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 satellite and 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. 

Activity Update: All volcanoes in the Cascade Range of Oregon and Washington are at normal background activity levels. These include Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams in Washington State and Mount Hood, Mount Jefferson, Three Sisters, Newberry, and Crater Lake in Oregon.

Past Week Observations: During the past week, small earthquakes were detected at Mount Rainier, Mount St. Helens, and Mount Hood. All monitoring data are consistent with background activity levels in the Cascade Range.

On Thursday, March 12, 5:16 p.m. HST, a magnitude-4.4 earthquake occurred 8 mi (13 km) east-southeast of Pāhala on the Island of Hawaiʻi at a depth of 18 mi (29 km) below sea level. The earthquake had no apparent impact on either Mauna Loa or Kīlauea volcanoes.  

This earthquake is part of the seismic swarm under the Pāhala area, which has been going on since 2019. Earthquakes in this region have been observed at least as far back as the 1960s. See https://www.usgs.gov/news/volcano-watch-why-do-so-many-deep-earthquakes-happen-around-pahala for more information. 

The USGS Hawaiian Volcano Observatory continues to monitor Hawaiian volcanoes for any changes. 

EARTHQUAKE DESCRIPTION 

• Magnitude: 4.4 
• Date and Time: March 12, 2026, at 5:16 p.m. HST 
• Location: 8 mi (13 km) ESE of Pāhala 
• Depth: 18 mi (29 km) below sea level 
• Aftershocks are possible in the coming days to weeks 

EARTHQUAKE INTENSITY AND AFFECTED AREA 

• Potential Damage: No damage to buildings or infrastructure expected based on earthquake intensity 
• Maximum Intensity, Modified Mercalli Scale (https://www.usgs.gov/natural-hazards/earthquake-hazards/science/modified-mercalli-intensity-scale) 
• Community-reported: IV - light shaking 
• Instrument-derived: IV - light shaking 
• Felt Reports: More than 155 within the first half hour (http://earthquake.usgs.gov/dyfi/) 
• Felt Area: Around the Island of Hawaiʻi 
• Visit NOAA’s Tsunami Warning Center website for updated information: https://www.tsunami.gov/ 

EARTHQUAKE MAPS AND ADDITIONAL INFORMATION 

• USGS National Earthquake Information Center Maps and Reports for this Event: https://earthquake.usgs.gov/earthquakes/eventpage/hv74916907 
• USGS-HVO Interactive Earthquake Map of Hawaiʻi: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/earthquakes 

Activity Summary:

The Halemaʻumaʻu eruption of Kīlauea is paused. Incandescence was observed from both vents overnight, inflation and tremor continue. Preliminary models suggest the forecast window for the onset of episode 44 lava fountaining is March 28 to April 12.

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

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

See the citizen reported tephra fall map for episode 43 here: Hawaiian Volcano Observatory | Tephra Reports Map

NOTE: Crews accessed the V1 camera but determined it suffered internal damage and will need to be replaced.  Sound is still active on the camera.

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

Summit Observations:                                                                                                                        

Intermittent, moderate glow was persistent from the south vent last night, but weaker and more infrequent from the north vent. At this time, both vents are quiet and emitting plumes of gas. 

Incandescence of flows on the floor of Halemaʻumaʻu crater was greatly reduced last night compared to the previous night.  A bright overturn of the small persistent depression just east of the vents occurred overnight. Flows could still be detected creeping near the vents. Incandescence on the crater floor may remain for several days. Flows around the vent may also continue to be incandescent and move downslope during this time.

Seismic tremor continues during the current pause with bursts of tremor every three to five minutes typically associated with gas pistoning within the vent.  There were no recorded earthquakes located across the summit region during the past day.

The UWD tiltmeter has recorded a total recovery of nearly 7.1 microradians of inflationary tilt since the end of episode 43, with 3.3 microradians of that 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. This morning, webcams show that the plume from the summit vents is being carried to the northeast. The National Weather Service forecast for the Kīlauea summit region for today indicates winds from the southwest at 11 to 16 mph, with gusts as high as 22 mph.

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 and strong glow from both vents suggest that another fountaining episode is likely. Preliminary models indicate that episode 44 fountains are likely to start between March 28 and April 12. 

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.

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.