USGS Volcano Notice - DOI-USGS-HVO-2026-10-01T01:30:09+00:00

Overview:

Over the past 24 hours, north and south vent continued to have intermittent overflows and spattering, with strong glow and flames emitted overnight. As this eruptive activity continued, a shallow intrusion of magma with an east-west orientation occurred within the summit region overnight near the existing eruption location. Intrusive activity was strongest between 8 p.m. H.S.T. last night (September 30, 2026) and this morning around 3 a.m. H.S.T. The intrusive activity was recorded by large rapid displacements on the summit tiltmeters, increased earthquake activity in summit region, and increased tremor. There is no evidence that magma associated with this intrusion erupted in a new location.

Episode 55 fountaining remains a possibility during the ongoing Kīlauea summit eruption. In the past 24 hours, north vent had several overflows that included a small dome fountain, including an overflow that lasted over an hour yesterday afternoon. During the overnight intrusion, north and south vents exhibited strong glow, intermittent spatter, and large flames; west vent also had glow and large flames. North vent also had several large overflows during the intrusion. South vent overflows resumed after intrusive activity ended.

No anomalous seismic activity or deformation has occurred outside of the summit region, and no significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

STATUS REPORT published during intrusive activity: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-10-01T08:14:21+00:00 

STATUS REPORT on changes in activity and implications for this eruption: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-09-15T03:18:09+00:00 

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

Summit Observations:

Overflows from the north vent resumed on the evening of September 22 after about 10 days of quiescence at the vent complex. Overflow activity from the south vent began on September 27. However, the north vent remained dominant until the evening of September 28, when south vent started having short, rapid cycles of overflows and lava drainback that continued through yesterday afternoon. These south vent overflows lasted about 2–5 minutes, with most pauses between each cycle lasting about 5–7 minutes; there were over 100 such overflows. Since September 29, the frequency of overflow activity has greatly decreased, although intermittent overflows continue at both north and south vents. Since yesterday September 30, north vent has had several overflows with minor dome fountaining. Eruptions from the north and south vents stopped during the early stages of dike emplaced yesterday afternoon, but the north vent resumed later during continued intrusive activity. The south vent had at least one overflow this morning after intrusive activity quieted down. In total, there were at least 10 overflows during and after the main intrusive event. Both north and south vents also spattered overnight and had persistent strong glow, and west vent had occasional glow. No other areas of incandescence were observed across the summit region last night.

Increased earthquake activity began yesterday, September 30, 2026, at approximately 2 p.m. HST, underneath Halemaʻumaʻu. In the past 24 hours, there were 98 shallow earthquakes located across the summit region, primarily underneath Halemaʻumaʻu, the largest of which was a magnitude (M) 3.4 earthquake at 9:52 p.m. H.S.T. Starting around 8 p.m. HST., summit tiltmeters began to show extremely rapid changes consistent with crack growth in an east-west orientation near the current vent area, suggesting that magma was intruding in this region. Most of the seismicity was confined to the western part of Halemaʻumaʻu and the northwestern part of Kaluapele, the summit caldera. Between 8 p.m. H.S.T. last night and 3 a.m. this morning, Uēkahuna tiltmeter (UWD) recorded approximately 38.5 microradians of inflation (this value has been corrected for a spike in the signal caused by the M3.4 earthquake). Since 3 a.m. H.S.T. this morning, summit inflation has flattened out and earthquake activity has decreased. A comparison of webcam imagery before and after the intrusion does not show any new ground cracking or eruption of lava in a new location.

During inter-episode pauses, the sulfur dioxide (SO₂) emission rate from the summit typically varies between 1,000 and 5,000 tonnes per day. Winds are currently forecast from the southeast.

Rift Zone Observations:

Rates of seismicity and ground deformation remain low in the East Rift Zone and Southwest Rift Zone. SO₂ emissions from the East Rift Zone remain below the detection limit. No significant ground deformation was recorded in either rift zone.

