Kīlauea's Swelling Summit Shows When Its Next Lava Fountain Will Begin

The U.S. Geological Survey's Hawaiian Volcano Observatory reported on Oct. 8, 2026, in Science that the amount Kīlauea's summit swells between bursts of lava tracks when the next burst begins, a correlation the team used to forecast the start of individual episodes.

The paper presents a monitoring record of the eruption that combines chemical, geophysical and geologic measurements. Several mechanisms have been proposed for episodic fountaining, and the authors report that basic questions remain about what sets off each episode, among them the pressure in the magma reservoir under the crater and the gas separating out of the molten rock.

Inside the summit crater Halemaʻumaʻu, the eruption began in December 2024 and had produced 54 fountaining episodes by the time the paper appeared, each typically lasting hours and separated by gaps of days to weeks. Episodes of this kind are rare worldwide, with only three at Kīlauea since 1823.

A. F. Flinders of the Hawaiian Volcano Observatory is the first author, and co-authors are based at the USGS Cascades and California Volcano Observatories, the University of Hawaiʻi at Hilo and at Mānoa, Earth Sciences New Zealand and the University of Oregon.

The team says the ongoing eruption will provide new constraints on the timing, evolution and processes behind episodic fountaining worldwide, and describes Kīlauea as a natural laboratory for studying how volcanoes work.