HAWAIʻI VOLCANOES NATIONAL PARK – The Hawaiian Volcano Observatory (HVO) / USGS has announced the commencement of Episode 27 of Kīlauea volcano’s ongoing Halemaʻumaʻu eruption. This new phase began at 9:05 a.m. HST today, June 29, 2025, marked by a significant increase in vigor of the lava fountains from the north vent.
Currently, these lava fountains are reaching impressive heights of approximately 500 feet (150 meters), feeding multiple lava streams that are flowing across the crater floor. HVO anticipates that fountain heights could increase further in the coming hour.
The current Volcano Alert Level remains at WATCH, and the Aviation Color Code is ORANGE. All current and recent volcanic activity is contained within Hawaiʻi Volcanoes National Park, which is largely a closed area.
Key Observations and Hazards:
- Eruption Onset: Episode 27 was preceded by smaller, sporadic dome fountains in the north vent, which began at approximately 7:27 a.m. HST and progressively intensified.
- Seismic and Tilt Activity: Seismic tremor increased, and tilt at station UWD switched from inflationary to deflationary around 7:30 a.m. HST, coinciding with the onset of lava flows.
- Typical Episode Duration: Most Halemaʻumaʻu lava fountaining episodes since December 23, 2024, have lasted roughly a day or less, typically followed by pauses of several days.
- Gas Emissions: Volcanic gas emissions are the primary concern. The sulfur dioxide emission rate is typically 50,000 tonnes/day during sustained fountaining. This continuously released SO2 reacts in the atmosphere to create vog (volcanic smog) downwind, which can cause respiratory and other health problems at high concentrations. More information on vog is available at https://vog.ivhhn.org/.
- Tephra and Pele’s Hair: Additional hazards include Pele’s hair (strands of volcanic glass) and other small volcanic fragments produced by the fountaining. These particles can fall within a few hundred yards of the vent or be carried downwind by strong winds. Residents and visitors should minimize exposure to these materials, which can cause skin and eye irritation. Information on Pele’s hair hazards can be found at https://www.usgs.gov/observatories/hvo/news/volcano-watch-recent-lava-fountains-highlight-peles-hair-hazards.
- Wind Uncertainty: According to the National Weather Service, winds are generally from the northeast to east, but field observations suggest variability. Therefore, the exact distribution direction of volcanic gas emissions and tephra around Halemaʻumaʻu is uncertain at this time.
- Lava Flow Confinement: All lava flows are currently confined to Halemaʻumaʻu crater (within the summit caldera).
- No East or Southwest Rift Zone Changes: No changes have been detected in Kīlauea’s East Rift Zone or Southwest Rift Zone.
- Other Hazards: Significant hazards persist around Kīlauea caldera, including crater wall instability, ground cracking, and rockfalls, which can be exacerbated by earthquakes within the public-restricted area.
HVO will issue a new VAN/VONA (Volcano Activity Notice/Volcano Observatory Notice for Aviation) when sustained lava fountaining ceases, the eruption pauses, or earlier if conditions warrant an update.
For a timeline of eruptive episodes since December 23, 2024, visit: https://www.usgs.gov/volcanoes/kilauea/science/eruption-information Three Kīlauea summit livestream videos are available here: https://www.youtube.com/@usgs/streams For more information on Kīlauea hazards, please see: https://www.usgs.gov/observatories/hawaiian-volcano-observatory/hazards.