Kīlauea's swelling summit helps scientists forecast lava fountain eruptions

Kīlauea's swelling summit has been a key factor in scientists' ability to forecast lava fountain eruptions, according to a new study published in Science. The research team analyzed data from a record-breaking sequence of fountaining episodes at Hawaii's Kīlauea volcano, which produced 54 episodes by September 2026. This is the highest number of episodes ever recorded during any Kīlauea eruption.

Episodic lava fountaining is a rare volcanic behavior characterized by repeated, hours-long bursts of molten lava and gas from volcanic vents, with quiet pauses lasting days to weeks between episodes. While researchers understand the general behavior, the specific triggers for starting, sustaining, and stopping these fountains remain unclear. The new study improves predictions of when these fountains will occur, helping to communicate eruption-related hazards to nearby communities and park staff.

The study found that Kīlauea's summit inflated slowly between episodes and rapidly deflated during fountaining, consistent with pressure changes in a shallow magma reservoir. Ground tilt thresholds near recognizable levels seemed to trigger recurring fountains, enabling forecasts of eruption windows, even without significant increases in earthquake activity.

Preliminary gas observations suggested shallow, water-rich bubble release as the more likely explanation for fountaining onset, rather than deeper carbon dioxide-rich foam collapse.

However, more observations are needed to fully settle the debate. The eruption's outcome remains unknown, but continued monitoring will help constrain magma and gas recharge, reservoir pressure, conduit connectivity, permeability, and volatile segregation and outgassing. This research underscores Kīlauea's value as a globally accessible natural laboratory for developing new techniques in volcano monitoring and eruption forecasting.