ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Wednesday, December 24, 2025, 10:14 AM AKST (Wednesday, December 24, 2025, 19:14 UTC)
Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Nothing unusual was observed in cloudy satellite and webcam views. Seismicity was mostly quiet over the past day.
The current lava eruption began in July 2021 and since then has 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 and web cameras, and regional infrasound and lightning networks.
To view monitoring data and other information about Great Sitkin: https://avo.alaska.edu/volcano/great-sitkin
Shishaldin Volcano continues to experience unrest with occasional small earthquakes detected throughout the day yesterday. Nothing unusual was observed cloudy satellite views. Weak steaming from the summit was observed in occasionally clear webcam views.
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 lighting data, and satellite images to detect eruptions.
To view monitoring data and other information about Shishaldin: https://avo.alaska.edu/volcano/shishaldin
Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497
Jessica Larsen, Acting Coordinating Scientist, UAF jflarsen@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.
ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Tuesday, December 23, 2025, 11:49 AM AKST (Tuesday, December 23, 2025, 20:49 UTC)
Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Nothing unusual was observed in partly cloudy satellite and webcam views. Seismicity was mostly quiet over the past day.
The current lava eruption began in July 2021 and since then has 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 and web cameras, and regional infrasound and lightning networks.
To view monitoring data and other information about Great Sitkin: https://avo.alaska.edu/volcano/great-sitkin
Shishaldin Volcano continues to experience unrest with occasional small earthquakes detected throughout the day yesterday. Nothing unusual was observed in mostly clear satellite and webcam views. Lenticular clouds over the summit prevented any view of potential weak steaming.
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 lighting data, and satellite images to detect eruptions.
To view monitoring data and other information about Shishaldin: https://avo.alaska.edu/volcano/shishaldin
Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497
Jessica Larsen, Acting Coordinating Scientist, UAF jflarsen@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.
The Alaska Volcano Observatory (AVO) is no longer receiving data from seismic stations on Aniakchak Volcano due to an ongoing power outage at the receive facility in Port Heiden. As a result AVO unable to (1) assess whether the volcano may be building towards an eruption and (2) quickly confirm or dismiss reports of activity.
Because this volcano is no longer seismically monitored at adequate levels, the Aviation Color Code and Volcano Alert Level are changed to UNASSIGNED/UNASSIGNED. As at other volcanoes without real-time seismic networks, AVO will continue to use satellite data, regional seismic, infrasound and lightning networks, and reports from pilots and ground observers to detect signs of eruptive activity.
Aniakchak volcano, located in the central portion of the Alaska Peninsula, consists of a stratovolcano edifice with a 6 mile (10 km) diameter summit caldera. The caldera-forming eruption occurred around 3,500 years ago. Post-caldera eruptions have produced lava domes, tuff cones, and larger spatter and scoria cone structures, including Half-Cone and Vent Mountain, all within the caldera. The most recent eruption occurred in 1931 and created a new vent and lava flows on the western caldera floor while spreading ash over much of southwestern Alaska. Aniakchak volcano is 16 miles (26 km) southeast of the nearest community, Port Heiden, and 416 miles (670 km) southwest of Anchorage, Alaska. It is located in Aniakchak National Monument and Preserve.
Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497
Jessica Larsen, Acting Coordinating Scientist, UAF jflarsen@alaska.edu (907) 378-5460
A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu.
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.
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20251223/2023Z) |
| (3) Volcano: | Aniakchak (VNUM #312090) |
| (4) Current Color Code: | UNASSIGNED |
| (5) Previous Color Code: | GREEN |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | 2025/A775 |
| (8) Volcano Location: | N 56 deg 54 min W 158 deg 12 min |
| (9) Area: | Alaska Peninsula |
| (10) Summit Elevation: | 4400 ft (1341 m) |
| (11) Volcanic Activity Summary: |
The Alaska Volcano Observatory (AVO) is no longer receiving data from seismic stations on Aniakchak Volcano due to an ongoing power outage at the receive facility in Port Heiden. As a result AVO unable to (1) assess whether the volcano may be building towards an eruption and (2) quickly confirm or dismiss reports of activity. Because this volcano is no longer seismically monitored at adequate levels, the Aviation Color Code and Volcano Alert Level are changed to UNASSIGNED/UNASSIGNED. As at other volcanoes without real-time seismic networks, AVO will continue to use satellite data, regional seismic, infrasound and lightning networks, and reports from pilots and ground observers to detect signs of eruptive activity. |
| (12) Volcanic cloud height: | none |
| (13) Other volcanic cloud information: | none |
| (14) Remarks: | Aniakchak volcano, located in the central portion of the Alaska Peninsula, consists of a stratovolcano edifice with a 6 mile (10 km) diameter summit caldera. The caldera-forming eruption occurred around 3,500 years ago. Post-caldera eruptions have produced lava domes, tuff cones, and larger spatter and scoria cone structures, including Half-Cone and Vent Mountain, all within the caldera. The most recent eruption occurred in 1931 and created a new vent and lava flows on the western caldera floor while spreading ash over much of southwestern Alaska. Aniakchak volcano is 16 miles (26 km) southeast of the nearest community, Port Heiden, and 416 miles (670 km) southwest of Anchorage, Alaska. It is located in Aniakchak National Monument and Preserve. |
| (15) Contacts: | Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497 Jessica Larsen, Acting Coordinating Scientist, UAF jflarsen@alaska.edu (907) 378-5460 |
| (16) Next Notice: | A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu. |
HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Wednesday, December 24, 2025, 9:25 AM HST (Wednesday, December 24, 2025, 19:25 UTC)
Activity Summary:
Episode 39 fountaining began yesterday at 8:20 p.m. HST, December 23, almost 1 year to the day on the anniversary of the ongoing episodic eruption that began at 2:20 a.m. HST on December 23, 2024. Fountains continued for just under 6 hours ending at 2:13 a.m. this morning (December 24) and reached a maximum height of about 1400 feet (425 meters). The onset of the next fountain episode is about 2 weeks away. No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.
