Is a geometric-kinematic approach valid for estimating the expected seismicity rates in volcano-tectonic areas? Ideas and results from seismogenic sources at Mt. Etna (Italy)

Abstract: At Mt. Etna (Sicily, Italy), the Timpe fault system is a structurally homogeneous domain characterized by a high seismic potential; several considerations led us to assume that faults are, on average, constantly loaded in time, supporting the idea that the faults behaviour is controlled by tectonic processes more than magma-induced, transient, stresses. The seismicity rates that have been till now assigned to the fault sources are based on macroseismic and instrumental data; they can be considered complete respectively above the damage threshold during the last two centuries, and for about ten years above ML=2. We are now testing if these results are coherent with the seismicity rates that can be obtained using a geometric-kinematic approach, widely used if only geological and structural data are available. The characterization of a magnitude-size scaling relationship in volcanic environment is a key step for closing the loop, but the preliminary results are encouraging.