USGS Volcano Notice - DOI-USGS-HVO-2026-01-16T17:09:47+00:00

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 4 PM HST yesterday.  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 continues to show spikes every 5-10 minutes, consistent with gas-pistoning within the vents. Incandescence from the episode 40 lava flow has almost entirely subsided.

A fourth earthquake swarm was recorded yesterday, January 15, just after 4 PM HST, spread broadly beneath the east side of Halemaʻumaʻu crater and the south caldera. Activity died down to a low level within 20 minutes and tiltmeters recorded only a slight decrease in inflationary tilt. All of the detected earthquakes have been less than magnitude-2, with most being magnitude-1 or smaller.  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 Statment 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 8.8 microradians of inflationary tilt, with an increase of 2.0 microradians in the past 24 hours. This rate of increase is similar to reinflation rates seen in the past, despite the tilt perturbations seen during the recent earthquake swarms.

The summit SO₂ emission rate was measured yesterday, 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.