Activity Summary:
The ongoing Halemaʻumaʻu eruption is paused. Episode 27 ended on June 29 at 7:54 p.m. HST after nearly 11 hours of sustained lava fountaining. The end of the fountaining episode coincided with a change from deflationary tilt to inflationary tilt at the summit, along with a decrease in seismic tremor intensity. Summit inflation continues at this time, along with persistent, low-level seismic tremor. Additionally, incandescent glow has returned to the north vent in overnight webcam views. These observations indicate that another fountaining episode is likely, with the current summit inflation rate suggesting it will occur sometime between July 7 and 12. This window is subject to change due to variations in the summit inflation rate and other factors, and it will be refined as more data become available.
Fountaining episodes have occurred approximately once per week since the start of the current eruption on December 23, 2024. All eruptive activity remains within Hawaiʻi Volcanoes National Park. No significant activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone. Current hazards include ongoing volcanic gas emissions, along with windblown volcanic glass (Pele’s hair) and tephra deposited during past fountaining episodes in the Kīlauea summit region of Hawaiʻi Volcanoes National Park and nearby communities.
Summit Observations:
Incandescent glow was visible at the north vent in Halemaʻumaʻu crater overnight. Lava flows from episode 27 on the floor of Halemaʻumaʻu within the southern part of Kaluapele (Kīlauea caldera) continue to exhibit minor incandescence as they cool and solidify. Episode 27 began around 9:05 a.m. on June 29 and ended at 7:54 p.m. the same day. Lava fountains from the north vent reached heights of up to about 1,100 feet (340 meters) during episode 27.
The tiltmeter near Uēkahuna (UWD) has recorded more than 6 microradians of inflationary tilt since the end of episode 27. UWD recorded more than 16 microradians of deflationary tilt during episode 27. Seismic tremor continues at slightly elevated levels beneath Halemaʻumaʻu crater.
Vigorous degassing also continues from both the north and south vents. The average Sulfur dioxide (SO2) emission rate during inter-episode pauses, such as the current pause, is typically around 1,200 t/d.
Strands of volcanic glass known as Pele’s hair are present throughout the summit area of Hawaiʻi Volcanoes National Park and surrounding communities and can be remobilized by wind.
The KW webcam was restored June 24, along with the laser rangefinder instrument that measures the surface of the lava lake. KW cam images are once again available online at https://www.usgs.gov/media/webcams/kwcam-halemaumau-and-down-dropped-caldera-floor-west-rim-summit-caldera-looking. On June 27, the F1 thermal webcam and B1 webcam were also restored, with their respective images available at https://www.usgs.gov/volcanoes/kilauea/f1cam-halemaumau-thermal-image-west-rim-summit-caldera-looking-southeast and https://www.usgs.gov/volcanoes/kilauea/b1cam-kilauea-caldera-down-dropped-block-and-halemaumau.
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 the detection limit.
Analysis:
The new forecast window for the start of episode 28 lava fountaining is sometime between July 7 and 12 based on the current rate of summit inflation. This window is subject to change due to variations in summit inflation rate and other factors, and it will be refined as more data become available. Episode 28 fountaining will likely be preceded by hours to days of sustained precursory activity such as lava spattering and small lava flows at the eruptive vent(s).
The current eruption has been characterized by episodic lava fountaining not seen in any eruptions since the 1983–86 episodic fountains at the beginning of the Puʻuʻōʻō eruption. Lava fountains and flows have erupted from two vents within Halema'um'a'u crater that we refer to as the north vent and south vent. Each of the previous fountaining episodes lasted from a few hours to over a week and was 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. Fountaining episodes have occurred approximately once per week since the start of the eruption.
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:
This episodic eruption is occurring within a closed area of Hawaiʻi 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 forms, 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 recently updated Frequently Asked Questions document that includes information about potential health effects of Pele's hair is available here: https://vog.ivhhn.org/sites/default/files/PelesHair_FAQs_v2.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.
The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi and American Samoa.
