USGS Volcanoes: Notices released in the last day.

Lava continues to slowly erupt within the summit crater at Great Sitkin Volcano. Satellite data on January 18 confirmed this by showing active steaming from the central region of the summit dome. Satellite data on January 22 shows that this area is largely snow-free, while the rest of the dome is covered in snow. Clouds obscured webcam images of the volcano with the exception of January 22. 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. 

Signs of volcanic unrest at Shishaldin Volcano continued this week. Satellite imagery showed barely elevated surface temperatures on January 19, 21, and 23, likely related to the continued gas emissions at the summit and favorable atmospheric conditions. Web camera images, when clear, showed a plume of gas rising from the summit crater. Low-level seismic activity has persisted, with volcanic tremor and 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. 

The period of elevated seismic activity that prompted an increase in Pavlof's alert level on January 14 decreased to background levels this week. As a result, AVO lowered the Aviation Color Code to GREEN and the Volcano Alert Level to NORMAL on January 21. Seismicity remains low and no eruptive activity or unusual surface temperatures have been observed. 

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.

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: Over the past week, small earthquakes were located at Mount St. Helens and Newberry Volcano. Monitoring data are consistent with background activity levels in the Cascade Range.

Activity Summary:

The eruption of Halemaʻumaʻu at the summit of Kīlauea is paused. The forecast for the onset of the next lava fountaining episode is between today January 23 and January 25 based on current inflationary tilt models. Elevated micro-seismicity continues in the summit region. No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

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

Summit Observations:                                                                                                                        

Overnight webcam views of Halemaʻumaʻu showed consistent strong glow from both the north and south vents, with frequent spattering from the north vent. Spattering increased in intensity through the evening culminating in low spatter fountains (about 10 feet or 3 meters high) that fed short overflows from the north vent beginning at 10:40 p.m. HST on January 22.  This was followed by 8 other events until 12:25 a.m. HST this morning, when summit tilt deflated in association with a small earthquake swarm at the summit. Overflows were short travelling about 50 feet (15 meters) from the vent and lasted from 1-5 minutes. Spattering decreased in intensity to pre-overflow levels at the north vent during the rest of the morning. Constant low-level tremor continues this morning.

Four multi-hour periods of elevated micro-seismicity occurred over the past day. The first, and strongest, starting around 12:10 a.m. HST (just after midnight) and followed by smaller swarms beginning at 1:05, 2:10, and 8:35 a.m. HST this morning. However, none of the swarms had earthquake activity anywhere near as strong as the swarms earlier this week. Only five earthquakes were large enough to be located over the past 24 hours (all magnitude 1 or less) beneath the summit. Earthquake locations continue to be spread fairly widely beneath the summit region, as the swarms are related to migrating magmatic pressure within the summit region. Their impact on the next episode of lava fountaining, if any, is unknown at this time. For more information see prior Daily Updates and this Information Statement for more details: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-01-23T03:39:44+00:00.

Since the end of episode 40, the UWD tiltmeter has recorded 16.9 microradians of inflationary tilt, with net 0.7 microradians of inflation over the past 24 hours. The period of elevated seismicity that started just after midnight over the past day coincided with brief deflationary tilt of about 0.8 microradians, with inflation resuming around 3 a.m. HST, after the third period of elevated seismicity. The final weak seismic swarm caused a tiny drop followed by flattening of the tilt at UWD.

The sulfur dioxide (SO₂) emission rate from the summit was last measured on January 14 at 1,550 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. This is considerably lower than rates observed during lava 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 and spatter from the vents, and presence of low-level volcanic tremor after episode 40 indicate that another lava fountaining episode is likely. Everything currently points to resumption of fountaining episodes rather than a change in vent location. The continued repressurization of the Halemaʻumaʻu magma reservoir, persistent glow, and spattering and short-lived lava flows from the north vent all indicate episode 41 fountaining will take place in the next few days. While seismic swarms continue, their intensity is reduced as well as their impact on reinflation of the summit. Models indicate the onset of episode 41 lava fountaining is likely to occur between January 23 and 25. This forecast is subject to change, as always, 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.

Summary

The eruption that began within Halemaʻumaʻu at the summit of Kīlauea volcano on December 23, 2024, continues after 40 lava fountaining episodes. Monitoring data show that the modeled pressurization within the shallow Halemaʻumaʻu magma chamber beneath Kīlauea's summit has been slowly increasing over time and could eventually result in a change to the eruption dynamics. This statement reviews recent observations and summarizes what could be expected next at Kīlauea.

Summary of Recent Activity

The ongoing Kīlauea summit eruption has progressed through 40 episodes of lava fountaining from two vents in Halemaʻumaʻu, separated by pauses in eruptive activity. The increase in eruption rate during lava fountaining rapidly deflates the source—the shallow Halemaʻumaʻu magma chamber. Pauses between lava fountaining episodes are accompanied by reinflation of the shallow Halemaʻumaʻu magma chamber and new episodes usually occur upon full recovery of pressure from what was lost in the previous episode. This consistent repeating pattern has allowed the USGS Hawaiian Volcano Observatory (HVO) to forecast windows of time when new lava fountaining episodes may begin.