Analysis:

Monitoring data indicate that a shallow intrusion occurred overnight underneath Halemaʻumaʻu. Intrusive activity was strongest between 8 p.m. H.S.T. last night (September 30, 2026) and this morning around 3 a.m. H.S.T. Throughout the intrusion, eruptive activity similar to that observed since September 28 continued at north and south vents. At this stage, it appears that intrusive activity is complete, although conditions can change rapidly including eruption from a new vent with little or no seismicity or deformation.

The north vent resumed overflow activity on September 22. The south vent resumed overflow activity on September 27. The north and south vents continued to have intermittent overflows and spatter, strong glow and emitted flames overnight. Forecast windows for a potential episode 55 can no longer be modeled due to the irregular changes in inflation and deflation. The north vent has produced the last 11 high fountain events (episodes 44–54). It is not possible to say with certainty that this activity will lead to the onset of another fountain event at this time, although conditions remain favorable.

Because the summit system remains active and highly pressurized, the two most likely possibilities are that activity continues at the north-south-west vent complex, or it activates another existing weak crack system in the summit region. Neither of these events are likely to produce a strong seismic precursor, so the alert levels have been left at ORANGE/WATCH as the volcano continues to "exhibit heightened unrest with an increased potential for eruption". For further details about potential scenarios see the September 15 Status Report.

Kīlauea has been erupting episodically since December 23, 2024, from two vents (north and south) in Halema‘uma‘u. Lava fountaining episodes, which generally last for less than 12 hours, are separated by pauses of two or more 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

Summary of episode 54:

A detailed account of episode 54 is given in the HVO Status Report issued on August 25: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-08-26T05:56:38+00:00

• Episode 54 of the ongoing Halemaʻumaʻu eruption began around 10:30 a.m. HST and ended at 7:33 p.m. HST on August 25, 2026, after 9 hours of continuous lava fountaining. 
• The maximum lava fountain height from the north vent was approximately 500 feet (150 meters) above ground level, reached between 12:15 p.m. and 1:00 p.m. HST. Neither the south vent nor the new west vent (formerly the collapse pit) fountained during this episode.
• The maximum plume height was approximately 17,000 feet (5,200 meters) above sea level.
• Most tephra fall was restricted to the closed area of Hawaiʻi Volcanoes National Park, southwest of the active eruptive vents in Halemaʻumaʻu. However, HVO did also receive a report of trace Pele’s hair falling in the Ka‘ū district of the Island of Hawaiʻi.

Resources:

NOTE: HVO’s monitoring network is mostly recovered from recent power- and storm-related outages. Several summit stations will remain offline as we continue working to repair instruments and re-establish connections in our monitoring network.

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 lava fountains and eruptive activity can be found here: https://www.usgs.gov/observatories/hvo/observatory-messages
• Three Kīlauea summit livestream cameras 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:

Eruptive activity since December 2024 has been occurring within a closed area of Hawai'i Volcanoes National Park. However, last night's intrusion highlights that the location of eruptive activity could change. Intrusions can also be hazardous with potential to cause earthquakes, ground cracks, and small landslides. The primary hazards at Kilauea due to eruptive activity and/or intrusions are:

• 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/ and https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf 
• Lava flows: Hawaiian lava flows generally advance slowly downslope but destroy everything in their paths. Lava flows that erupt within Halemaʻumaʻu crater remain confined to Halemaʻumaʻu and Kaluapele. Lava flows from the eruption that started in December 2024 have been confined to Halemaʻumaʻu, an area closed to the public. Hazards associated with active or recent lava flows include hot and glassy (sharp) surfaces that can cause serious burns, abrasions, and lacerations upon contact with unprotected or exposed skin; uneven and rough terrain can lead to falls and other injuries; hot temperatures that can cause heat exhaustion or dehydration, or in heavy rain can produce steamy ground-fog that can be acidic, severely limiting visibility and sometimes causing difficulty breathing.
• Earthquakes and ground cracks: Shallow magma movement and eruptions can produce minor to severe ground fractures and subsidence features. These ground cracks can continue to widen and offset as magma migration continues, may have unstable overhanging edges, and should be avoided. Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes.

Additionally, close to the eruptive 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.