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. Weakly elevated surface temperatures were observed in partly cloudy satellite imagery as well as snow-free regions of the lava flow where recent rockfalls have have been observed.

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 ground-hugging 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 weakly elevated surface temperatures 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.

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 09 (0000h PDT) to March 15 (2359h PDT):

Typical seismicity was recorded at The Geysers geothermal field south of the Clear Lake Volcanic Field; 101 earthquakes greater than M1 were recorded, with the largest having a magnitude of M3.2.

Two earthquakes greater than M1 were recorded in the Long Valley Caldera, with the largest having a magnitude of M2.1.

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 M1.5.

One earthquake greater than M1 was recorded in the Coso Volcanic Field, with a magnitude of M1.4.

One earthquake greater than M1 was recorded near the Salton Buttes, with a magnitude of M2.2.
 

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. The summit is currently inflating, intermittent glow was visible, and tremor continues. Preliminary models suggest the forecast window for the onset of episode 44 lava fountaining is March 30 to April 8.

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

High winds and heavy rains have impacted our monitoring network and caused on-going instrument outages around the summit. Aberrant signals are also observed during storm conditions at other data 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:                                                                                                                       

The V3 webcam had limited visibility but glow was observed in the south vent especially just before dawn. At this time, both vents are quiet and emitting plumes of gas when visible through the rain and clouds. Abundant steam is rising from the hot lava flows within Halemaʻumaʻu crater.

Seismic tremor continues with tremor bursts every 5-10 minutes. Tremor bursts correlate with peak F1 thermal camera temperatures of the south vent suggesting gas pistoning continues within the vent. There were four earthquakes recorded near the summit region during the past day, all of which were under M1.6 and had no effect on Kilauea volcanic activity.

The UWD tiltmeter lost connection on March 15, around 4:19 p.m. HST, due to heavy weather conditions. Prior to shutting down, the last recorded data at UWD began showing signs of slight inflation. Other tiltmeters located around the summit also show inflation over the past 24 hours. The SDH tiltmeter, which is the next closest station to the crater vents, has measured ~0.25 microradians of inflation in the past day.

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. The National Weather Service forecast for the Kīlauea summit region for today indicates winds from the east-southeast at 7-18 mph with gusts up to 25 mph. Cloudy skies and isolated showers will likely continue throughout the 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 the fountaining phase coupled with continued tremor and visible glow from the vents suggest that another fountaining episode is likely. Ongoing oscillations between inflation and deflation measured at the summit may impact the time to the next fountaining episode. Weather related issues and loss of the UWD tiltmeter have complicated modeling for this episode. Preliminary models indicate that episode 44 fountains are likely to start between March 30 and April 8.

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 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.