ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, October 17, 2026, 11:05 AM AKDT (Saturday, October 17, 2026, 19:05 UTC)
Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. A few small earthquakes were detected in the past day. No activity was observed in mostly cloudy webcam and satellite 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.
To view monitoring data and other information about Great Sitkin Volcano: https://avo.alaska.edu/volcano/great-sitkin
Unrest continues with elevated seismic activity with small earthquakes and tremor. Steam and sulfur dioxide gas emissions were visible in satellite and webcam views of the volcano over the past day.
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.
To view monitoring data and other information about Shishaldin Volcano: https://avo.alaska.edu/volcano/shishaldin
Kristi Wallace, Acting Scientist-in-Charge, USGS kwallace@usgs.gov (907) 786-7497
David Fee, Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 378-5460
Contact AVO: https://avo.alaska.edu/contact
The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
VAN is being reissued to drop the alert level from WATCH to ADVISORY and the color code from ORANGE to YELLOW. Episode 55 of the ongoing Halemaʻumaʻu eruption ended abruptly at 9:03 a.m. HST on October 17, 2026 after about 6 hours of continuous lava fountaining. Additional details on this eruptive episode will be provided in the next official report.
Hazard Analysis:
Volcanic Gas: water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) 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 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 at the links below:
Lava flows: lava 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 exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. 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. 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.
HVO continues to closely monitor Kīlauea and will issue additional notices as needed based on activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates
More Information:
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes
WMPA01 PHVO 171959 VONA DTG: 20261017/1959Z VOLCANO: KILAUEA 332010 PSN: N1925 W15517 AREA: HAWAII SOURCE ELEV: 4091FT AMSL NOTICE NR: 2026/69 CURRENT COLOUR CODE: YELLOW PREVIOUS COLOUR CODE: ORANGE SVO: HAWAIIAN VOLCANO OBSERVATORY ACT STS: ERUPTION OCCURRED ONSET: UNKNOWN DUR: UNKNOWN VA CLD HGT: UNKNOWN HGT SOURCE: NO VA CLD PRODUCED MOV: UNKNOWN CTC: HVO DUTY SCIENTIST: 808-785-3144 RMK: VONA IS BEING REISSUED TO DROP THE COLOR CODE FROM ORANGE TO YELLOW. LAVA FOUNTAIN EPISODE 55 ENDED AT KILAUEA SUMMIT AT 9:03 A.M. HST. FOUNTAIN ACTIVITY IN THIS AREA UNLIKELY FOR THE NEXT SEVERAL WEEKS. REFER TO NWS FOR INFORMATION ON DRIFTING PLUME. NXT NOTICE: A NEW VONA WILL BE ISSUED IF COND CHANGE SIGNIFICANTLY OR IF THE COLOR CODE CHANGES NNNN
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Saturday, October 17, 2026, 9:50 AM HST (Saturday, October 17, 2026, 19:50 UTC)
Summit Observations:
Lava fountain episode 55 in Halemaʻumaʻu at the summit of Kīlauea began at 3:19 a.m. HST October 17, 2026, and ended at 9:03 a.m. HST on October 17, 2026, after about 6 hours of continuous fountaining from the north vent.
The onset of episode 55 fountain began at 3:19 a.m. HST as fountains from the north vent began to rapidly increase in height. Maximum fountain heights of 720 feet (220 m) were recorded between 4:50 and 5:10 a.m. HST with the plume cloud reaching up to 25,000 feet (7500 m) above sea level (a.s.l.) during that time. The fountain dropped quickly back to 650 feet and then to 500 feet by 7:00 a.m. HST this morning and was down to about 300 feet (100 m) high by 8:00 a.m. HST. Likewise, the plume cloud dropped to under 13,000 feet (4000 m) a.s.l. by 7:30 a.m. HST. Waning behavior was noted at around 8:50 a.m. and by 9:03 a.m. fountaining had ended. This was accompanied by a return of inflationary tilt patterns and a decrease in summit RSAM. The instantaneous effusion rate peaked at about 1000 cubic yards (770 cubic meters) per second at approximately 5:00 a.m. HST, with an average effusion rate of 380 cubic yards (290 cubic meters) per second for the entire fountaining episode. Preliminary estimates indicate about 9 million cubic yards (7 million cubic meters) of lava erupted during this episode. The repose period leading up to episode 55 was the longest and most complex since the eruption began on December 23, 2024. Initial precursory flows erupted on September 7 preceding episode 55 fountains by 39 days. The next longest period of precursory activity was 6 days. The repose period prior to episode 55 included a series of new vents opening up on September 14-16 along the base of the cliffs on the west side of Halemʻamaʻu as well as an intrusion beneath the northwestern part of Kaluapele September 30 to October 1.