Monitoring data from the Kīlauea summit region Global Positioning System (GPS) network is used to generate models of pressurization over time in the two magma chambers below: the shallow Halemaʻumaʻu magma chamber and a deeper magma chamber located beneath the south caldera region. As this eruption has progressed, the modeled amount of pressurization reached in the Halemaʻumaʻu magma chamber before each new lava fountaining episode has slowly increased. Modeled pressurization in the deeper south caldera magma chamber has been slowly decreasing since this eruption began in late 2024. This process is offsetting the increased pressurization that occurred there beginning in October 2023 and continuing to the start of this eruption in December 2024. Increased shallow pressurization may reflect increased magma supply to drive the higher effusion rate of the ongoing eruption, which is about double that of the long-term magma supply rate at Kīlauea.

The magma plumbing system connecting the two eruptive vents in Halemaʻumaʻu to the shallow magma chamber below has been remarkably stable over the past year, with very little earthquake activity. Following the end of episode 40, on the evening of January 12, short-duration swarms of small earthquakes in the region 1.5–4 km (1–2.5 miles) below Halemaʻumaʻu have occurred intermittently, accompanied by abrupt and brief disruptions in the summit’s inflationary tilt trend.

Most of these recent earthquakes have been smaller than magnitude-1.0 and broadly distributed beneath Halemaʻumaʻu and the south caldera region of Kīlauea's summit, suggesting that the stress changes generating the earthquakes are not highly localized. Rather, the swarms appear to be related to a broad change where pressure is accumulating within the summit region. By contrast, when a new eruptive fissure formed in the southwest wall of Halemaʻumaʻu during episode 30 on August 6, 2025, earthquakes were tightly clustered along the path that magma followed to the surface. Additionally, changes in the patterns of summit region ground deformation indicated that magma intruded a new area, which was apparent in the new but short-lived eruptive vent.

The impact of the recent earthquake swarms on the next episode of lava fountaining, if any, is unknown at this time, but there have not been changes in ground deformation patterns to suggest that magma has intruded or is intruding into a new area. Between swarms, Kīlauea's inflationary deformation continues, and the window for the start of episode 41 is currently estimated to be between January 23 and 25 if the inflation rate remains consistent.

• See this Information Statement for more details on the recent earthquake swarms: USGS Volcano Notice - DOI-USGS-HVO-2026-01-15T06:34:34+00:00.
• See the January 22, 2026, “Volcano Watch” article for more information, including a map showing recent earthquake locations and a plot showing Kīlauea summit GPS data: https://www.usgs.gov/observatories/hvo/news/volcano-watch-what-do-small-earthquakes-beneath-kilauea-summit-mean-ongoing.

Possible Outcomes

It is not possible to forecast an exact outcome of this activity. Some potential scenarios in the coming months, based on past events, are described below. Past episodic eruptions of Kīlauea at the start of the 1983 Puʻuʻōʻō and the 1969 Maunaulu eruptions (44 and 12 episodes each) on the East Rift Zone both continued after lava fountaining episodes ended, with fissures opening nearby that erupted more continuous lava flows. Following the end of the 1959 Kīlauea Iki summit eruption (17 episodes), magma eventually moved into the East Rift Zone and erupted in a new location.

• Eruption continues: Magma could continue to erupt from the north and south vents in Halemaʻumaʻu for an unforeseeable amount of time or number of episodes. The vents could break down at some point and begin to erupt lava more continuously.
• New vent forms in summit region or upper Southwest Rift Zone: Magma could form a new shallow pathway toward the surface, potentially resulting in a new vent erupting lava near the existing vents in Halemaʻumaʻu, or nearby within the summit caldera. Intrusive activity in the Southwest Rift Zone in 2024 resulted in numerous new cracks, many of which have been covered with tephra from the recent lava fountains. Given the vent locations in this eruption, and the 2024 intrusive activity, new vents could also form in the upper Southwest Rift Zone. In 1919, a long-lived eruption within Halemaʻumaʻu transitioned into the Southwest Rift Zone, resulting in the Maunaiki eruption that was active for 9 months in the middle portion of the Southwest Rift Zone. In this scenario, we would expect earthquakes with tightly clustered locations, along with changes in the patterns of ground deformation indicative of shallow crack formation, similar to what occurred in the new vent formation during episode 30 on August 6.
• East Rift zone intrusion or eruption: Magma could migrate into East Rift Zone, potentially resulting in an eruption there. However, given the vent locations and summit region deformation patterns, this is the least likely scenario. In this scenario, we would expect increased rates of earthquakes migrating from the summit towards the East Rift Zone along with ground deformation indicative of summit magma chamber deflation.

HVO Actions

Kīlauea's summit region is monitored with a dense network of instruments recording seismic activity, ground deformation, visual and thermal imagery, and volcanic gas emissions. HVO staff closely monitor these various datasets for changes. Kīlauea Daily Updates are published each morning with a summary of the past 24 hours of activity, and we will issue additional messages as needed based on any significant changes detected. Should volcanic activity change significantly, a Volcanic Activity Notice will be issued. HVO is in frequent communication with Hawai‘i Volcanoes National Park and Hawai‘i County Civil Defense to keep them apprised of Kīlauea's activity.

Eruption Resources 

• Eruption resources, including the most recent maps and a timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information.
• Short messages tracking earthquake activity, the evolution of lava fountains, and other 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.
• Most recent Kīlauea message: https://www.usgs.gov/volcanoes/kilauea/volcano-updates.

Continuing 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, and reticulite—are formed by lava fountains. Larger particles fall near the vents while light particles may be wafted greater distances downwind. 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—lava flows remain hot and may slowly move in the days immediately following an eruptive episode.