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. Elevated surface temperatures 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 small steam plume was seen in clear webcam imagery. Satellite images detected sulfur dioxide with this plume drifting to the south.

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 tremor and numerous small earthquakes observed in seismic data. Elevated water temperatures can be seen from the Korovin Volcano crater lake in clear satellite images. 

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.

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 March 16 (0000h PDT) to March 22 (2359h PDT):

Four earthquakes greater than M1 were recorded within the Clear Lake Volcanic Field, with the largest having a magnitude of M2.5.

Typical seismicity was recorded at The Geysers geothermal field south of the Clear Lake Volcanic Field; 131 earthquakes greater than M1 were recorded, with the largest having a magnitude of M3.3.

Three earthquakes greater than M1 were recorded in the Mono-Inyo area north of Long Valley, with the largest having a magnitude of M1.7.

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 M1.6.

Two earthquakes greater than M1 were recorded near the Salton Buttes, with the largest having a magnitude of M1.3.
 

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. The summit is currently inflating slowly; overnight, occasional glow was visible from the south and north vents and gas-pistoning continues.  The forecast window, April 3–13, remains preliminary for the onset of episode 44 lava fountaining due to the lack of consistent data the past two weeks.

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

HVO’s monitoring network is gradually recovering from power and storm related outages.  Yesterday the Uēkahuna (UWD) tiltmeter was revived but no data was recovered so an offset was applied using data from other summit tiltmeters.  Several summit stations, including the SDH tiltmeter, will remain offline until we are able to re-establish access across the deep tephra field south of the caldera.

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

NOTE: The V2 camera is back online following a power outage, and the V1 camera was replaced yesterday after being 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 and north vents. Currently, both vents are emitting gas plumes.

Seismic tremor continues and is punctuated by tremor bursts at intervals of 5–10 minutes. These bursts correlate with glow on the V3 camera and peak temperatures recorded by the F1 thermal camera at the south vent, consistent with ongoing gas-pistoning within the vents. Four earthquakes were recorded at the summit during the past day.

Summit tiltmeters IKI and SMC continue to record slow inflation since the end of episode 43. UWD tiltmeter came back online last night and is also recording slow inflation at the summit. The UWD tiltmeter has recorded an estimated 14.6 microradians of tilt since the end of episode 43.

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 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 3 and April 13. As the summit monitoring network continues to recover and data becomes more consistent, the forecast window should become better defined.

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 on March 10 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.