation continues, along with persistent, low level seismic tremor. Glow was visible overnight at the north and south vents, and spatter was intermittently visible overnight in the north vent. The fountaining phase of episode 26 could begin between June 18 and 20, 2025, based on current rates of summit inflation. This window is subject to change depending on changes in the rate of inflationary tilt.  The fountaining phase could be preceded by hours to days of precursory gas-pistoning activity. 

Fountaining episodes have occurred approximately once per week since the start of the eruption on December 23, 2024. All eruptive activity remains within Hawaiʻi Volcanoes National Park. No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone. Current hazards include ongoing volcanic gas emissions and potential remobilization volcanic glass (Pele’s hair) and tephra deposited during past episodes in the Kīlauea summit region of Hawaiʻi Volcanoes National Park and nearby communities.

Summit Observations:

Overnight, incandescence at both the north and south vents in Halemaʻumaʻu was visible in the V3cam. Intermittent spattering was also visible within the north vent, indicating that magma remains close to the surface within the vent. Degassing also continues from both the north and south vents. 

The average sulfur dioxide (SO₂) emission rate during inter-episode pauses, such as the ongoing pause, is typically around 1,200 tonnes per day (t/d).

Summit tiltmeters have continued to record inflationary tilt following the end of episode 25. A tiltmeter near Uēkahuna (UWD) has recovered about 11.5 microradians of inflationary tilt since the end of episode 25. 

Strands of volcanic glass known as Pele’s hair are present throughout the summit area of Hawaiʻi Volcanoes National Park and surrounding communities and can be remobilized by wind.

• 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 are available here: Kīlauea Volcano, Hawaii (West Halemaʻumaʻu crater) v1cam, Kīlauea Volcano, Hawaii (East Halemaʻumaʻu crater) v2cam, and Kīlauea volcano, Hawaii (South Halemaʻumaʻu crater) v3 cam
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams 

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. Sulfur dioxide (SO₂) emissions from the East Rift Zone remain below the detection limit.

Analysis: 

Tiltmeter UWD, near Uēkahuna, has recovered about 11.5 microradians of inflationary tilt since the end of episode 25 and a tiltmeter near Sandhill (SDH) has recovered 8.5 microradians. As a result, the forecast window for the start of episode 26 fountaining is currently between Wednesday, June 18 and Friday, June 20. This window is subject to change depending on changes in the rate of inflationary tilt. The fountaining phase of past episodes has been preceded by hours to days of gas-pistoning activity, which could also occur prior to episode 26. During gas-pistoning events, gas accumulation causes lava to intermittently rise within one or both vents, with resulting spattering and lava flows onto the crater floor.  

The current eruption has been characterized by episodic fountaining not seen in any eruptions since the 1983–86 episodic fountains at the beginning of the Puʻuʻōʻō eruption. Fountains and lava flows have erupted from two vents within Halema'um'a'u crater that we refer to as the north vent and south vent. Each of the previous fountaining episodes lasted from a few hours to over a week and have been accompanied by strong deflation of the summit region. Pauses between the fountaining episodes have been marked by an immediate change from deflation to inflation as the magma chamber recharges and repressurizes. Lava fountaining episodes have occurred approximately once per week since the start of the eruption. 

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 Hawaiʻi Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H₂O), carbon dioxide (CO₂), and sulfur dioxide (SO₂)—are the primary 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/

Additional hazards include Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity. Volcanic fragments can fall on the ground within a few hundred yards (meters) of the eruptive vent(s), or downwind of the vent(s). Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are 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 current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair forms, 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.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.

For discussion of Kīlauea hazards, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.