2024-02-19T00:00:00 ingv Istituto Nazionale di Geofisica e Vulcanologia FORNACIAI Alessandro [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] FORNACIAI Alessandro [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] https://orcid.org/0000-0003-4829-4928#412 Istituto Nazionale di Geofisica e Vulcanologia (INGV) N/A FAVALLI Massimiliano [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] https://orcid.org/0000-0002-7338-6069#383 FAVALLI Massimiliano [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] MULTIPOLYGON (((15.1921 38.7951, 15.1995 38.7951, 15.1995 38.7914, 15.1921 38.7914, 15.1921 38.7951))) {"type": "MultiPolygon","coordinates": [[[ [15.1921,38.7951], [15.1995,38.7951], [15.1995,38.7914], [15.1921,38.7914], [15.1921,38.7951] ]]]} Ciencia y tecnología Science and technology Wissenschaft und Technologie Scienza e tecnologia Science et technologie Istituto Nazionale di Geofisica e Vulcanologia (INGV) ingv http://www.ingv.it/it/ 2024-01-01T00:00:00 INGV INGV ingv_967 vulcani 10.13127/stromboli/2022-uas-survey NANNIPIERI Luca [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] NANNIPIERI Luca [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] https://orcid.org/0000-0002-7529-1020#393 BEVILACQUA Andrea [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] BEVILACQUA Andrea [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy] https://orcid.org/0000-0002-0724-2593#408 UAS-based mapping of the July 3rd 2019 clast density distribution on the W flank of Stromboli with uncertainty quantification Stromboli is a volcanic island in a persistent state of activity, located off the northern coast of Sicily. The paroxysms have been the most powerful explosive phenomena at Stromboli in the last 150 years. These explosions can produce ballistic projectiles that can heavily affect trails and observation sites as well as hit inhabited areas at lower elevations, down to the coast. On July 3rd 2019 a paroxysm significantly affected a great portion of the island with ballistic projectiles. In particular, many decimeter and meter-sized spatter bombs hit the W flank of Stromboli, and ignited multiple fires. In May 2022, we conducted an Unmanned Aerial System photogrammetric campaign over a sector of the W flank of Stromboli that was heavily affected by the paroxysm. The greatest clasts were still preserved after three years, not disturbed by significant mass wasting phenomena or human interference, and they were not yet hidden by the post-fire regrowth of the brush vegetation. In this study we constrained the main sources of uncertainty affecting the bombs distribution on the ground, by characterizing a percentage of uncertain clasts, by testing various density estimators, and by modeling an areal buffer around the mapped clasts. We produced a 0.18 km2 wide 1.6 cm resolution orthomosaic, a 10 cm resolution Digital Surface Model, vectorial data of the detected clasts. Spatial distribution of the ground cover and associated uncertainty were analyzed as a function of the distance and of the angular direction from the source.