Pore Pressure Pulse Drove the 2012 Emilia (Italy) Series of Earthquakes

Abstract

Pore Pressure Pulse Drove the 2012 Emilia (Italy)Series of EarthquakesGiuseppe Pezzo1, Pasquale De Gori1, Francesco Pio Lucente1, and Claudio Chiarabba11Istituto Nazionale di Geofisica e Vulcanologia, Rome, ItalyAbstractThe 2012 Emilia earthquakes sequence is thefirst debated case in Italy of destructive eventpossibly induced by anthropic activity. During this sequence, two main earthquakes occurred separated by9 days on contiguous thrust faults. Scientific commissions engaged by the Italian government reportedcomplementary scenarios on the potential trigger mechanism ascribable to exploitation of a nearby oilfield.In this study, we combine a refined geodetic source model constrained by precise aftershock locationsand an improved tomographic model of the area to define the geometrical relation between the activatedfaults and investigate possible triggering mechanisms. An aftershock decay rate that deviates from theclassical Omori-like pattern andVp/Vschanges along the fault system suggests that natural pore pressurepulse drove the space-time evolution of seismicity and the activation of the second main shock