Volcanoes are currently monitored by a wide range of sensors on land or orbiting around the Earth. Volcanic gas monitoring is fundamental as it carries information on volcano degassing that can fuel eruptions. Some gas species, such as sulphur dioxide, are easily measured, but others are much more challenging to track.
By deploying more than 70 passive dosimeters at Mount Etna in Italy, one of the best monitored volcanoes worldwide, Terray et al.  document the first radon measurements in volcanic plumes. The spatial variations reveal some hotspots and are closely related to the main degassing pathways. The study also highlights that radon could be a non-negligible source of long-term radiation exposure to people who spend time around volcanic craters. Their 6-month deployment also reveals temporal variation of radon activity bearing promising results for future volcano monitoring efforts including in harsh environments.
Citation: Terray, L., Gauthier, P.‐J., Breton, V., Giammanco, S., Sigmarsson, O., Salerno, G., et al. . Radon activity in volcanic gases of Mt. Etna by passive dosimetry. Journal of Geophysical Research: Solid Earth, 125, e2019JB019149. https://doi.org/10.1029/2019JB019149
—Corentin Caudron, Associate Editor, JGR: Solid Earth