Researchers from the US Geological Survey used a recent series of eruptions at Kilauea to test competing models of what drives lava fountains. The study, published in Science, marks some of the best documentation yet of these dramatic jets of molten rock, which can rise hundreds of meters into the air.
After a 900-meter-long fissure opened in 2024, Kilauea produced two fountaining episodes within a day, followed by 52 more as of last month. The most violent sent lava over 400 meters high. An array of seismic, infrasound, gas, and thermal sensors showed that consecutive eruptions occurred when summit tilt reached similar levels, enabling the USGS to issue alerts before fountains restarted.
The chemical data lean toward a steam-driven mechanism rather than one based on carbon dioxide foam, since CO2 levels stayed low throughout the cycle. Sulfur dioxide and magnesium oxide changes are consistent with a reservoir that is depleted by eruptions and refilled with hot magma. Still, the authors note that the exact trigger remains unclear, and the difficulty of monitoring near active fountains limits what can be captured.