USGS Volcanoes: Notices released in the last day.

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. A number of small local earthquakes were detected. Clouds obscured satellite and webcam images.

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.

Shishaldin Volcano continues to experience unrest with numerous small earthquakes detected over the past day. Steam emissions were observed 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 lighting data, and satellite images to detect eruptions. 

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.

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 January 23 and 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 several brief instances of weak spattering from the north vent. Constant low-level tremor continues this morning.

Two multi-hour periods of elevated micro-seismicity occurred over the past day, the first starting around 6:00 p.m. HST yesterday evening and the second starting around 2:00 a.m. HST this morning. However, neither period saw earthquake activity as strong as the swarms earlier this week and only four earthquakes were large enough (all were about magnitude 1) to be located over the past 24 hours. Earthquake locations continue to be spread fairly widely beneath the southeast part of Halemaʻumaʻu, 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: USGS Volcano Notice - DOI-USGS-HVO-2026-01-15T06:34:34+00:00.

Since the end of episode 40, the UWD tiltmeter has recorded 16.2 microradians of inflationary tilt, with net 1.8 microradians of inflation over the past 24 hours. Both periods of elevated seismicity over the past day coincided with brief deflationary tilt of about 0.5 microradians each. 

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. Overnight, UWD tilt recorded rapid inflation of the summit despite the cumulative tilt drop of 1 microradian associated with the swarms of micro-seismicity.  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 the appearance of spattering 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.

A possible detection from the direction of Ahyi was observed on the Wake Island North Hydroacoustic Array on the morning of Jan 17 UTC. No signs of eruptive activity were observed in satellite data, including a cloud-free high-resolution WorldView-3 image on Jan 17 UTC. The last visible plume of discolored seawater was observed on Jan 9.

There are no local monitoring stations near Ahyi seamount, which limits our ability to detect and characterize volcanic unrest there. We will continue to monitor satellite and distal hydroacoustic data for additional evidence for, or escalation of, volcanic activity.

NORTHERN MARIANAS VOLCANOES
No definitive signs of unrest were detected at any other 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.