USGS Volcanoes: Notices released in the last day.

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Minor earthquakes were detected in the past day. Elevated surface temperatures were observed in satellite data. No activity was observed in cloudy webcam images over the past day.

The current eruption began in July 2021. Since then, lava flows have 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, webcams, and regional infrasound and lightning networks.

Unrest continues with elevated seismic and infrasound activity. Sulfur dioxide emissions were observed in satellite data over the past day. No activity was observed in cloudy satellite and webcam images.

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 lightning data, and satellite images to detect eruptions. 

See these notices issued yesterday, October 7: 

• October 7 Hawaiian Volcano Observatory 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 

Summit Observations:

Both the north and south vents in Halemaʻumaʻu showed strong glow and flames in overnight webcam imagery, with minor amounts of spatter erupted by the north vent. Robust plumes of volcanic gas emanate from both vents in day-time webcam views. 

In the past 24 hours, there were 6 shallow earthquakes located across the summit region of Kīlauea. The Uēkahuna tiltmeter (UWD) recorded approximately 1 microradian of inflation between 8 a.m. and 4 p.m. yesterday, October 7. Since then, UWD has shown slow deflation totaling about a microradian, resulting in no net change in tilt over the past day.

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 south/southwest, which could result in voggy conditions in the communities around Kīlauea summit.

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 in inflation and deflation 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. 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 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.

Summary

Recent satellite imagery shows the intrusion of magma that was emplaced on September 30 to October 1, 2026, followed fracture systems created in Kaluapele (Kīlauea’s summit caldera) during the 2018 collapse of Halemaʻumaʻu. This intrusion was emplaced very near the surface north of Halemaʻumaʻu resulting in a narrow band of surface deformation and new, small surface fractures.

Photos and map related to the intrusive activity— Kīlauea summit intrusion cracks and ground deformation | U.S. Geological Survey

Emplacement of the Dike Intrusion

An earthquake swarm began around 2 p.m. HST on the afternoon of September 30^th about 1 mile (1.5 km) beneath the vent complex in Halemaʻumaʻu. About 30 located events occurred in this area and by about 8 p.m. HST, the seismicity had moved northeastward at the same depth, extending from the rim of Halemaʻumaʻu well into Kaluapele. An additional 50 events were located in this area before 4 a.m. HST on October 1. Earthquakes continued to occur at diminishing rates over the next day, with the largest event being a magnitude-3.5 at 7:55 a.m. HST on October 2, located beneath the northern edge of Halemaʻumaʻu. About 130 earthquakes were recorded in total. 

The USGS Hawaiian Volcano Observatory issued a Status Report describing the intrusion of a dike, a sheet-like vertical body of magma, into the northwestern part of Kaluapele. Dikes are formed when magma intrudes sub-vertical cracks as it moves beneath the surface. The earthquakes were accompanied by a rapid increase in the rate of tilt at the Uēkahuna tiltmeter, which showed more than 40 microradians of change towards the northwest over about eighteen hours. The other summit tiltmeters saw changes of only a few microradians as reported in the Daily Update for Kīlauea on October 1. The localized nature of the tilt changes indicated they were caused by the intrusion of magma near the western rim of Kaluapele and much closer to the surface than the Halemaʻumaʻu magma chamber. The event was described in detail in the Volcano Watch published later in the day on October 1. The combination of seismicity and tiltmeter data was able to provide the timing of events and the general location, but not the shape and size of the dike.

Location and Shape of the Dike Intrusion

Recent Interferometric Synthetic Apeture Radar (InSAR) satellite images were used to construct an interferogram that more precisely determines the shape and location of the dike intrusion. The interferogram requires a satellite image acquired before and one after the event, so it can be several days to two weeks before the pair of images are both acquired. Orbital passes by the Italian Space Agency’s COSMO-SkyMed Second Generation satellites on September 24 and October 2 were used to construct an interferogram map showing the interpreted location and length of dike intrusion.

The patterns of surface deformation show that the dike extends from the established vent area in Halemaʻumaʻu and cuts across the northwestern part of Kaluapele. The deforming areas following parallel to the western rim of Halemaʻumaʻu and Kaluapele are very narrow and elongate, mapping the path of magma intruding within a thousand feet (about 300 meters) or less of the surface.  The path of the dike follows fractures in the caldera floor that formed in 2018 and created a series of new, small fractures that were identified on other satellite images.