Summit Observations:
Kīlauea is no longer erupting (see the section "Recap of the last episode" for details about the episode 39 eruption). Just before dawn this morning incandescence was present across Halemaʻumaʻu crater. Flows on the eastern crater floor continued to move fed by lava draining from higher elevations around the vents. Incandescent spots and movement of flows are expected to continue for the next several days, especially in the area around the vents.
Since the end of episode 39, Kīlauea has inflated 1.75 microradians as recorded on the UWD tiltmeter this morning.
Volcanic gas emission rates have dropped significantly since the end of episode 39 but probably remain in the range of 1,000 to 5,000 tonnes of SO2 per day typically observed during previous eruptive pauses.
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 and presence of low level volcanic tremor indicate another fountain episode is likely to occur. There is insufficient data for modeling, but the next episode is likely about 2 weeks away.
Kīlauea has been erupting episodically since December 23, 2024, primarily from two vents (north and south) in Halema‘uma‘u. Eruptive episodes, which can last up to 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 39 fountaining from the south vent stopped at approximately 2:13 a.m. HST on December 24 after 5.9 hours of sustained fountaining. The two vents within the north cone both stopped slightly earlier at 2:00 a.m. HST. Sustained fountaining began at 8:20 p.m. HST from the north and south vents after just under 2 hours of precursory overflows. Fountains rapidly grew to several hundred feet high and by 9:30 p.m. HST had reach maximum estimated heights of 1400 feet (425 meters) for the south fountain and 900 feet for the north fountain. The main fountain from the north cone came from the "right hand" vent (as viewed from V1cam, which is pointed south), but a much smaller fountain, 100-200 feet (30-60 meters) high, began at about 8:45 p.m. HST and lasted until the north vent stopped fountaining. This "triple" fountain lasted through most of the eruption with the south fountains highest followed by the "right hand" north vent (about 2/3 the height of the south fountains) and the much smaller "left hand" north vent fountains (about 10-20% of the south vent fountain height). The highest peak or instantaneous effusion rate of 960 cubic yards per second (800 cubic meters per second) occurred about 9 p.m. HST just before the south and north vents reached their maximum heights. Episode 39 ended with an average effusion rate of 250 cubic yards per second (190 cubic meters per second). An estimated 12 million cubic yards (9.3 million cubic meters) of lava erupted and covered about 50-60% of the floor of Halemaʻumaʻu crater. The Uēkahuna tiltmeter (UWD) recorded about 26.8 microradians of deflationary tilt during episode 39.
The following links provide more information about the current eruption that began on December 23, 2024:
Hazards:
This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one major hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
Another major hazard is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity that can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments (tephra) including volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1–3 miles (1–5 kilometers) of the eruptive vent(s), with the highest concentrations immediately downwind of the vent(s). Various volcanic fragments have fallen on Highway 11 west of Hawai'i Volcanoes National Park at times, depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation and can also contaminate catchment water supplies. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf
Hawaiian 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 also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. 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 39 of the ongoing Halemaʻumaʻu eruption ended abruptly at 2:13 a.m. HST on December 24, 2025 after 5.9 hours of continuous fountaining (the start time was revised from 8:10 p.m. to 8:20 p.m. HST on December 23 based on tilt and tremor data).
