USGS Volcano Notice - DOI-USGS-HVO-2026-10-16T18:37:16+00:00

Summit Observations:

Multiple overflows from the south vent were observed through the night starting at 10:16 PM HST. There were 15 overflows that lasted less than 5 minutes and were small, advancing less than 100 feet (30 m) from the vent. Then at 5:10 a.m. HST, a high-volume overflow coated the entire area within 300 feet (100 m) of the vent with pahoehoe in 10 minutes. This was followed by the current south vent overflows which began and 5:56 a.m. HST and continue at this time. A small dome fountain within the vent has been feeding multiple channels of pahoehoe that cover the near vent area and extend near a half a mile (about a kilometer) from the vent. The volume of lava and the size of the dome fountain appear to wax and wane over time, but continues to feed vigorous overflow channels. Spatter from all three vents (north, south, and west) was also observed overnight, as well consistent glow and occasional flames. 

Irregular tremor bursts gave way to more continuous tremor around 6 a.m. HST, about the same time the south vent became continuously active and drainback events stopped. Twenty-one earthquakes were recorded over the past day, mostly in the southern and eastern regions of the summit region of Kīlauea.

Summit tiltmeters have shown minor changes in tilt, with an overall slight inflationary trend since Wednesday. GPS stations on opposite sides of Halemaʻumaʻu (CRIM and UWEV) show a small increase in length since the end of September suggesting longer-term inflation of the summit magma reservoir.

During inter-episode pauses, the sulfur dioxide (SO₂) emission rate from the summit typically varies between 1,000 and 5,000 tonnes per day. Plumes of volcanic gas are visible from the vents in day-time webcam views. Winds are currently forecast from the north-northeast through today.

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:

Kīlauea had been erupting episodically between December 23, 2024, and August 25, 2026, from two vents (north and south) in Halema‘uma‘u at the summit. Lava fountaining episodes generally lasted for less than 12 hours and were separated by pauses of two or more weeks. Irregular patterns of ground deformation at Kīlauea summit since the most recent lava fountaining episode, number 54 on August 25, 2026, prevent forecast modeling for when the next fountaining episode can occur. Ground deformation patterns indicate the magma chamber beneath Halemaʻumaʻu is pressurized beyond the level typically seen before recent fountaining events. This pattern was disrupted by the dike intrusion on September 30-October 1 and since then summit tilt has increased slowly with interspersed periods of decreased or flat tilt. The vigorous overflows from the south vent this morning indicate that magma remains very near the surface in the established vent complex and continues to be able to generate smaller dome fountains. It is possible that another fountaining episode from the north-south vent complex could occur; however, intrusive activity underneath Kaluapele is also possible, or magma could exploit existing weak crack systems in the summit region to erupt passively (with little or no seismicity or deformation). 

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. Kīlauea volcano alert level and aviation color code remain at WATCH/ORANGE and conditions could change rapidly. For further details, see the recent official notices listed below. 

• October 7 Status Report summarizing recent intrusive activity and implications: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-10-08T01:00:28+00:00 
• October 7 Hawaiʻi Volcanoes National Park News Release announcing closures related to recent activity: https://www.nps.gov/havo/learn/news/20261007-nr-trail-closures.htm 
• October 1 Volcano Watch summarizing recent intrusive activity: https://www.usgs.gov/observatories/hvo/news/volcano-watch-intrusion-during-eruption-summit-kilauea 
• October 1 Status Report published during recent intrusive activity: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2026-10-01T08:14:21+00:00
• September 15 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

Hazards:

Eruptive activity since December 2024 has been occurring within a closed area of Hawai'i Volcanoes National Park. However, recent intrusions highlight 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 Kīlauea 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 remain confined to the crater, including those during the eruption that started in December 2024. However, intrusive activity could result in lava flows outside of Halemaʻumaʻu. 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.