Active tectonics and volcano-tectonic processes are related to earthquakes, fracturing, fault motion (such as creeping), volcanic eruptions, caldera or flank collapse and magmatic intrusions, such as dyking. Satellite data using optical or thermal sensors provide first order information about faulting and volcanic activity, however, there is a resolution gap below the meter-scale, critical to detect and analyse small structures over broad areas and to better assess how faults, magma intrusions and collapses nucleate and evolve. During large deformations (earthquakes, dyke intrusions, collapses), the near-field area where satellite radar signal (InSAR) becomes incoherent remains poorly studied. In addition, classical field surveys and data collection are, very often, not feasible due to difficult logistic condition, hazardous accesses and/or inaccessible areas. Therefore, there is a need to collect higher resolution data to better understand faulting and volcanic processes at scales from cm to several meters, that complement classical field studies and satellite data. The scientific community has adopted modern direct and indirect methods to develop in the last decade, like the Structure from Motion (SfM) techniques.
SfM techniques have been applied using imagery acquired from field and aerial survey, using cameras and mobile phones, Unmanned Aerial Vehicles (UAVs, i.e. drones), balloons, airplanes and helicopters. This technique produces digital surface models (DSM), ortho-mosaic imagery, dense point clouds and 3D models, creating a high-resolution environment reconstruction for a single outcrop or a wide area. The session will focus on the application of the SfM techniques for research in the field of structural geology, with particular regard to active tectonics and volcano-tectonic processes. The session covers, without being limited to, the following topics: i) case studies where the SfM has been employed; ii) SfM methods, 3D reconstruction and successive analysis; iii) innovative application for SfM for survey, such as ground deformation analysis; iv) integration and comparison of SfM-derived, field and satellite data; v) new tools and methods for data analysis on SfM-derived models; and vi) future works and applications of SfM techniques.