In tectonic and volcanic regions earthquake swarms and seismic sequences are frequently characterized by complex temporal evolution, and a delayed occurrence of the largest magnitude earthquakes. The complex evolution of such seismic sequences is generally considered to derive from transient forcing where fluids play a major role causing slow-slip and creeping events, and – at volcanoes – stresses due to magma migration (i.e. dike intrusion and pressurization of the magma plumbing system). Yet, the mechanisms of fluid-rock interaction, leading to changes of the rheological properties of faults, and of the fracture mechanics, are still far beyond a full understanding. Therefore, it is fundamental to develop and implement innovative methodologies and technologies or to apply multi-disciplinary approaches for a multi-parametric crustal imaging aimed at tracking fluid movements and/or pore fluid-pressure diffusion within the seismogenic crust, and to integrate the results with the analysis of spatio-temporal and size characteristics of earthquake occurrence. The two approaches complement each other improving, on one hand, our understanding of crustal properties and, on the other hand, help constraining the degree of involvement of fluids by the analysis of the earthquake statistics.
This session aims at putting together studies of swarms and complex seismic sequences modulated by aseismic transient forcing as well as field studies, numerical modeling, theoretical and experimental investigation on the detection and tracking of crustal fluids in tectonic, volcanic and industrial contexts. Contributions from multi-disciplinary studies of fluid geochemistry, surface ground deformation and space-time variations of electrical and seismic crustal properties are also welcome, as well as laboratory and numerical modeling simulating the mechanical condition yielding to fluid-driven swarm-like and complex seismic sequences.