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. Minor growth of the lava dome to the southwest, rockfalls, steaming, and elevated surface temperatures from the warm, snow-free lava dome surfaces were observed in clear 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 steam plume was seen in clear webcam imagery and sulfur dioxide gas was detected in satellite data.  

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 was detected in satellite data. No other activity was observed in other satellite views.  

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.

Correction:  The previous report mistakenly raised to color code to Orange and Alert Level to Watch. The correct Aviation color code is Yellow and the Alert level is Advisory.  

A substantial increase in seismicity was detected at the Atka volcano complex between 4:20-4:30 PM AKST March 14 (00:20-00:30 March 15 UTC).  Small earthquakes and weak tremor have been observed over the past week and elevated levels of sulfur dioxide gas has been detected in satellite data. This activity increases the likelihood of explosive events at the one of the volcanoes within the Atka volcano complex, most likely Korovin. The Alaska Volcano Observatory is increasing the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY.  

A substantial increase in seismicity was detected at the Atka volcano complex between 4:20-4:30 PM AKST March 14 (00:20-00:30 March 15 UTC).  Small earthquakes and weak tremor have been observed over the past week and elevated levels of sulfur dioxide gas has been detected in satellite data. This activity increases the likelihood of explosive events at the one of the volcanoes within the Atka volcano complex, most likely Korovin. The Alaska Volcano Observatory is increasing the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY.  

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. The summit is currently deflating, but 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 (up to 20 inches) are impacting our monitoring network and can cause aberrant signals.

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

Correction: Yesterday's Update reported that the south fountain reached a maximum sustained height of 1540 feet, the correct number was 1770 feet (540 meters); the north fountain reached over 1400 feet (430 meters) in height, both records for this eruption. Final measurements are made from trigonometrically corrected, high-resolution cameras that have to be manually downloaded after the eruption.

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:                                                                                                                        

Webcams overnight had zero visibility and vent glow could not be determined. 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 bursts of tremor every 10-20 minutes. There were no recorded earthquakes located across the summit region during the past day. 

The UWD tiltmeter began recording deflation just after noon yesterday. This morning UWD shows 9.5 microradians of inflation since the end of episode 43, a loss of 1.5 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. The National Weather Service forecast for the Kīlauea summit region for today indicates winds from the southwest winds ranging from 23 to 29 mph with gusts up to 41 mph along with heavy rain over the next several days.

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 suggest that another fountaining episode is likely. The ongoing deflation may increase the time to the next fountaining episode if it continues. 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-pist…

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.