Activity Summary:

The ongoing Halema'uma'u eruption is paused. Episode 27 began and ended on June 29 at 7:54 p.m. HST after nearly 11 hours of sustained lava fountaining. The end of the episode was coincident with a change from deflationary tilt to inflationary tilt at the summit, along with a decrease in seismic tremor intensity. Summit inflation continues this morning, along with persistent, low level seismic tremor, suggesting another episode is possible. However, more time and data are needed before a forecast window can be made for episode 28. 

Lava fountaining episodes have occurred approximately once per week since the start of the 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 and windblown volcanic glass (Pele’s hair) and tephra deposited during past episodes in the Kīlauea summit region of Hawaiʻi Volcanoes National Park and nearby communities.

Summit Observations:

Episode 27 lava fountaining was preceded by about 24 hours of intermittent precursory low-level activity that included small, sporadic lava spattering and jetting as well as lava overflows from the north vent. At 7:27 a.m. on June 29, another overflow resulted from low dome fountains within the north vent. Small but sustained lava fountaining began at 8:03 a.m. and grew slowly until 9:03 AM when height and vigor increased dramatically. High fountains began around 9:05 a.m. in association with an accelerated transition to deflationary tilt and an increase in seismic tremor. Over the next few hours, north vent fountains reached heights of at least 1,100 feet (340 meters) before gradually declining for the remainder of the episode. South vent fountains began erupting by 3:00 p.m., but remained relatively low throughout the episode. Both vents shut down abruptly at 7:54 p.m. on June 29, though flames were visible at the south vent for a few minutes afterwards.

Approximately 1.6 billion gallons (8.1 million cubic yards, 6.2 million cubic meters) of lava erupted during the sustained fountaining phase of episode 27. These lava flows covered 80% of the Halemaʻumaʻu crater floor within the southern part of Kaluapele (Kīlauea caldera). These lava flows may continue to exhibit slow movement or incandescence as they cool and solidify over the coming days.

The eruptive plume from episode 27 reached at least 20,000 feet (6,000 meters) above ground level during episode 27. Sulfur dioxide (SO₂) emissions could not be directly measured; however, typical values observed for past fountaining episodes have ranged from 50,000-75,000 tonnes/day. The average SO₂ emission rate during inter-episode pauses, such as the current pause, is typically around 1,200 tonnes/day.

Episode 27 was accompanied by approximately 16 microradians of deflationary tilt at the tiltmeter near Uēkahuna (UWD), which was about 2 microradians less than the amount of deflationary tilt recorded during episode 26. The end of episode 27 was coincident with a change from deflationary tilt to inflationary tilt at the summit and a decrease in seismic tremor intensity. UWD has recovered around 3 microradians of inflationary tilt in the 11 hours since the end of episode 27. Seismic tremor has returned to slightly elevated levels beneath Halemaʻumaʻu crater.

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.

• Eruption resources, including the most recent map and a timeline of eruption episodes since December 23, 2024: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information 
• Three Kīlauea summit livestream videos are available here: Kīlauea Volcano, Hawaii (West Halemaʻumaʻu crater) v1cam, Kīlauea Volcano, Hawaii (East Halemaʻumaʻu crater) v2cam, and Kīlauea volcano, Hawaii (South Halemaʻumaʻu crater) v3 cam
• Summit eruption webcams: https://www.usgs.gov/volcanoes/kilauea/summit-webcams 

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: 

Additional time is needed to accumulate tiltmeter data before a forecast window can be made for episode 28. However, given that the deflationary tilt during the past several episodes was similar, we expect a roughly similar pause duration following episode 27. The pause between the past several recent episodes ranged from 6 to 10 days.  

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.