USGS Volcanoes: Notices released in the last day.

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Seismic activity was elevated with small earthquakes and rockfalls detected over the past day. Moderately elevated surface temperatures and snow-free areas of the active lava flow were observed in partly cloudy satellite imagery.

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 and infrasound activity remains elevated, with numerous small earthquakes, seismic tremor, and infrasound detections observed over the past day. A weak sulfur dioxide (SO2) plume was observed trending southward in clear satellite imagery. A small steam plume was seen in clear webcam imagery.  

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 unrest continues at the Atka volcanic complex with weak to moderate tremor and numerous small earthquakes observed in seismic data. Sulfur dioxide gas and moderately elevated surface temperatures from the persistent summit lake were detected in satellite data.

The Atka volcanic complex includes several vents, including Korovin Volcano, Mount Kliuchef and Sarichef Volcano. Korovin has been the site of most historical eruptions that typically produce minor amounts of ash and occasional but small lava flows. The Atka volcanic complex is monitored by local seismic and infrasound sensors and webcam, satellite data, and regional lightning detection instruments.

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. The summit is currently inflating slowly, occasional glow was visible from the south vent and gas-pistoning continues. The preliminary forecast window for the onset of episode 44 lava fountaining is April 1 to April 10.

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

High winds and heavy rain have impacted our monitoring network, causing ongoing instrument outages around the summit. A new power outage affecting the telecommunications chain HVO uses to transmit data from monitoring stations occurred this morning at approximately 6:30 a.m. HST but was restored around 9:15 a.m. HST. This outage affected multiple seismic, camera, GPS, and tilt stations.

A summary of episode 43 can be found in this Status Report.

NOTE: The V2 camera went offline due to a power outage, the V1 camera remains damaged from episode 43.

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

Summit Observations:                                                                                                                       

Overnight, intermittent glow was observed at the south vent via the V3 webcam. Currently, both vents are quiet and emitting gas plumes, while abundant steam rises from cooling lava flows from episode 43 within Halemaʻumaʻu crater.

Seismic tremor has decreased overall, though tremor bursts persist at intervals of 5–10 minutes. These bursts correlate with peak temperatures recorded by the F1 thermal camera at the south vent, consistent with ongoing gas pistoning within the vent. One earthquake was recorded at the summit during the past day.

Summit tiltmeters UWD, SDH, and SMC continue to record slow inflation tha past few days.  UWD is estimated to have gained approximately 11.6 microradians of tilt since the end of episode 43 with an estimated gain of 0.4 microradians in the past 24 hours.  

During eruptive 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.

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:

Rapid rebound of tilt following episode 43 fountaining, continued tremor, and visible glow from the vents suggest that another fountaining episode is likely. Summit inflation remains slow compared to other episodes of repose and is complicated by weather signals and loss of data during power outages. Preliminary models indicate that episode 44 fountains are likely to start between April 1 and April 10.

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Fountaining episodes, which generally last for less than 12 hours, are separated by pauses that can be longer than 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 43:

Episode 43 ended at 6:21 p.m. HST after fountaining for just over 9 hours from both vents and sending tephra into surrounding communities. A complete summary of activity can be found here. 

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 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.

NOTE: Volcano Observatory Notice for Aviation (VONA) and associated Volcano Activity Notices (VAN) are now required to be repeated every day for volcanoes at RED, every week for volcanoes at ORANGE, and every two weeks for volcanoes at YELLOW.

The Halemaʻumaʻu eruption of Kīlauea volcano is currently paused, current forecast for episode 44 fountaining onset is April 1-10. Episode 43 fountaining ended at 6:12 p.m. HST on Tuesday March 10, 2026.

• All eruptive vents and lava flows are confined to Halemaʻumaʻu crater within Hawaiʻi Volcanoes National Park. Tephra fall from volcanic ash clouds is greatest within 3 miles (5 km) of the vents, lighter ash and Peleʻs Hair may stay suspended for large distances from the vents.
• Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information 
• Three Kīlauea summit livestream videos are available here: https://www.youtube.com/@usgs/streams 
• Additional short updates shared during the episode can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages 

NORTHERN MARIANAS VOLCANOES
No definitive signs of unrest were detected at any Northern Mariana Island volcanoes during the past week. 

Monitoring of Northern Mariana Islands Volcanoes

Northern Mariana Island volcanoes are monitored using seismo-acoustic sensors on Saipan, and by examining satellite imagery. We also use distant seismic stations in Guam and Chichijima, Japan, and hydroacoustic data from Wake Island, when available. 

This level of monitoring can detect significant volcanic activity in the CNMI but cannot provide advanced warning of eruptions.

Due to a lack of geophysical monitoring on any of the volcanic islands, the following volcanoes have alert levels of UNASSIGNED: Anatahan, Sarigan, Farallon de Pajaros, Supply Reef, Maug, Asuncion, Agrigan, Pagan, Almagan, and Guguan.