Kilauea fountained lava 500 feet high for nine hours in its 54th eruptive episode

Kilauea, the most active volcano in Hawaii, put on another dramatic display when its 54th eruptive episode sent lava fountains soaring roughly 500 feet into the air for about nine hours before the activity subsided. The episode began late in the morning of August 25 at the volcano’s summit and ended that evening, adding to a long-running pattern of intermittent lava fountaining that has characterized the summit eruption for more than a year and a half. Scientists monitoring the volcano say the eruption is not over but has entered another pause, with further episodes considered likely in the weeks ahead.

What happened during episode 54

The 54th episode of the ongoing eruption in Halemaumau crater began around 10:30 a.m. local time on August 25 and ended at 7:33 p.m. that evening, after roughly nine hours of continuous lava fountaining. The most vigorous activity came from the crater’s north vent, whose fountain reached a maximum height of about 500 feet, or 150 meters, above the ground. That peak was reached in the early afternoon, roughly two hours after the episode began, before the fountain gradually waned.

Neither the crater’s south vent nor a newer west vent fountained during the episode, leaving the north vent as the sole source of the towering jets of molten rock. The eruption also produced a volcanic plume that rose to approximately 17,000 feet above sea level, carrying gas and fine volcanic particles high into the atmosphere over the summit region.

Where the volcanic material fell

Most of the debris thrown out by the fountains stayed within a closed section of Hawaii Volcanoes National Park, southwest of the active vents, according to the U.S. Geological Survey’s status report on the episode. The material included volcanic ash and lightweight glassy fragments generated by the fountaining, which winds can carry varying distances depending on their size.

Observers did record a report of trace amounts of Pele’s hair, thin strands of volcanic glass formed when molten lava is stretched by the wind, falling in the Kau district of the island. Such fine glass fragments can travel well beyond the vents during fountaining episodes and can cause skin, eye and respiratory irritation, prompting officials to advise residents and visitors downwind to limit their exposure.

A summit eruption more than a year in the making

Episode 54 is the latest chapter in an eruption that has unfolded in fits and starts since it began on December 23, 2024. Over that span, Kilauea has erupted episodically from two vents in Halemaumau, with each fountaining episode generally lasting less than 12 hours and separated by pauses of two or more weeks. That rhythmic, on-again, off-again behavior has made the summit a compelling and closely watched spectacle for scientists and the public alike.

The U.S. Geological Survey’s Hawaiian Volcano Observatory has tracked each episode in detail, maintaining a running record of the eruption and its evolving vents. The agency’s eruption information chronicles the timeline of episodes since the eruption began, documenting how the fountaining has migrated among vents and varied in intensity from one episode to the next.

Why another episode is expected

Rather than signaling the end of the eruption, the close of episode 54 set the stage for what is likely to come next. Almost immediately after the fountaining stopped, instruments detected the summit beginning to reinflate as fresh magma accumulated beneath the surface, a strong indicator that pressure is rebuilding toward another episode. Glow remained visible overnight from vents within the crater, another sign that molten rock lingers close to the surface.

Monitoring data showed a substantial amount of deflation during the episode itself, followed by a swing back toward inflation once it ended, though scientists noted the pattern has been irregular and difficult to forecast precisely. The observatory said more measurements of that inflationary trend would be needed before it could pin down a timing window for the next episode, but it assessed that another bout of fountaining is likely in the coming weeks.

The hazards that persist between episodes

Even when Kilauea is not actively fountaining, it continues to pose hazards concentrated around the summit. The volcano releases high levels of volcanic gas, chiefly water vapor, carbon dioxide and sulfur dioxide, and the sulfur dioxide reacts in the atmosphere to create a haze known as vog that can drift downwind and cause respiratory problems at high concentrations. During pauses between episodes, the summit’s sulfur dioxide emission rate typically varies between roughly 1,000 and 5,000 tonnes per day.

Other dangers include unstable crater walls, ground cracking and rockfalls, along with lava that remains hot and can slowly move for days after an episode ends. Because of those risks, the area immediately around Halemaumau has been closed to the public since 2007, and the current episodic eruption has been occurring within that closed zone of the national park.

How officials are tracking the volcano

Throughout the eruption, the Hawaiian Volcano Observatory has kept Kilauea under close watch, coordinating with the national park and county civil-defense officials on eruptive hazards. As of the days following episode 54, the volcano’s alert level stood at advisory and its aviation color code at yellow, reflecting an eruption that is significant but currently paused. The agency’s regularly issued volcano updates continued to report on summit conditions, noting that another fountaining episode could develop once the pattern of reinflation matured. For now, Kilauea sits between acts, its 54th episode logged in the record and its 55th anticipated but not yet scheduled.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

More from Morning Overview