USGS Volcanoes: Notices released in the last day.

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. A few small local earthquakes were detected over the past day. Southward motion of the south flank of the lava dome and associated local rockfalls were observed in satellite radar imagery. Weak steaming from the active lava dome was also observed in otherwise mostly cloudy satellite imagery. Webcam views were obscured by clouds. 

The current lava eruption began in July 2021 and since then has 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 and webcams, and regional infrasound and lightning networks.

Shishaldin Volcano continues to experience unrest with frequent small earthquakes detected over the past day. Weakly elevated surface temperatures and steaming were observed in clear satellite and webcam views of the summit. 

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 lighting data, and satellite images to detect eruptions. 

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 January 19 (0000h PST) to January 25 (2359h PST):

Typical seismicity was recorded at The Geysers geothermal field south of the Clear Lake Volcanic Field; 114 earthquakes greater than M1 were recorded, with the largest having a magnitude of M2.5.

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 M1.4.

Two earthquakes greater than M1 were recorded in the Coso Volcanic Field, with the largest having a magnitude of M1.6.

One earthquake greater than M1 was recorded near the Salton Buttes, with a magnitude of M1.7.
 

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. Intermittent glow was visible overnight from both vents. Summit inflation and seismic tremor continued over the past 24 hours. Based on preliminary data, the current forecast for the onset of episode 42 lava fountaining is between February 9 and 20.  No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

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

Summit Observations:                                                                                                                        

Intermittent moderate glow from the south vent and intermittent minor glow from the north vent was visible on webcams overnight.

The Uēkahuna tiltmeter (UWD) has recorded 9 microradians of inflation since the end of episode 41, including 1 microradian of invlation in the past 24 hours.

Seismic tremor continued in the past 24 hours with 2-3 pulses of increased tremor about every ten minutes. About 3 earthquakes were located beneath Kīlaueaʻs summit in the past 24 hours.

The sulfur dioxide (SO₂) emission rate from the summit was last measured on January 14 at 1,550 tonnes per day, which is within the typical range of 1,000 to 5,000 tonnes of SO₂ per day observed during previous eruptive pauses. This is considerably lower than rates observed during lava fountaining episodes.

Rift Zone Observations:

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

Analysis:

The rapid rebound of inflationary tilt, glow from the vents, and presence of low-level volcanic tremor after episode 41 indicate that another lava fountaining episode is likely. Based on preliminary data, the current forecast for the onset of episode 42 lava fountaining is between February 10 to 20, 2026, but more time and data are needed for a more accurate forecast.

Kīlauea has been erupting episodically since December 23, 2024, primarily from two vents (north and south) in Halema‘uma‘u. Eruptive episodes, which generally last for less than 12 hours, are separated by pauses that can be as long as over two 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

Recap of episode 41:

Episode 41 of the ongoing Halemaʻumaʻu eruption began around 11:10 a.m. HST on January 24, 2026, marked by a sharp increase in tremor and deflationary tilt at recorded at the Uēkahuna tiltmeter (UWD). North and south vent fountain heights peaked just after 12:30 p.m., with maximum fountain heights estimated around 460 to 480 m (1500 to 1575 feet). Fountains from both vents remained relatively close in size during the eruption but began slowly declining after 1:00 p.m. HST. Widespread tephra fall was reported in the National Park and surrounding areas including communities to the north of the National Park. Fine ash was reported falling as far away as Hilo and coastal areas of Puna. 

Episode 41 lava fountaining from the north vent stopped at approximately 7:26 p.m. HST on January 24. The south vent dropped rapidly, then jetted back up for 30 seconds just prior to the eruption ceasing at 7:29 p.m. HST January 24. Episode 41 ended after 8 hours and 18 minutes with both the north and south vents active for most of the eruption. The highest peak or instantaneous effusion rate of 1050 cubic yards (800 cubic meters) per second occurred just after 12:30 p.m. HST on January 24. Episode 41 ended with an average effusion rate of 470 cubic yards per second (360 cubic meters per second). An estimated 14 million cubic yards (11 million cubic meters) of lava erupted and covered about 80-85% of Halemaʻumaʻu crater floor. The Uēkahuna tiltmeter (UWD) recorded about 31 microradians of deflationary tilt during episode 41. 

Tephra was reported in communities including Volcano Village, Mauna Loa Estates, Ohia Estates, Mountain View, Fern Acres, Kurtistown, Ainaloa Estates, Hilo, Hawaiian Paradise Parks, Hawaiian Beaches, and Pahoa. Tephra fall in more distant communities (Mountain View, Fern Acres, Kurtistown, Ainaloa Estates, Hilo, Hawaiian Paradise Parks, Hawaiian Beaches, and Pahoa) is fine-grained ash and Pele's hair. Falling tephra can pose a health hazard and may contaminate catchment water supplies.  See this State of Hawaiʻi Department of Health release for more information. https://governor.hawaii.gov/newsroom/news-release-doh-urges-caution-with-elevated-volcanic-gas-emissions/. 

Resources:

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 fountains and eruptive activity can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages 
• Three Kīlauea summit livestream videos 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 polution) 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, and reticulite—are created by the lava fountains. 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 and eye irritation. More information is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf. Close to the vents, the tephra material on the crater rim is prone to cracking, slumping, and small landslides that sometimes expose hot and molten material within. 
• Lava flows: on the floor of Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera, remain hot and may slowly move in the days immediately following an eruptive episode. 

Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. 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.