USGS Volcano Notice - DOI-USGS-HVO-2025-03-19T20:13:37+00:00

Activity Summary:  

Episode 14 of the ongoing Halema'uma'u eruption of Kīlauea volcano began continuous lava effusion from the north vent at 9:26 a.m. HST March 19 in Hawai'i Volcanoes National Park. Precursory activity of seven small, short-lived lava flows erupted between midnight and 6:00 a.m. HST. Continuous eruptions of lava began at the north vent at 9:26 a.m. HST followed by lava overflowing the south vent at about 9:50 a.m. HST.  Low dome fountaining is intermittently present as gas rich magma starts to mix with the degassed magma.  High fountains should begin within the next several hours.

Each episode of Halemaʻumaʻu lava fountaining since December 23, 2024, has continued for 13 hours to 8 days and episodes have been separated by pauses in eruptive activity lasting less than 24 hours to 12 days.

Kīlauea's current eruption in Halemaʻumaʻu crater within Kaluapele (the summit caldera) began on December 23, 2024. There have been 13 episodes of lava fountaining separated by pauses in activity. Episode 13 ended at 3:13 p.m. HST on March 11. 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.

Summit Observations:

Small, degassed lava flows began erupting continuously from both vents within Halemaʻumaʻu crater beginning at 9:26 a.m. HST from the north vent and 9:50 a.m. HST from the south vent. The occasional spatter bursts in both cones slowly waned throughout the morning after 7:00 a.m. HST, but activity in both cones picked back up around 9:20 a.m. HST just prior to the start of continuous eruption. The south vent flows shut off around 10:35 a.m. HST.  Cyclic low dome fountains have been alternating with short drainbacks every 5-10 minutes with the interval decreasing over time.  Maximum dome fountains are 30 feet high (10 meters) and are occurring within a 200 foot by 150 foot  (65 by 45 meters) lava pond that drops about 5-10 feet (2-3 meters) during each drainback event within the north cone.  Fountain heights are expected to grow within the next several hours as gas-rich magma increases as the denser, degassed lava is erupted from the vent.

The start of episode 14 was preceded by seven small, short-lived, sluggish lava flows that began overflowing the south vent just before midnight. The first flow was active from 23:58 p.m. HST March 18 to 00:02 a.m. HST March 19 and the second from 00:56 to 1:03 a.m. HST. These were followed by a third tongue of lava from the south vent from 1:57 to 2:01 a.m. HST and a fourth from 3:36 to 3:46 a.m. HST.  The fifth and sixth sluggish lobes erupted from 4:20 a.m. to 4:28 a.m. HST and 5:04 to 5:14 a.m. HST. A seventh short-lived flow erupted from the south vent between 6:02 a.m. and 6:10 a.m. HST March 19. This flow was accompanied by large spatter bursts from the south vent that could be seen over the top of the north cone on the V1 camera. None of the seven flows lasted more than 10 minutes nor went more than about 50 feet (15 meters) from the south vent. Occasional spatter bursts could be seen in the north vent on the V1 camera throughout the night and becoming more frequent in the early morning hours. The small overflows and spattering from both vents indicated that magma was very near the surface in the early morning hours. 

The rate of summit inflationary tilt has plateaued over the past 24 hours. The Uēkahuna (UWD) tiltmeter has recorded just over 11 microradians of inflationary tilt since the end of episode 13. The UWD tiltmeter had to be reset Friday March 15 creating a small offset in the data. Seismic tremor decreased significantly at the end of episode 13 but remains above background.

An SO₂ emission rate of 1,200 t/d was measured on March 18, which is a typical rate for eruption pauses. As the eruption continues gas emissions are expected to increase dramatically as well as the production tephra such as pumice and Pele's hair that can be transport long distances downwind from the vents.

• 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 13 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.

Eruption of degassed lava is underway, high fountains should begin within the next several hours.

• 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 downwind of the vent(s). 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 is dependent on lava fountaining activity and current wind conditions. Residents and visitors should minimize exposure to Pele's hair and other 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 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.