Newest Volcano Notice Including Kilauea

Activity Summary:  

The ongoing Halemaʻumaʻu eruption is paused; episode 17 ended at 9:45 a.m. HST on April 9 when low fountaining at the south vent stopped. The south vent continues to de-gas and glow weakly at night. If the eruptive activity reverts to pre-episode 17 behavior, data indicate that episode 18 is likely to begin in the next 2-4 days.

Kīlauea's current eruption in Halemaʻumaʻu crater within Kaluapele (the summit caldera) began on December 23, 2024. There have now been 17 episodes of 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) and tephra that have impacted Hawai’i Volcanoes National Park and nearby communities.

Summit Observations:

The south vent had a faint glow for most of the night with short periods of moderate glow. Degassing is currently only occurring from the south vent.

Low lava fountaining began the night of April 7 at the south vent around 10:15 p.m. HST and started to produce a small lava flow that spread across the crater floor. During episode 17 sustained fountains ranged from about 50 feet (15 meters) high to bursts up to 200 feet (60 meters) from primarily the south vent with a short period of minor fountaining at the north vent. At 9:45 a.m. HST on April 9, fountaining from the south vent stopped, marking the end of episode 17. During this episode, lava flows covered over 40-50% of the floor of Halemaʻumaʻu within the southern part of Kaluapele (Kīlauea caldera). Additional details about the eruption were posted earlier in the April 8 Status Report, the April 8 Daily Update for Kīlauea, the April 9 Daily Update for Kīlauea, and the April 9 Status Report.

The UWD and SDH tiltmeters show a distinct change in tilt from deflationary to inflationary trending that is coincident with the end of episode 17. As of this morning, UWD has measured a little less than 6.5 microradians of inflationary tilt since 9:45 a.m. HST April 9. Seismic tremor rapidly dropped in intensity on April 9 at 9:45 a.m. HST when episode 17 ended and continues at low levels.

Volcanic gas emissions remain elevated and at heightened levels due to lava fountaining. The last sulfur dioxide (SO₂) emission rate measured on April 10 was approximately 1,200 tonnes per day. Typical levels of Sulfur dioxide (SO₂) emission have been about 1,000 tonnes per day during previous pauses. This morning, the plume is being carried towards the southwest. 

Strands of volcanic glass known as Pele’s Hair from previous episodes are still present throughout the summit area of Hawai’i Volcanoes National Park and surrounding communities and can be remobilized by wind if present. 

• Timeline of eruption episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information 
• Two Kīlauea summit livestream videos are available here: Kīlauea Volcano, Hawaii (West Halemaʻumaʻu crater) v1cam and Kīlauea Volcano, Hawaii (East Halemaʻumaʻu crater)v2cam
• 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 has been characterized 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. Each of the previous 16 fountaining episodes lasted from a few hours to over a week and 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 fit to data derived from past eruptive episodes. The onset of episode 17 occurred earlier than forecasted, as the fountaining began prior to the tilt rebounding to the expected threshold that had been previously associated with episode onsets. If the eruption returns to pre-episode 17 inflation behavior, data suggest episode 18 will likely begin between Monday and Wednesday of next week, 2-4 days from now. This window may be adjusted if inflation rates change significantly.  

• 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.

General Updates: 

The power system that supplies power to the KWcam webcamera, the F1cam thermal camera, and the laser rangefinder sustained damage during the high fountaining on March 26, 2025. Both cameras and the rangefinder are currently offline. Other HVO webcameras are still functioning and online.

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 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. SO₂ and vog may cause respiratory and other problems at high concentrations. Further information on vog can be found at https://vog.ivhhn.org/

Additional hazards include Pele's hair and other volcanic fragments from lava fountains. Pele's hair is 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 deposition 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.