Lava flows flooded the western part of Halema'uma'u crater and by 8:30 a.m. HST were covering 75% of the crater floor. Fountaining was preceded by continuous overflows from the south vent that began at 5:56 a.m. HST on October 16 and continued until the start of fountaining from the north vent early this morning. Intermittent overflows began from the north vent at 6:11 p.m. HST on October 16 and after 6 small flows started to erupt continuously at 11:35 p.m. last night. Rare overflows from the west vent began at 10:49 p.m. HST last night, with three small overflows preceding the onset of continuous eruption of lava at 2:23 a.m. HST. The north vent fountains doubled in size right around 3:19 a.m. HST at the onset of episode 55, while the south and west vents had small dome fountains that continued to feed flows. The south vent overflows ended at 3:55 a.m. HST while the west vent fountains and overflows were drowned by the north vent at 4:13 a.m. HST.
Tremor had been continuous and steady throughout most of yesterday but began to increase around 2:45 a.m. HST this morning. By 3:19 a.m. HST background tremor measured by RSAM indicate that the intensity of tremor had doubled at the same time rapid deflationary tilt started at the summit. This along with the doubling of the north vent fountain height defined the onset of episode 55 fountaining even though the fountain was less than 100 feet (30 m) high at the time. Tremor rapidly increased to about 10 times background by 4:30 a.m. HST about 20 minutes prior to the fountain reaching its maximum height of 720 feet. Tremor slowly dropped since that time, until the end of fountaining at 9:03 a.m., when it decreased to lower values typical of the immediate post-fountaining period. There were 22 small earthquakes beneath the summit region in the last 24 hours, but only 3 of those occurred in the last 8 hours.
The Uēkahuna (UWD) tiltmeter recorded gradual inflationary tilt throughout the day yesterday until it plateaued around midnight. The tiltmeter recorded minor deflationary tilt beginning around 1:30 a.m. HST. Rapid deflationary tilt began at 3:19 a.m. when the summit magma chamber began to rapidly deflate at the onset of episode 55 fountaining. This quickly turned to inflationary tilt once again with the end of fountaining at 9:03 a.m., as is typically observed following fountaining episodes.
During fountain episodes, the sulfur dioxide (SO2) emission rate from the summit typically 100,000 tonnes per day. Plumes of volcanic gas and tephra reached as high as 25,000 feet (7000 m) above sea level but dropped rapidly to under 20,000 feet above sea level. Winds below 20,000 feet were out of the northeast, pushing the plume to the southwest. Most tephra fall is expected to occur southwest of the vent area within the closed area of Hawaiʻī Volcanoes National Park, but traces of fine ash and Peleʻs hair in Pāhala and possibly other communities to the southwest in Kaʻū. Sulfur dioxide (SO2) emission rates from the summit are expected to drop back to 1,000-5,000 tonnes per day.
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 previous 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 became 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 tiltmeters have recorded inflationary tilt interspersed with periods of deflationary or flat tilt. The vigorous overflows from the south vent starting yesterday morning and joined by the north and west vents late last night appear to have purged the system of older degassed magma and allowed more water-rich magma into the conduit to trigger episode 55 fountaining from the north vent.
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.
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:
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.
More Information:
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi and American Samoa.
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes
Episode 55 of the ongoing Halemaʻumaʻu eruption ended abruptly at 9:03 a.m. HST on October 17, 2026 after about 6 hours of continuous lava fountaining. Additional details on this eruptive episode will be provided in the next official report.
Hazard Analysis:
Volcanic Gas: water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) 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 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 at the links below:
Lava flows: lava 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 exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. 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. 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.
HVO continues to closely monitor Kīlauea and will issue additional notices as needed based on activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates
More Information:
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes
WMPA01 PHVO 171911 VONA DTG: 20261017/1911Z VOLCANO: KILAUEA 332010 PSN: N1925 W15517 AREA: HAWAII SOURCE ELEV: 4091FT AMSL NOTICE NR: 2026/68 CURRENT COLOUR CODE: ORANGE PREVIOUS COLOUR CODE: ORANGE SVO: HAWAIIAN VOLCANO OBSERVATORY ACT STS: ERUPTION OCCURRED ONSET: UNKNOWN DUR: UNKNOWN VA CLD HGT: UNKNOWN HGT SOURCE: NO VA CLD PRODUCED MOV: UNKNOWN CTC: HVO DUTY SCIENTIST: 808-785-3144 RMK: LAVA FOUNTAIN EPISODE 55 ENDED AT KILAUEA SUMMIT AT 9:03 A.M. HST. FOUNTAIN ACTIVITY IN THIS AREA UNLIKELY FOR THE NEXT SEVERAL WEEKS. REFER TO NWS FOR INFORMATION ON DRIFTING PLUME. NXT NOTICE: A NEW VONA WILL BE ISSUED IF COND CHANGE SIGNIFICANTLY OR IF THE COLOR CODE CHANGES NNNN
Episode 55 of lava fountaining in Halemaʻumaʻu began at the summit of Kīlauea began at 3:19 a.m. HST on October 17, 2026 and continues as of this notice. The fountain from the north vent reached a maximum height of just over 700 feet (220 m) by 5:00 a.m. HST.
