  In this paper, the mechanism of fault pressurization in rapid slip events is
analyzed on the basis of a complete characterization of the
thermo-poro-mechanical behavior of a clayey gouge extracted at 760m depth in
Aigion fault in the active seismic zone of the Gulf of Corinth, Greece. It is
shown that the thermally collapsible character of this clayey gouge can be
responsible for a dramatic reduction of effective stress and a full
fluidization of the material. The thickness of the 'ultra localized' zone of
highly strained material is a key parameter that controls the competing
phenomena of pore pressure increase leading to fluidization of the fault gouge
and temperature increase leading to pore fluid vaporization.
