Estimations of eruption column height during Etna eruptions: a new database based on visible calibrated cameras

During the last decades, explosive activity of Mt. Etna (Italy) has increased. Those events produced powerful lava fountains which form high eruption columns rising up to 15 km above sea level and low intensity and long-lasting explosive activity producing weak plumes of few kilometres above the summit craters. During Etna explosive activity, the estimation of the eruption column height is very important for several reasons. This value is inserted in the Volcano Observatory Notices for Aviation (VONA) messages sent by the Istituto Nazionale di Geosifica e Vulcanologia, Osservatorio Etneo (INGV-OE) as monitoring and surveillance duties. The column height is also one of the main eruption source parameters needed to run volcanic tephra dispersal models. Luckily, the column height is one of the easiest features that can be detected in real time using different ground-based instruments (e.g. cameras, radar and lidar) and satellite spectrometers. In this work, we analyse images of two visible calibrated cameras of the permanent video-surveillance system of INGV-OE. They are installed on the south and west sectors of Etna volcano flanks and the column height is estimated also considering the prevailing wind direction above the Etna summit craters. Data cover the period between 2014 and 2022 and were selected on the base of the VONA messages sent by INGV-OE. For the first time, this new database includes the time-variation of the column height for each explosive event. Our analysis, now free available, could be used in future to: i) analyse each explosive activity at Etna volcano; ii) validate new techniques aimed at estimating the eruptive column heights; iii) improve the modelling of eruption column; iv) estimate the mass eruption rate, another key parameter characterizing the explosive activity.