USGS Volcanoes: Notices released in the last day.

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Clouds obscured views of the volcano in satellite and webcam images. Little earthquake activity was detected. 

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 and webcams, and regional infrasound and lightning networks.

No significant earthquake activity was detected over the last day. Satellite and webcam images showed no evidence for surface changes or activity.

Pavlof Volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks. 

Shishaldin Volcano continues to experience unrest with numerous small earthquakes detected over the past day. Clouds obscured webcam and satellite images. No surface changes were seen in the summit crater in a new satellite radar image. 

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 lighting data, and satellite images to detect eruptions. 

Lava continues to slowly erupt within the summit crater at Great Sitkin Volcano. Satellite data on January 13 confirmed that the lava dome is slowly inflating towards the southeast, with minor rockfalls occurring along this growing edge. All week clouds obscured images of the volcano. Seismic activity remains low, with only occasional small earthquakes and rockfalls detected.

The current eruption of lava began in July 2021 and 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 and web cameras, and regional infrasound and lightning networks.

A notable increase in the rate of long-period earthquakes started on January 14 at 12:45 am AKST (09:45 UTC). This activity prompted an increase of the Aviation Color Code and Volcano Alert Level to YELLOW/ADVISORY. Clear satellite and webcam images the following days did not show any evidence for surface changes or activity. The earthquake activity has also decreased to background levels over the last two days.

Increases in this type of earthquake activity in the past have preceded eruptions, but also have ended without an eruption occurring. Eruptions at Pavlof Volcano have also occurred with little or no precursor activity.

The Alaska Volcano Observatory will continue to closely monitor Pavlof Volcano data to confirm if the period of elevated activity has ended. The volcano is monitored by local seismic and infrasound sensors, satellite data, web cameras, and regional infrasound and lightning networks. 

Signs of volcanic unrest at Shishaldin Volcano continued this week. Web camera images, when clear, showed a plume of gas rising from the summit crater. Low-level seismic activity has persisted, with small earthquakes occurring frequently. Infrasound signals, likely caused by gas bubbles bursting deep within the volcanic vent, were also detected throughout the week when the conditions were not too windy. At this time, there is no evidence of lava at the surface.

Shishaldin Volcano is monitored by local seismic and infrasound sensors, web cameras, and a telemetered geodetic network. In addition to the local monitoring network, the Alaska Volcano Observatory uses nearby geophysical networks, regional infrasound and lighting data, and satellite data to monitor the volcano.

Activity Summary:

The eruption of Halemaʻumaʻu at the summit of Kīlauea is paused. The current forecast for the onset of the next lava fountaining episode is currently between January 20 to 25, 2026 based on current inflation models. Sporadic earthquake swarm activity continues at the summit, with the most recent occurring just after 5:07 AM HST this morning.  No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

Significant changes in activity between updates are posted here: HVO - Observatory Messages | U.S. Geological Survey.

Summit Observations:                                                                                                                        

Overnight webcam views show consistent glow from the south vent and weak sporadic glow from the north vent. Seismic tremor spikes gradually became more ragged yesterday and were replaced by relatively constant tremor before midnight yesterday.  Constant low-level tremor continues this morning.

Small seismic swarms continue at the summit, with one at 4:10 PM HST, January 16th and another this morning at 5:07 AM HST. Both were beneath the southeast part of Halemaʻumaʻu and lasted for 10-20 minutes. While the swarm earthquakes were close in time, the locations were spread fairly widely. There was also a magnitude 2.2 earthquake south of Halemaʻumaʻu at 8:22 AM HST this morning, but it is uncertain if this was related to the earlier activity. All of the detected earthquakes in swarms have been less than magnitude-2, with most being magnitude-1 or smaller and 0.5 to 2 miles (1-3 kilometers) deep.  The swarms are related to migrating magmatic pressure within the summit region but their impact on the next episode of fountaining, if any, is unknown at this time.  See this Information Statement for more details: USGS Volcano Notice - DOI-USGS-HVO-2026-01-15T06:34:34+00:00

Since the end of episode 40, the UWD tiltmeter has recorded 10 microradians of inflationary tilt, with an increase of 1.2 microradians in the past 24 hours. Summit tiltmeters began recording slightly deflationary tilt during the 5 AM HST swarm, before flattening. Other summit swarms have been associated with tilt drops, but the changes during the 5 AM HST swarm were longer and more gradual than previously.

The summit SO₂ emission rate was last measured on January 15, at 1550 tonnes per day, which is within the typical range of 1,000 to 5,000 tonnes of SO₂ per day observed during previous eruptive pauses and is considerably lower than rates observed during fountaining episodes. 

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:

The rapid rebound of inflationary tilt, glow from the vents, and presence of low-level volcanic tremor after episode 40 indicate that another lava fountaining episode is likely. Current rates of reinflation suggest that the next fountaining episode is likely to occur between January 20 and 25. This forecast is subject to change, however, depending on changes in behavior of the volcano. 

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 Last Episode:

Episode 40 was preceded by precursory overflows that began from the south vent on January 8. Over the following days, dome fountains would form in the south vent, feeding overflows that occurred at rates of several per hour, while the north vent produced lava flows less frequently though spattering was often visible within the vent. On the morning of January 12, the north vent appeared to have a constricted opening, generated an arcuate spatter fountain that grew in vigor dramatically at 8:13 a.m. Strong deflation and an increase in tremor marked the start of episode 40 at 8:22 a.m. HST, when north vent fountains reached about 100 feet (30 meters) high. North vent fountain heights peaked at 800 feet (250 meters) high just before 10 a.m. With weak winds, the eruptive plume during episode 40 rose vertically to over 13,000 feet (4000 meters) above ground level before moving to southeast at higher altitudes. Most tephra from episode 40 lava fountains fell west of Halema'uma'u but also occasionally to the northwest and southwest as seen on V1 and V3 cams, with reticulite as large as 2 inches (5 cm) falling at the Uēkahuna Overlook in Hawaiʻi Volcanoes National Park briefly just after 10 a.m. Large whirlwinds or "puahiohio" also occurred during episode 40 and were visible in the livestreams. Episode 40 lava fountaining from the north vent stopped at approximately 7:04 p.m. HST on January 12 after 9.7 hours of sustained fountaining. While the south vent remained open and visibly degassing throughout episode 40, with occasional spatter visible, it did not produce a fountain during this episode. The highest peak or instantaneous effusion rate of 460 cubic yards (350 cubic meters) per second occurred around noon on January 12. Episode 40 ended with an average effusion rate of 250 cubic yards per second (190 cubic meters per second). An estimated 7.1 million cubic yards (5.5 million cubic meters) of lava erupted and covered about 50–60% of Halemaʻumaʻu crater floor. The Uēkahuna tiltmeter (UWD) recorded about 17 microradians of deflationary tilt during episode 40.

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: HVO - Observatory Messages | U.S. Geological Survey. 
• 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 polution) 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, and reticulite—are created by the lava fountains. 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 and eye irritation. More information is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf. 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. 
• Lava flows: on the floor of Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera, remain hot and may slowly move in the days immediately following an eruptive episode. 

Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. 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.