Mapping and evaluating kinematics and the stress and strain field at active faults and fissures: a comparison between field and drone data at the NE rift, Mt Etna (Italy)

Abstract

Abstract. We collected drone data to quantify the kinematics at extensional fractures and normal faults, integrated this information with seismological data to reconstruct the stress field, and critically compared the results with previous fieldwork to assess the best practice. As a key site, we analyzed a sector of the northeast rift of Mt Etna, an area affected by continuous ground deformation linked to gravity sliding of the volcano's eastern flank and dike injections. The studied sector is characterized also by the existence of eruptive craters and fissures and lava flows. This work shows that this rift segment is affected by a series of NNE- to NE-striking, parallel extensional fractures characterized by an opening mode along an average N105.7∘ vector. The stress field is characterized by a σHmin trending northwest–southeast. Normal faults strike parallel to the extensional fractures. The extensional strain obtained by cumulating the net offset at extensional fractures with the fault heave gives a stretching ratio of 1.003 in the northeastern part of the study area and 1.005 in the southwestern part. Given a maximum age of 1614 CE for the offset lavas, we obtained an extension rate of 1.9 cm yr−1 for the last 406 years. This value is consistent with the slip along the Pernicana Fault system, confirming that the NE rift structures accommodate the sliding of the eastern flank of the volcano.

Towards Enhanced Understanding and Experience of Landforms, Geohazards, and Geoheritage through Virtual Reality Technologies in Education: Lessons from the GeoVT Project

“…In fact, modelling of a virtual scene is a very important component of the application of VR technology in geohazard studies and education [67]. Thus, digital 3D models were used to reproduce landscapes vulnerable to geohazards such as landsliding [70][71][72], volcanic eruptions [7,8], and flooding [73,74], but also subject to technological hazards such as dam failing [75].…”

“…Virtual reality, capable of simulating real landscapes, has proven particularly useful in geomorphology and related subjects, in research, teaching, and professional training. Obvious targets are inaccessible or poorly accessible localities, such as submarine landscapes [3,4], planetary surfaces [5], high mountain environments [6], and places too dangerous to visit in person, such as sites of active volcanism [7,8]. The use of VR in education shows considerable growth in general [9,10], and teaching geomorphology is not an exception.…”

A New Way to Explore Volcanic Areas: QR-Code-Based Virtual Geotrail at Mt. Etna Volcano, Italy

“…It is easily transportable in the field, and it can be flown at a very low altitude, thus allowing for a greater resolution and proving to be very helpful for capturing videos and pictures for building 3D models [36]. Moreover, it is also suitable for automatized flight missions, a feature that is especially useful for modeling wide areas (further details in Tibaldi et al [37]).…”

Virtual Geosite Communication through a WebGIS Platform: A Case Study from Santorini Island (Greece)

“…They can be easily carried in the field and collect pictures flying at a very low height, resulting in a greater ground resolution and proving very useful for VGs reconstruction [71]. In addition, UAV2 is also designed for automatized flight missions, a peculiarity that is especially suitable for modeling large areas (further details in [72]). Generally speaking, the pictures collected using drones or cameras need to have a high overlap ratio, usually greater than 75-80% with the following pictures and must be orthogonally oriented to the target [73].…”

“…An additional marker needs to be positioned in the centre; this procedure aimed at reducing any "doming" effects resulting from photogrammetry modeling. More details regarding our workflow are in [54,68,72]. As explained in the previous section, some models are derived from previous work.…”