%A Francesco Mulargia
%A Andrea Bizzarri
%J Scientific Reports
%T Anthropogenic Triggering of Large Earthquakes
%X The physical mechanism of the anthropogenic triggering of large earthquakes on active faults is studied on
the basis of experimental phenomenology, i.e., that earthquakes occur on active tectonic faults, that crustal
stress values are those measured in situ and, on active faults, comply to the values of the stress drop measured
for real earthquakes, that the static friction coefficients are those inferred on faults, and that the effective
triggering stresses are those inferred for real earthquakes. Deriving the conditions for earthquake nucleation
as a time-dependent solution of the Tresca-Von Mises criterion applied in the framework of poroelasticity
yields that active faults can be triggered by fluid overpressures , 0.1 MPa. Comparing this with the
deviatoric stresses at the depth of crustal hypocenters, which are of the order of 1–10 MPa, we find that
injecting in the subsoil fluids at the pressures typical of oil and gas production and storage may trigger
destructive earthquakes on active faults at a few tens of kilometers. Fluid pressure propagates as slow stress
waves along geometric paths operating in a drained condition and can advance the natural occurrence of
earthquakes by a substantial amount of time. Furthermore, it is illusory to control earthquake triggering by
close monitoring of minor ‘‘foreshocks’’, since the induction may occur with a delay up to several years.
%N 6100
%P 1-6
%V 4
%D 2014
%I Nature Publishing Group
%R doi:10.1038/srep06100
%L epos155