The north vent stopped erupting at approximately 2:00 a.m. HST. The south vent stopped erupting at approximately 2:13 a.m. HST, marking the end of the episode. Lava fountains from the south vent reached up to 1400 ft (420 m) while north vent fountains were just under 1000 feet (280 meters) around 9:30 p.m. HST on December 23. Episode 39 fountains lasted for 5.9 hours and produced an estimated 13 million cubic yards (10 million cubic meters) of lava. The combined average eruption rate was over 250 cubic yards per second (190 cubic meters per second) from the dual fountains. Lava flows from the fountains covered about 60-70% of the floor of Halemaʻumaʻu crater.
Volcanic gas emissions have greatly decreased. Lava flows from this episode on the floor of Halemaʻumaʻu within the southern part of Kaluapele (Kīlauea caldera) may continue to exhibit slow movement or incandescence as they cool and solidify over the coming days.
The Uēkahuna tiltmeter (UWD) recorded about 26.3 microradians of deflationary tilt during this episode. The end of the eruption was coincident with a rapid change from deflation to inflation at the summit and a decrease in seismic tremor intensity.
Most episodes of Halemaʻumaʻu lava fountaining since the eruption started on December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days.
No changes have been detected in the East Rift Zone or Southwest Rift Zone.
Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park.
Hazard Analysis:
This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Pumice and other volcanic fragments have fallen on Highway 11 west of Hawaiʻi Volcanoes National Park depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf
Hawaiian 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 also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. 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 a VAN/VONA at the start of the next eruptive episode. If possible, HVO will also issue a Status Report beforehand at the onset of low-level precursory 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
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20251224/1233Z) |
| (3) Volcano: | Kilauea (VNUM #332010) |
| (4) Current Color Code: | ORANGE |
| (5) Previous Color Code: | ORANGE |
| (6) Source: | Hawaiian Volcano Observatory |
| (7) Notice Number: | 2025/H556 |
| (8) Volcano Location: | N 19 deg 25 min W 155 deg 17 min |
| (9) Area: | Hawaii |
| (10) Summit Elevation: | 4091 ft (1247 m) |
| (11) Volcanic Activity Summary: |
Episode 39 of the ongoing Halemaʻumaʻu eruption ended abruptly at 2:13 a.m. HST on December 24, 2025 after 5.9 hours of continuous fountaining (the start time was revised from 8:10 p.m. to 8:20 p.m. HST on December 23 based on tilt and tremor data). The north vent stopped erupting at approximately 2:00 a.m. HST. The south vent stopped erupting at approximately 2:13 a.m. HST, marking the end of the episode. Lava fountains from the south vent reached up to 1400 ft (420 m) while north vent fountains were just under 1000 feet (280 meters) around 9:30 p.m. HST on December 23. Episode 39 fountains lasted for 5.9 hours and produced an estimated 13 million cubic yards (10 million cubic meters) of lava. The combined average eruption rate was over 250 cubic yards per second (190 cubic meters per second) from the dual fountains. Lava flows from the fountains covered about 60-70% of the floor of Halemaʻumaʻu crater. Volcanic gas emissions have greatly decreased. Lava flows from this episode on the floor of Halemaʻumaʻu within the southern part of Kaluapele (Kīlauea caldera) may continue to exhibit slow movement or incandescence as they cool and solidify over the coming days. The Uēkahuna tiltmeter (UWD) recorded about 26.3 microradians of deflationary tilt during this episode. The end of the eruption was coincident with a rapid change from deflation to inflation at the summit and a decrease in seismic tremor intensity. Most episodes of Halemaʻumaʻu lava fountaining since the eruption started on December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days.
No changes have been detected in the East Rift Zone or Southwest Rift Zone. Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park. |
| (12) Volcanic cloud height: | Unknown |
| (13) Other volcanic cloud information: | Sulfur dioxide emission rate is typically 1,200-1,500 tonnes/day between eruptive episodes |
| (14) Remarks: | Hazard Analysis: This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/ Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Pumice and other volcanic fragments have fallen on Highway 11 west of Hawaiʻi Volcanoes National Park depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf Hawaiian 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 also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. 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. |
| (15) Contacts: | |
| (16) Next Notice: | HVO continues to closely monitor Kīlauea and will issue a VAN/VONA at the start of the next eruptive episode. If possible, HVO will also issue a Status Report beforehand at the onset of low-level precursory activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates More Information:
|
Episode 39 of the ongoing Halemaʻumaʻu eruption began at 8:10 p.m. HST on 23 December. Sustained lava fountains approximately 100 feet (30 meters) in height are currently erupting from both north and south vents. Fountain heights are currently increasing.
Past episodes have produced incandescent lava fountains over 1000 feet (300 meters) high that produce eruptive plumes up to 20,000 feet (6000 meters) above ground level. According to the National Weather Service, winds are blowing from the northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the southwest.
Episode 39 was preceded by overflows of degassed lava that began at approximately 6:41 p.m. from the south vent and continued to increase in intensity until 8:10 p.m., when sustained fountaining began.
