USGS Volcanoes: Notices released in the last day.

The Aviation Color Code and Alert level remain at UNASSIGNED for Aniakchak Volcano. The status of the volcano was moved from GREEN/NORMAL to UNASSIGNED/UNASSIGNED on December 23, 2025 due to a lack of data received from Aniakchak seismic stations following a power outage at the Port Heiden Receive Facility. Some preliminary repairs to the power system have since been completed at the receive facility and the Alaska Volcano Observatory began to receive data on February 5 from the geophysical network located on Aniakchak volcano.  Data acquisition remains stable since the repairs, but the status of the volcano will remain at UNASSIGNED until permanent repairs can be made to systems to insure reliable connectivity. 

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Seismic activity continues at a very low level. Elevated surface temperatures were observed in satellite imagery from yesterday afternoon.  

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, webcams, and regional infrasound and lightning networks.

Unrest continues at Shishaldin Volcano. Seismic activity remains elevated, with numerous small earthquakes and periods of volcanic tremor being observed. Satellite and webcam views of the volcano were obscured by clouds. 

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. 

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. Episode 42 ended February 15 at 11:38 p.m. HST. Preliminary models suggest the likely forecast window for the onset of episode 43 lava fountaining is March 2-14, at least two to three weeks away.

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

A recap of episode 42 can be found in this Status Report.

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

Summit Observations:                                                                                                                        

Moderate to bright glow from both vents was visible through the night. At the time of this report, both vents are quiet and emitting robust degassing plumes. Seismic tremor continues during the current pause, with intermittent bursts of slightly stronger tremor that occasionally correlate with brighter glow from one or both of the vents. There were no earthquakes located across the summit region during the past day.

Incandescence of flows on the floor of Halemaʻumaʻu crater was greatly reduced last night compared to the previous night. Lava emplaced around and above the vents continued to move downslope into the crater but at a much lower rate. Incandescence on the crater floor may remain for several days.

The UWD tiltmeter has recorded a total recovery of nearly 9.2 microradians of inflationary tilt since the end of episode 42, with 1.6 microradians of that in the past 24 hours.

Plume geometry and weather prevented measurements of sulfur dioxide (SO₂) emission rate during episode 42's fountaining, but the emissions were likely in the range of 100,000 t/d, similar to during previous episodes. During pauses, like the current conditions, the SO₂ emission rate from the summit has varied within a typical range of 1,000 to 5,000 tonnes of SO2 per day. This morning, webcams show that the plume from the summit vents is being carried to the southwest.
 

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 tilt and strong glow from both vents indicate that another fountaining episode is likely. Preliminary models suggest the forecast window for the start of episode 43 is likely between March 2 and March 14.  Additional data are needed to narrow down the forecast window.

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:

A recap of episode 42 can be found in this Status Report.

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
• Note: The V3 camera is experiencing data issues and we have ordered a new camera to replace it following episode 42.
• 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 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.