The dynamic summer of 2024 at Etna volcano documented by UAS: morphological changes and their gravimetric effects

During the summer of 2024, Mt. Etna was characterized by a sequence of six powerful paroxysmal events originating from the Voragine summit crater. This activity marked a significant departure from the preceding years, when paroxysms at the Southeast Crater prevailed. The high dynamicity of this period required continuous and precise monitoring, mapping, and quantification, which were achieved through frequent Unoccupied Aerial System surveys. Using the difference of digital elevation models, which compared the pre-eruptive surface of April 29, 2024, against the post-eruptive surface of September 12, we clearly demonstrated a pattern dominated by net accumulation over the Voragine, with the greatest vertical accretion reaching over 108 m. This substantial growth, attributable to repeated lava effusion and pyroclastic deposition, established Voragine as the new peak of Mt. Etna, reaching an elevation of 3403 m a.s.l. We then analyzed the effect of topography changes on gravimetric terrain corrections, which is important for computing the complete Bouguer anomaly, and the impact of changes in the nearest topography on the prediction of vertical gravity gradients. This interdisciplinary work provides a detailed quantification of the eruptive products from Mt. Etna's 2024 volcanic sequence and highlights the critical impact of the resulting morphological changes on high-precision gravimetric surveying, thus emphasizing the need for up-to-date digital terrain models.