New insights into real‑time detection of tephra grainsize, settling velocity and sedimentation rate

The real-time quantification of particle size and sedimentation rate during volcanic explosive eruptions is crucial to constrain ash plume properties and forecast their atmospheric dispersal. In this work, we validate the use of an optical disdrometer (the Laser Precipitation Monitor) to measure ash fallout using the Vulcanian explosions at Sakurajima Volcano (Japan) as a case study. For the first time, disdrometer data are used to distinguish individual settling particles from most of the falling aggregates, strengthening the capacity of optical disdrometers to characterize volcanic particle fallout in real time.

Freret-Lorgeril et al. 2022 (

March 28, 2022