USGS Volcano Notice - DOI-USGS-HVO-2025-02-26T16:50:44+00:00

Activity Summary:  

Episode 11 of the Kīlauea summit eruption paused today at 7:06 a.m. HST on February 26 within Hawai'i Volcanoes National Park after erupting for 12 hours and 44 minutes.

Episode 11 of the ongoing Halemaʻumaʻu eruption began at 6:22 p.m. HST on February 25 and fountains reached peak heights of around 600 feet (180 m) 1-2 hours later. Kīlauea's current eruption in Halemaʻumaʻu crater within Kaluapele (the summit caldera) began on December 23, 2024. There have been 11 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 south vent within Halemaʻumaʻu crater at about 7:06 a.m. HST on February 26. Lava flows from episode 11 covered approximately 75%-80% of the Halemaʻumaʻu crater floor. and sent lava flows onto the down dropped block around the September 2023 vents. Both the north and south vents continue to degas. The north vent began erupting at 6:22 p.m. HST last night February 25 with low fountains.  Over the next hour the fountains grew in height to approximately 600 feet (180 m).  Small spatter fountains began at the south vent just before 7 p.m. HST and by 8 p.m. HST were producing small flows.  The south vent fountains and flows increased in size by 9:00 p.m. HST and continued fountaining together until 6:35 a.m. HST on February 26 when fountaining stopped at the north vent.  The south vent fountains began to drop at this time and by 7:06 a.m. HST lava fountaining and flows stopped at the south vent marking the end of Episode 11.  

The onset of episode 11 was preceded by the appearance of glow along the row of September 2023 vents on the east side of Halemaʻumaʻu crater.  The glow began at one cone on the evening of February 24 and became visible along the entire 2023 fissure around 6 p.m. HST on February 25. Glow on the 2023 fissure remained persistent through much of the night.  This suggests that magma within the vent system may have intruded into the molten interior of Halemaʻumaʻu crater prior to the onset of episode 11.  Similar glow was not observed along the 2023 vents prior to or during episode 10.

Large amounts of pumice, Peleʻs hair, and lighweight reticulite were deposited up on the west rim of Halemaʻumaʻu crater last night blanketing the area.  A few light weight "ribbon" bombs up to about 1-2 feet (0.3-0.6 m) were also found on top of the pumice.

Summit tilt changed rapidly from inflation to deflation at the onset of the eruption (6:22 p.m. HST February 25) and dropped about 10 microradians during the eruption.  Tilt turned back to inflation at 6:35 a.m. HST February 26 when fountaining at the north vent stopped.  Seismic tremor increased rapidly at the onset of the eruption and decreased sharply when the north vent fountains stopped and returned to the high background levels when the fountaining at the south vent stopped a half an hour later.   The Uēkahuna (UWD) tiltmeter has recorded less than 0.5 microradians of inflationary tilt since the end of episode 11.  No seismicity was 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. There has not been enough time to establish if and when another episode will be most likely to begin.

• 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.