Fine ash from Mount Etna rose 74 centimetres (29 inches) inside a laboratory chamber without a gust of wind, setting a new high for experiments measuring how electrical charge moves volcanic particles. The study, published on Friday in the Italian Journal of Volcanic Processes, says the rise was more than six times the previous laboratory benchmark of 11 centimetres (4.3 inches).
The result does not mean ash routinely shoots that high above the volcano. But the authors say it shows that electrical forces, often treated as a minor effect in eruption forecasts, can lift particles on their own and may help keep dangerous ash suspended after an eruption’s initial blast.
A chamber built for ash
Researchers at the Sicilian Institute for Volcanic Physics tested ash collected from Etna in a clear vertical chamber in Catania. They tumbled the grains to build up static charge, then filmed their movement with high-speed cameras. In 18 trials, particles climbed more than 50 centimetres (20 inches) seven times; the highest rise came in a 90-second run.
Lead author Adam P. Tekin said the team had expected charged grains to hop, not form a sustained upward plume. “At 74 centimetres, we stopped the footage and checked the scale twice,” he said. The largest particles fell back quickly, while some of the finest dust continued to circulate near the chamber’s top.
The study also compared its laboratory results with electrical measurements taken during three Etna ash episodes between 2022 and 2025. The authors report that charge readings rose sharply as ash particles collided in the plume. They say that pattern is consistent with the chamber experiment, but does not prove the same lift occurred at the same height outdoors.
Forecasts face a blind spot
Janina S. Agatas, a volcanologist at the Alpine Centre for Earth Hazards in Bolzano who was not involved in the work, said the experiment was convincing but its scale matters. “A chamber is not an eruption cloud. The next question is whether these forces can move enough ash, for long enough, to change what falls on the ground,” she said.
Current ash forecasts rely heavily on wind speed, particle size and eruption height. The researchers argue that charge should be measured too, especially during dry, ash-rich eruptions. They propose adding compact electrical sensors to two existing monitoring stations on Etna before the volcano’s next active season.
The team plans to test ash under changing humidity and stronger simulated winds, conditions that could weaken or redirect the electrical lift. Tekin said the new figure should not be used to redraw hazard maps yet, but that ignoring charge could leave forecasts short by several kilometres when fine ash remains aloft. Etna, Europe’s most active volcano, rises above Sicily’s densely populated eastern coast.