The plume from this eruption is reaching about 25,000 feet above sea level. Winds are blowing from the north-northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the south-southwest direction from Halemaʻumaʻu. Current radar images show significant tephra within the plume up to only 8,000 above sea level. The National Weather Service reports winds above 20,000 feet coming from the west.
Most lava fountaining episodes since December 23, 2024, have continued for a day or less.
Hazard Analysis:
Volcanic Gas: water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) are continuously released during an eruption. SO2 reacts in the atmosphere to create the visible haze known as vog (volcanic air pollution) downwind, which may cause respiratory and other problems. 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/
Lava flows: generally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera.
Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. 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. 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.
HVO continues to closely monitor Kīlauea and will issue additional notices as needed based on activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates
More Information:
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes
WMPA01 PHVO 171522 VONA DTG: 20261017/1522Z VOLCANO: KILAUEA 332010 PSN: N1925 W15517 AREA: HAWAII SOURCE ELEV: 4091FT AMSL NOTICE NR: 2026/67 CURRENT COLOUR CODE: ORANGE PREVIOUS COLOUR CODE: ORANGE SVO: HAWAIIAN VOLCANO OBSERVATORY ACT STS: ERUPTION ONGOING ONSET: 20261017/1430Z DUR: ONGOING EPISODIC VA CLD HGT: 25000FT AMSL HGT SOURCE: WEBCAM MOV: SW CTC: HVO DUTY SCIENTIST: 808-785-3144 RMK: LAVA FOUNTAIN EPISODE 55 CONTINUES AT KILAUEA SUMMIT. FOUNTAINS CURRENTLY REACHING 700 FT AGL. WEBCAMS SHOW THE PLUME AT ABOUT 25000 FT AMSL. FALLOUT LIKELY IN THE SOUTHWEST DIRECTION DOWNWIND OF VENTS. ABOVE 20000 FT AMSL THE PLUME MAY MOVE TO THE EAST. NXT NOTICE: A NEW VONA WILL BE ISSUED IF COND CHANGE SIGNIFICANTLY OR IF THE COLOR CODE CHANGES NNNN
Episode 55 of lava fountaining in Halemaʻumaʻu began at the summit of Kīlauea began at 3:19 AM HST on October 17, 2026.
Fountain heights are relatively low at about 100-150 feet (30-45 m), and it is not clear whether this episode will evolve to the same heights as previous episodes. Continuous overflows from the vents began yesterday, October 16, just before 6 a.m. HST and transitioned into episode 55 fountains at 3:19 a.m. HST this morning. The current forecast is for winds are blowing from the north-northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the south-southwest direction from Halemaʻumaʻu.
Most lava fountaining episodes since December 23, 2024, have continued for a day or less.
Hazard Analysis:
Volcanic Gas: water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) are continuously released during an eruption. SO2 reacts in the atmosphere to create the visible haze known as vog (volcanic air pollution) downwind, which may cause respiratory and other problems. 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/
Lava flows: ggenerally advance slowly downslope, and during this eruption flows have been confined to Halemaʻumaʻu crater and the southwest side of Kaluapele, Kīlauea's summit caldera.
Other significant hazards exist around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes. 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. 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.
HVO continues to closely monitor Kīlauea and will issue additional notices as needed based on activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates
More Information:
Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes
WMPA01 PHVO 171343 VONA DTG: 20261017/1343Z VOLCANO: KILAUEA 332010 PSN: N1925 W15517 AREA: HAWAII SOURCE ELEV: 4091FT AMSL NOTICE NR: 2026/66 CURRENT COLOUR CODE: ORANGE PREVIOUS COLOUR CODE: ORANGE SVO: HAWAIIAN VOLCANO OBSERVATORY ACT STS: ERUPTION ONGOING ONSET: UNKNOWN DUR: UNKNOWN VA CLD HGT: UNKNOWN HGT SOURCE: WEBCAM MOV: UNKNOWN CTC: HVO DUTY SCIENTIST: 808-785-3144 RMK: LAVA FOUNTAIN EPISODE 55 STARTED AT KILAUEA SUMMIT. CURRENT FOUNTAIN HEIGHTS 100 FT AGL. NXT NOTICE: A NEW VONA WILL BE ISSUED IF COND CHANGE SIGNIFICANTLY OR IF THE COLOR CODE CHANGES NNNN