Kīlauea's swelling summit helps scientists forecast lava fountain eruptions

October 9, 2026 report Kīlauea's swelling summit helps scientists forecast lava fountain eruptions Krystal Kasal Author Gaby Clark Scientific Editor Robert Egan Senior Editor Episodic lava fountaining is a rare volcanic behavior in which repeated, hours-long bursts of molten lava and gas are spewed from volcanic vents, with quiet pauses lasting days to weeks between episodes. These lava fountains have been observed in active volcanoes in places like Hawaii, Iceland and Italy, but researchers still do not fully understand what starts, sustains or stops these individual fountain episodes. In a new study, published in Science, a team of geologists analyzed data from a recent record-breaking lava fountain sequence from Hawaii's Kīlauea volcano. The team's analysis is improving predictions of when these lava fountains will occur, leading to forecasts that can help communicate eruption-related hazards to nearby communities and park staff. Kīlauea's record-breaking fountain sequence Before 2024, Kīlauea had only three documented lava fountaining sequences. But in late 2024, Kīlauea began a new sequence that, as of September 2026, has produced 54 episodes. This is the most lava fountaining episodes recorded during any Kīlauea eruption. While many of the fountains reached only around 100 meters (330 feet), the highest have reached about 480 meters (1,570 feet). Windblown volcanic fragments from the fountains have affected roads, park infrastructure and communities up to about 70 kilometers (43 miles) away. Since the eruptions are situated in an easily accessible area of Hawaiʻi Volcanoes National Park (HAVO) with a regular livestream of the events, they have drawn much attention. The Hawaiian Volcano Observatory (HVO), which runs the livestream, has since added two more. The authors of the new study write, "Although the livestreams reached a global audience, they were used most heavily by Hawaii residents, particularly those on the island of Hawaiʻi, where per capita viewership far exceeded that of any other region, highlighting the webcams' value as a near-real-time communication tool for local communities. "Notably, on December 6, 2025 (episode 38), shallow collapse of the south vent produced a south-inclined fountain, burying one of HVO's livestream webcams under 10 m (33 feet) of agglutinated spatter, ∼630 m (2,070 feet) away. A video clip of the webcam being destroyed was viewed more than 500,000 times across social media platforms." New monitoring methods lead to better predictions and understanding The research team says this is the first Kīlauea eruption tracked by a dense, modern monitoring network, offering a chance to test some of the competing explanations for how the fountains start and stop. The leading explanation involves rising magma releasing water-rich gas bubbles near the surface, accelerating lava out of the vent. Another potential explanation is that carbon dioxide–rich foam builds up inside a magma reservoir and collapses, driving the fountains. To look for relevant patterns, the researchers combined ground movement, seismic, low-frequency sound, gas, satellite and camera observations from the first 39 episodes. They also analyzed erupted rock and volcanic glass to track changes in magma composition. Results showed that the summit slowly swelled between episodes and rapidly deflated during fountaining, consistent with pressure building and falling in a shallow magma reservoir. The team noticed that fountains repeatedly began near recognizable, gradually changing ground-tilt thresholds. These patterns enabled useful forecasts despite little increase in earthquake activity before most episodes. While the patterns can't provide exact eruption times, they can help forecast time windows. Analysis also showed that lava chemistry changed over months, indicating periodic arrivals of hotter magma. No clear chemical changes occurred in individual fountain episodes. But from episode 14 onward, magma commonly rose and drained back repeatedly before sustained fountaining, indicating shallow gas accumulation and release. These preliminary gas observations seem to be more consistent with the shallow, water-rich bubble explanation than with the deeper carbon dioxide–rich foam explanation. However, more observations are needed to settle the debate completely. The study authors write, "The eruption's outcome remains unknown. Continued monitoring will help constrain how magma and gas recharge, reservoir pressure, conduit connectivity and permeability, and volatile segregation and outgassing produce episodic fountaining, while underscoring Kīlauea's fundamental role as a globally accessible natural laboratory for developing new techniques in volcano monitoring and eruption forecasting." Written for you by our author Krystal Kasal, edited by Gaby Clark, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you. Publication details A. F. Flinders et al, Insights from more than a year of ongoing episodic lava fountaining at Kīlauea, Science (2026). DOI: 10.1126/science.aef2931 Journal information: Science © 2026 Science X Network