Kilauea's 38th Eruption Episode Features Rare Triple Lava Fountain

Kilauea volcano, one of the most active shield volcanoes on Earth located on Hawaii Island, concluded its 38th eruptive episode on December 6, 2025. This event continues the intermittent summit eruption sequence that began on December 23, 2024, within the Halemaʻumaʻu crater. The most recent episode persisted for approximately 12.1 hours and was scientifically notable for the rare simultaneous eruption from three distinct vents inside the Halemaʻumaʻu crater.

The geophysical dynamics involved two vents within the north cone and one south vent initiating fountaining. Activity began with sustained lava fountains from the north vents at 8:45 a.m. HST, followed by the south vent joining at 8:49 a.m. By 9:15 a.m. HST, the triple fountain was fully established, with all three sources ejecting material to heights near 500 feet (150 meters). The south vent subsequently intensified, producing inclined lava fountains that reached nearly 1,200 feet (370 meters), a height last recorded during Episode 24 on June 5, 2025.

This peak effusion rate, estimated at 1,300 cubic yards per second just before 10:00 a.m. HST, drove a substantial plume ascending to approximately 15,000 feet (4,500 meters) above sea level, carrying significant sulfur dioxide (SO2) emissions. Earlier in the event, the gas plume had reached over 20,000 feet (6,000 meters), resulting in tephra, including Pele's hair, falling in communities southwest of the vents, such as Pahala. The intense energy release from the south vent caused immediate physical consequences within Hawaiʻi Volcanoes National Park when ejected material destroyed the U.S. Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) V3 summit livestreaming camera site shortly before 10:00 a.m. HST.

The episode concluded abruptly at 8:52 p.m. HST when the south vent ceased activity, while the north vents stopped erupting earlier at approximately 11:50 a.m. The Uēkahuna tiltmeter recorded approximately 33.1 microradians of deflationary tilt during the episode, which coincided with a rapid shift from deflation to inflation at the summit and a decrease in seismic tremor intensity. The USGS maintained the Volcano Alert Level at WATCH and the Aviation Color Code at ORANGE, confirming that all eruptive manifestations remained strictly confined within the boundaries of Hawaiʻi Volcanoes National Park, posing no impact to commercial airports.

The lava flows generated during this 12.1-hour event covered an estimated 50% to 60% of the Halemaʻumaʻu Crater floor. This pattern of episodic fountaining, often lasting less than a day and separated by pauses, has characterized the eruption sequence that commenced in December 2024 for the Kilauea volcano, which is between 210,000 and 280,000 years old.