Prof. Romain Jolivet of ENS Paris will present a special talk for the MIT EAPS Geophysics Group. "Creeping faults as the signature of fluid upwelling across the brittle crust."

"Currently identified conditions for slow, aseismic slip along active faults include specific rheological properties of the fault zone, geometrical complexities and fluids. Identifying the influence of these elements on the spatial and temporal behavior of aseismic is key toward a better understanding of why some faults creep while others generate large devastating earthquakes. We focus here on the central section of the North Anatolian fault zone, where aseismic slip has been identified in the 1970’s. We use various types of geodetic data to image the distribution of slip at depth along the fault as well as slow slip events. We discuss the corresponding rheological implications and propose that fluids may play a role, explaining both the spatial and the temporal distribution of slow slip along the NAF central section. We expand the discussion to other fault zones, including the San Andreas Fault and infer that creeping segments might be the signature of fluid upwelling through the brittle crust."