ALBERT

Description: Timely estimations of volumes erupted during an eruption or a sequence of explosive events is of vital importance for investigating the eruptive activity and evaluating the associated hazard. A reliable method for estimating erupted volumes is based on the analysis of different digital surface models (DSMs) that nowadays can be obtained as often as required, and with sufficient accuracy, using stereo optical satellite imagery. At Etna, during 2011-2013, 44 lava fountains occurred emitting a total volume of over 100×10〈sup〉6〈/sup〉m〈sup〉3〈/sup〉, as well as in 2020-2022 with over 60 events. Even if lava fountains produce limited deformation, effects, their high temporal frequency can produce large cumulative volumes. While thermal satellite imagery can provide estimates of lava volume, the real time estimation of the total deposits is still an open challenge. High precision strain recorded by borehole dilatometer (precision of order of 10〈sup〉-10〈/sup〉) is able to detect the effects of the source that feeds the lava fountain. The recorded changes in real-time are proportional to the volume variation of the source that empties feeding the eruption, and are therefore proportional to the total erupted volume. Here we use the volumes derived from multiple DSMs comparison to calibrate the volumes obtained from strain changes. The validation is performed by using the plenty of high spatial resolution satellite images and strain records available at Etna during 2020-2022. We show how this new approach can provide robust information on the erupted volumes both over time and in real-time through the strain recorded by continuous monitoring.