Geochemical and radiometric profiles through an active fault in the Sila Massif (Calabria, Italy)

Soil Degassing From the Xianshuihe–Xiaojiang Fault System at the Eastern Boundary of the Chuan–Dian Rhombic Block, Southwest China

“…We used the normal probability method proposed by Sinclair (1991) to objectively identify the threshold, which distinguishes different populations (background, mixing, and anomalous) well (e.g. Sinclair, 1974Sinclair, , 1991Sciarra et al, 2015Sciarra et al, , 2017Sciarra et al, , 2018Sciarra et al, , 2020Zhou et al, 2015;Yuce et al, 2017). The background population is related to surface processes, such as soil respiration, air dilution, and biological gas origin.…”

“…The anomaly population is primarily related to internal processes, such as fault/magma degassing (e.g. Chiodini et al, 2004;Sciarra et al, 2015, Sciarra, 2018, Sciarra, 2020Di Martino et al, 2016;Yuce et al, 2017). The mixing population represents soil gas with mixing sources by external and internal processes (e.g.…”

“…Rn is inert and has low mobility in the geological environment (Tanner, 1964;Dubois et al, 1995). The uranium decay and the upward migration of Rn along the fault could represent the two sources of Rn in the fault zone (Toutain and Baubron, 1999;Sciarra et al, 2015;Sciarra et al, 2017;Sciarra et al, 2018;Sciarra et al, 2020). Previous studies indicate that the emanating power of the rock and soil, the permeability of the host rock, and the flow of the carrying gas are the primary factors that influence Rn activity in a diffusive system (e.g.…”

“…Previous studies and field observations have demonstrated that faults and/or fractures are highly permeable pathways for gas migration from gas sources, which retain the signatures of gas sources in the soil cover (e.g. Fu et al, 2005;Ciotoli et al, 2014Ciotoli et al, , 2016Sciarra et al, 2015Sciarra et al, , 2017Sciarra et al, , 2018Sciarra et al, , 2020Yuce et al, 2017;Xiang et al, 2020). Gas anomalies are well-correlated with earthquakes (e.g.…”

Fractal Dimension Analysis Applied to Soil CO2 Fluxes in Campotosto’s Seismic Area, Central Italy

“…In addition, changes in stress/strain associated with seismic activity may force the migration of crustal fluid, in particular along active faults, thereby altering the geochemical characteristics of the surface fault zone [16][17][18]. The movement of these gasses by diffusion and/or advection along active faults will create flow anomalies, with concentrations substantially higher than the background levels; such anomalies may provide accurate information about the position and morphology of the shallow fracturing zone, as well as the permeability within the fault zone [3,4,7,[19][20][21].…”