USGS Volcano Notice - DOI-USGS-HVO-2025-02-22T17:11:21+00:00

Activity Summary:  

Kīlauea summit eruption paused as of 9:18 a.m HST on February 20.  A new eruptive episode is likely to begin in 1-5 days within Hawai'i Volcanoes National Park.

Episode 10 of the ongoing Halemaʻumaʻu eruption ended abruptly at 9:18 a.m. HST on February 20 after about 13 hours of eruptive activity. Kīlauea's current eruption in Halemaʻumaʻu crater within Kaluapele (the summit caldera) began on December 23, 2024. There have been 10 episodes of lava fountaining separated by pauses in activity. All eruptive activity remains within Hawai'i Volcanoes National Park. No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone.

Current hazards include volcanic gas emissions and windblown volcanic glass (Pele’s Hair) that may impact Hawai’i Volcanoes National Park and nearby communities.

Summit Observations:

Lava flows and fountains stopped erupting from the north vent within Halemaʻumaʻu crater at about 9:18 a.m. HST on February 20. Lava flows from episode 10 covered approximately 75% of the Halemaʻumaʻu crater floor. Spots of orange glow can still be seen on the crater floor at night as the erupted lava continues to cool. Both the north and south vents continue to degas and glow at night, but the glow visibly diminished on both the V1 and S2 cameras after midnight. 

Summit tilt changed rapidly from deflation to inflation, and seismic tremor decreased, at about the same time that the lava fountains stopped erupting on February 20. The Uēkahuna (UWD) tiltmeter has recorded approximately 4 microradians of inflationary tilt since the end of episode 10. Inflation has slowed to 1 microradian a day over the past 24 hours and began a slight deflation just after midnight last night. Seismic tremor decreased significantly at the end of episode 10 but remains above background. Seven small earthquakes were recorded at Kīlauea's summit over the past 24 hours. 

Volcanic gas emissions remain elevated. Based on measurements made during earlier episodes and pauses, sulfur dioxide (SO₂) emission rates are likely to be approximately 1,000 t/d during the current pause. An SO₂ emission rate of 2,100 t/d was measured at 11am on February 20.

Strands of volcanic glass known as Pele’s Hair have been reported on surfaces throughout the summit area of Hawai’i Volcanoes National Park and surrounding communities. 

• Summit eruption livestream: https://www.youtube.com/usgs/live
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams 

Rift Zone Observations:

Rates of seismicity and ground deformation remain very low in the East Rift Zone and Southwest Rift Zone with no significant earthquake activity in the past 24 hours. Sulfur dioxide (SO₂) emissions from the East Rift Zone remain below detection limit.

Analysis: 

The current eruption is marked by episodic fountaining not seen in any of the other Halemaʻumaʻu eruptions since 2020. Fountains and lava flows have erupted from two vents that we refer to as the north vent and south vent. The 10 fountaining episodes lasted from a few hours to over a week. Each fountaining episode has been accompanied by strong deflation of the summit region. Pauses between the fountaining episodes have been marked by an immediate change from deflation to inflation as the magma chamber recharges and repressurizes.

Analysis of inflationary tilt patterns prior to the onset of each fountaining episode allows a time window of probability for the onset of new episodes to be estimated. These are calculated using both minimum inflation necessary to start a new eruption and the rate of inflation. Current inflation of 1 microradian a day recorded at tilt station UWD in the past 24 hours is below rates of 1.5 to 2 microradians a day recorded during prior pauses. Low inflation rates coupled with weak deflation and diminished glow since midnight suggest that rise of magma in the vent has slowed and possibly even dropped slightly this morning.  Similar step-wise behavior has been recorded during the past 2 pauses with short periods of rapid inflation separated by longer periods of flat inflation or slight deflation.  Based upon the low inflation and prior behavior, the most likely window of time for a new episode to begin is late Sunday, February 23 to Thursday February 27.  If the inflation rate changes significantly, the likely window of the start of the next episode will be revised accordingly.

• Timeline of eruptive episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information
• Summit eruption reference map: January 15, 2025—Kīlauea summit eruption reference map | U.S. Geological Survey
• Volcano Watch article about Pele's Hair from this eruption: https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards

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.

Hazards: 

The eruption has been 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 the primary 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. Vog information can be found at https://vog.ivhhn.org/.

Additional hazards include Pele's hair and other volcanic fragments from lava fountains. Pele's hair are strands of volcanic glass often produced by lava fountaining activity. Volcanic fragments can fall on the ground within a few hundred yards (meters) of the eruptive vent(s), or on the western caldera rim downwind of the vent(s). Strong winds may waft light particles to greater distances downwind. Once they are on the ground, they can sometimes cluster and tangle together giving it the appearance of a tumbleweed. The extent of Pele's hair is dependent on lava fountaining activity and current wind conditions.  Residents and visitors should minimize exposure to these volcanic particles, which can cause skin and eye irritation. More information about how Pele's hair is formed is available here: https://www.usgs.gov/observatories/hvo/news/volcano-watch-peles-hairs-a-beautiful-hazard-island-hawaii. A Frequently Asked Questions document developed for the 2022 Mauna Loa eruption includes information about potential health effects of Pele's hair and is available here: https://vog.ivhhn.org/sites/default/files/FAQ_on_air_quality_and_health_during_Mauna_Loa_eruption_v1.6.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.

For discussion of Kīlauea hazards, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.