Interpretation

The rising elevation of the established north-south-west vents over the course of this eruption has increased the pressure necessary to push magma out of the vents and trigger a major fountain episode.  The normal pattern of consistent rates of summit inflation prior to the onset of fountain episodes began to change to stepwise inflation prior to episode 51. Episodes 51-54 all showed similar patterns of inflation, broken by periods of no inflation that could last for several days. Since the end of fountaining episode 54 on August 25, these inconsistent inflationary patterns have continued.  The opening of six vents on and below the northwest wall of Halemaʻumaʻu on September 14-16 suggests that magma is able to intrude into pre-existing weak, fractured areas along the northern and western boundaries of Halemaʻumaʻu without having to create new space (that event lacked earthquakes and significant deformation). The September 30-October 1 intrusion shows that magma is also exploiting fractures formed within Kaluapele during the 2018 collapse, and that event was accompanied by earthquakes and ground deformation as cracks either open or expand and compress adjacent rocks. The occurrence of these two small-volume intrusions below Kilauea’s summit region within the past month suggests the pressure required to erupt dense degassed magma from the established vents is also high enough to allow magma to exploit weaknesses below the surface along the pre-existing, 2018 crack systems. Magma is being injected into these weak areas as dikes that start from the subsurface dike below the established vents and move northwards into the fractured areas.

Possible Outcomes

The impact of Kīlauea summit increased pressurization and earthquakes on the next episode of lava fountaining, if any, is unknown at this time. It is not possible to forecast an exact outcome of this activity. It is clear that the patterns of forecastable eruptive behavior at Kīlauea summit are no longer being observed in volcano monitoring data. Some potential scenarios are described below based on summit conditions and past episodic eruptions of Kīlauea (1983 Puʻuʻōʻō and the 1969 Maunaulu eruptions). These past eruptions both continued after lava fountaining episodes ended, with fissures opening nearby or collapse of the vents leading to continuous eruption of lava flows.  The possible scenarios presented in the Status Update of September 15 have been updated and presented below. While the current activity is no longer necessarily precursory to a fountaining episode, it is evidence of growing instability in the system that may result in significant change. For both the Puʻuʻōʻō and Maunaulu eruptions the change was from short-lived, high volume episodic fountaining to long-lived, low volume continuous eruption of lava.

• Eruption returns to fountaining: It remains possible that a fountaining episode from the established north-south-west vent complex in Halemaʻumaʻu could still occur. The conditions necessary for the onset of a fountaining episode, including vertical cylindrical conduits, high magma pressure, and continued input of magma into the shallow Halemaʻumaʻu magma, still exist.  However, intermittent overflows since September 6 have likely allowed the magma in the conduits to degas more magma, perhaps inhibiting the rise of the hotter, more gas-rich magma necessary to trigger a fountaining episode. A period of prolonged and larger-volume overflows may be required to allow more gas-rich magma to rise up into the conduits.
• Continued intrusions within the summit region: Magma could continue to exploit weak regions along the margins of Halemaʻumaʻu and beneath Kaluapele aseismically (without earthquakes) or accompanied by earthquakes and changes in ground deformation patterns.  Continued intrusive activity in the same region as the September 30-October 1 dike intrusion is the most likely, as there are multiple crack systems in the area north of Halemaʻumaʻu crater.  It is also possible that increased pressure could open other fracture systems along the south and west margins of Halemaʻumaʻu but this area was not heavily fractured during the 2018 summit collapse.
• Formation of new vent(s) in summit region: Magma could establish a new shallow pathway toward the surface, potentially resulting in new vents erupting lava within the summit caldera.  There are two likely scenarios, one would produce earthquakes, potentially with tightly clustered locations, along with changes in the patterns of ground deformation indicative of shallow crack formation, similar to what occurred during the new vent formation during episode 30 on August 6, 2025, when a crack in the southwest wall of Halemaʻumaʻu briefly erupted.  The other is passive eruption from vents such as happened on and below the northwest wall of Halemaʻumaʻu on September 14-16.  Lava erupted along existing crack features without significant seismicity or changes in ground deformation. Currently the most likely place for new vents to erupt would be along the base of the northern wall of Halemaʻumaʻu crater.  This area is at a lower elevation than the current vent complex and was the site of the two shallow magnitude 3.4-3.5 earthquakes associated with the dike intrusion. Eruptions on the floor of Kaluapele are less likely as they would be at a higher elevation than the established vent complex.
• Intrusion into the upper parts of the Southwest Rift Zone or East Rift Zone: Magma could migrate into the upper portion of the Southwest Rift Zone or the East Rift Zone in Hawaiʻi Volcanoes National Park. In this scenario, we would expect an extended period of increased rates of earthquakes migrating from the summit towards a rift zone, along with ground deformation indicative of summit magma chamber deflation. 
• The eruption could stop:  Changes in magma supply and stress within the volcano could result in the end of this eruption.

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.

Hazards

Eruptions within Halemaʻumaʻu or Kaluapele have the potential to produce fountains and lava flows along with associated tephra and volcanic gases. Most of these impacts will be confined to closed areas within and surrounding Kaluapele.  Under certain wind conditions, viewing areas surrounding Kaluapele can be exposed to volcanic gas and tephra fall.

Periods of elevated seismicity may occur at anytime and have the potential to create dangerous rockfalls near and beneath the cliffs surrounding Kaluapele. The highest hazard exposures are along the unstable cliff edges and beneath cliffs. Earthquakes are unpredictable and can occur rapidly; avoid cliff edges and the base of cliffs for safety.

Hawaiʻi Volcanoes National Park establishes closed areas for visitor safety.

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