Activity Summary: Around 9:15 a.m. HST this morning, January 15, 2025, the eruption of Kīlauea within Kaluapele (summit caldera) resumed with a small lava flow exiting the north vent, following low-level continuous lava spattering that started around 5:40 a.m. HST. from the same vent. Around 9:55 a.m., low-level lava fountaining started with more rigorous lava flow activity.

The small sluggish lava flow from the north vent at around 9:15 a.m. today, Wednesday January 15, 2025, marks the beginning of the fourth episode of the ongoing summit eruption. By 9:50 a.m., lava flow activity increased, and lava fountaining began around 9:55 a.m. At time of writing, approximately ten percent of the floor of Halemaʻumaʻu has been covered with new lava, and based on webcam imagery, the lava fountain appears to be 60 meters (200 feet) high. The sluggish, low effusion rate eruptive activity at the start of the fourth eruptive episode was shorter than the sluggish start of second (3-4 hours) and third (2.5 days) eruptive episodes. There are no signs of activity at the south vent.

The tiltmeter at Uēkahuna continued to record inflation beneath Halemaʻumaʻu starting around 9 a.m. yesterday, and may be starting to show signs of leveling off. Tremor increased when fountaining began, but is still lower than the first two episodes of vigorous high fountains (>250 feet or 80 meters).

If fountaining continues, it is possible that the fountain heights will increase as more gas-rich lava erupted. It is not possible to estimate how high the fountains may get or how long the fountaining will last, but prior episodes have produced fountains over 200 feet high (70 m) that last up to 24 hours.

This is the fourth episode of an eruption that began within Halemaʻumaʻu at the summit of Kīlauea volcano on December 23, 2024. Each episode of lava fountaining has continued for 14 hours to 8 days and episodes have been separated by pauses in eruptive activity lasting a less than 24 hours to 12 days. More details are available in the Information Statement that HVO published on January 10, 2025: https://volcanoes.usgs.gov/hans-public/notice/DOI-USGS-HVO-2025-01-10T20:11:29+00:00.  

HVO continues to closely monitor Kīlauea and will issue an eruption update tomorrow morning unless there are significant changes before then. HVO remains in close contact with Hawai‘i Volcanoes National Park and the Hawai‘i County Civil Defense Agency. Please see the Hawaiʻi Volcanoes National Park website for visitor information: https://www.nps.gov/havo/index.htm 

The Kīlauea summit livestream video is available here: https://www.youtube.com/usgs/live  

Kīlauea Volcano Alert Level/Aviation Color Code remain at WATCH/ORANGE. All current and recent activity is within Hawaiʻi Volcanoes National Park. No changes have been detected in the East Rift Zone or Southwest Rift Zone.

For more information about the meaning of volcano alert levels and aviation color codes, see https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes.  

The Kīlauea summit livestream video is available here: https://www.youtube.com/usgs/live 

Hazards

Eruptive activity is occurring at the base of the caldera within a closed area of Hawai'i Volcanoes National Park, which means that lava flows are not a hazard to infrastructure or the public. Resumption of eruptive activity is associated with increased emissions of volcanic gas. Sulfur dioxide (SO₂) in particular reacts in the atmosphere to create the visible haze known as vog (volcanic smog) downwind of Kīlauea. Vog and SO₂ are respiratory irritants, and even at low levels may affect sensitive individuals. 

Different areas may be affected by vog depending on emission rates and the local winds. Additional information about vog can be found at the resources below: 

• https://vog.ivhhn.org/  
• http://weather.hawaii.edu/vmap/new/  
• https://pubs.usgs.gov/fs/2017/3017/fs20173017.pdf  
• https://vog.ivhhn.org/vog-fact-sheets