Kilauea Volcano (Hawai'i): Fourth Effusive Episode Begins with Intense Lava Fountains

This morning at approximately 9:15 AM local time, a sluggish lava flow from the north vent marked the start of the fourth episode of the ongoing summit eruption. By 9:50 AM, the activity escalated, with lava fountains beginning around 9:55 AM. Currently, fresh lava covers an estimated 10 percent of the Halemaʻumaʻu crater floor. Webcam footage shows vigorous lava fountains reaching heights of about 60 meters (200 feet).

The initial sluggish, low-effusion activity of this fourth episode was shorter compared to the second episode, which lasted 3-4 hours, and the third episode, which took 2.5 days to intensify. No activity has been observed at the south vent.

The Hawaiian Volcano Observatory reported: "The tiltmeter at Uēkahuna has been recording inflation beneath Halemaʻumaʻu since around 9 AM yesterday and may now be showing signs of stabilizing. Tremor levels increased with the onset of fountaining, but remain lower than those observed during the first two episodes, which featured vigorous fountains exceeding 250 feet (80 meters)."

“Scientists from the USGS Hawaiian Volcano Observatory report the continuation of Kīlauea's ongoing eruption during its fourth eruptive episode. The eruption, which had paused since January 3, 2025, resumed on January 15, 2025. As of today, January 16, 2025, the south fountain averages a height of about 40 meters (131 feet), while the north fountain fluctuates between 50 and 60 meters (164–197 feet). Fountain heights have decreased slightly from yesterday's peak measurements of 90–100 meters (295–328 feet).”

By midday Wednesday, two vents within the summit caldera remained active, with lava fountains continuing overnight. On Thursday, parts of the south vent collapsed. Lava flow activity has been confined to the southwest crater floor near the active vents.

Seismic tremor in the summit region, which began with the onset of this fourth episode, remains high, indicating ongoing eruptive activity.

Sulfur dioxide emissions surged to approximately 10,000 tonnes per day at the start of the new episode.

If the fountaining continues, fountain heights may increase as more gas-rich lava erupts. The exact height and duration of the fountains remain uncertain, though previous episodes have produced fountains over 200 feet (70 meters) tall, lasting up to 24 hours.