%A Ortensia Amoroso
%A Alessandra Ascione
%A Stefano Mazzoli
%A Jean Virieux
%A Aldo Zollo
%J Geophysical Research Letters
%T Seismic imaging of a fluid storage in the actively extending Apennine mountain belt, southern Italy
%X A picture of the upper crustal structure of the Irpinia active faults system in southern Italy was obtained by combining new geological evidences, lithological properties, and microseismicity distribution. P and S wave velocity models indicate high VP/VS and low VP × VS values, suggesting fluid accumulation within a ~15 km wide rock volume where intense microseismicity is located. The 1980 Irpinia, Ms 6.9, earthquake nucleated within the same fault-bounded volume. We suggest that concentration of background seismicity is mainly controlled by high pore fluid pressure. Its increase in fluid-filled cracks around major faults leads to earthquakes' nucleation. Seismic pumping along major faults carries fluids through the conduit system represented by the intensely fractured damage zone. Conversely, the cross-fault barrier behaviour of the low-permeability fault core leads to pore fluid pressures building up within the fault-bounded block, thus producing a positive feedback triggering earthquake nucleation within the volume, which behaves as an “earthquake reservoir.”
%N 11
%P 3802-3809
%V 41
%D 2014
%I American Geophysical Union
%R doi:10.1002/2014GL060070
%L epos1710