Inflationary tilt reached just over 32 microradians since the end of the last episode. Seismic tremor began increasing and tilt at UWD switched from inflationary to deflationary at about 8:10 p.m. HST, about the same time lava flows began erupting onto the crater floor.
Most episodes of Halemaʻumaʻu lava fountaining since December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days.
No changes have been detected in the East Rift Zone or Southwest Rift Zone.
Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park.
Hazard Analysis:
This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/
Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Pumice and other volcanic fragments have fallen on Highway 11 west of Hawaiʻi Volcanoes National Park depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf
Hawaiian 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 also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. 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 a VAN/VONA at the start of the next eruptive episode. If possible, HVO will also issue a Status Report beforehand at the onset of low-level precursory 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
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20251224/0627Z) |
| (3) Volcano: | Kilauea (VNUM #332010) |
| (4) Current Color Code: | ORANGE |
| (5) Previous Color Code: | ORANGE |
| (6) Source: | Hawaiian Volcano Observatory |
| (7) Notice Number: | 2025/H555 |
| (8) Volcano Location: | N 19 deg 25 min W 155 deg 17 min |
| (9) Area: | Hawaii |
| (10) Summit Elevation: | 4091 ft (1247 m) |
| (11) Volcanic Activity Summary: |
Episode 39 of the ongoing Halemaʻumaʻu eruption began at 8:10 p.m. HST on 23 December. Sustained lava fountains approximately 100 feet (30 meters) in height are currently erupting from both north and south vents. Fountain heights are currently increasing. Past episodes have produced incandescent lava fountains over 1000 feet (300 meters) high that produce eruptive plumes up to 20,000 feet (6000 meters) above ground level. According to the National Weather Service, winds are blowing from the northeast direction, which suggests that volcanic gas emissions and volcanic material may be distributed to the southwest.
Episode 39 was preceded by overflows of degassed lava that began at approximately 6:41 p.m. from the south vent and continued to increase in intensity until 8:10 p.m., when sustained fountaining began. Inflationary tilt reached just over 32 microradians since the end of the last episode. Seismic tremor began increasing and tilt at UWD switched from inflationary to deflationary at about 8:10 p.m. HST, about the same time lava flows began erupting onto the crater floor. Most episodes of Halemaʻumaʻu lava fountaining since December 23, 2024, have continued for around a day or less and have been separated by pauses in eruptive activity lasting generally at least several days.
No changes have been detected in the East Rift Zone or Southwest Rift Zone. Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park. |
| (12) Volcanic cloud height: | Plume in past episodes has reached up to 20,000 feet (6000 meters) above ground level, driven by incandescent lava fountains over 1000 feet (300 meters) high |
| (13) Other volcanic cloud information: | Most volcanic ash and pumice (tephra) will fall within about 1 mile (1-2 km) of the eruptive vents. Lower concentrations of finer volcanic particles, such as ash and Pele's Hair, can be transported greater distances downwind of the vent (20 miles or 30 km). Sulfur dioxide emission rate is typically 50,000 tonnes/day during eruptive episode. |
| (14) Remarks: | Hazard Analysis: This episodic eruption is occurring within a closed area of Hawai'i Volcanoes National Park. High levels of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are one hazard of concern, as this hazard can have far-reaching effects downwind. As SO2 is continuously released from the summit during an eruption, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. SO2 and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/ Another hazard closer to the vent is fallout of Pele's hair and other volcanic fragments from lava fountains. Pele's hair is strands of volcanic glass often produced by lava fountaining activity and can be carried well over 10 miles (15 kilometers) from the vent. Other hot glassy volcanic fragments including Peleʻs hair, volcanic ash, pumice, scoria, and reticulite can fall on the ground within 1-2 miles (1-3 kilometers) of the eruptive vent(s) with the highest concentrations downwind of the vent(s). Pumice and other volcanic fragments have fallen on Highway 11 west of Hawaiʻi Volcanoes National Park depending on wind and eruption conditions. Strong winds may waft light particles, including Pele's hair, to greater distances downwind. Once they are on the ground, Pele's hair can sometimes cluster and tangle together, giving it the appearance of a tumbleweed. The extent of Pele's hair deposition is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other glassy volcanic fragments, which can cause skin and eye irritation. More information about how Pele's hair, its hazards, and what to do is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards. A recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.pdf Hawaiian 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 also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. 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. |
| (15) Contacts: | |
| (16) Next Notice: | HVO continues to closely monitor Kīlauea and will issue a VAN/VONA at the start of the next eruptive episode. If possible, HVO will also issue a Status Report beforehand at the onset of low-level precursory activity. Regularly scheduled daily updates for Kīlauea are posted on the HVO website at https://www.usgs.gov/volcanoes/kilauea/volcano-updates More Information:
|