Laboratory Simulation of Volcano Seismicity

Abstract

Physical processes generating seismicity within volcanic edifices are highly complex and remain not fully understood. We report results from a laboratory experiment in which basalt from Mount Etna volcano (Italy) was deformed and fractured. The experiment was monitored using an array of transducers around the sample to permit full-waveform capture, location and analysis of microseismic events. Rapid, post-failure decompression of the water-filled pore volume and damage zone triggered many low frequency events, analogous to volcanic long period seismicity. The low-frequencies were associated with pore fluid decompression and were located in the damage zone in the fractured sample; these events exhibited a weak component of shear (double-couple) slip, consistent with fluid-driven events occurring beneath active volcanoes.