Field observations of maturely slipped faults show a generally broad zone of damage by cracking and granulation. Nevertheless, large shear deformation, and therefore heat generation, in individual earthquakes takes place with extreme localization to a zone <1–5 mm wide within a finely granulated fault core. Relevant fault weakening processes during large crustal events are therefore likely to b...

We treat a fault as an array of asperities with a prescribed statistical distribution of strengths. When an asperity fails, the stress on the failed asperity is transferred to one or more adjacent asperities. For a linear array the stress is transferred to a single adjacent asperity and for a two-dimensional array to three adjacent asperities. Using a renormalization group (RG) method, we inves...

[1] We report on laboratory experiments in which stick-slipping shear surfaces are subject to transient stressing to simulate earthquake triggering by seismic waves. Granular layers and bare granite surfaces were sheared in a servo-controlled deformation apparatus in double-direct shear. The seismic waves from an earthquake and tectonic load were simulated by superimposing a loading rate sinuso...

[1] Comparison of an electrical resistivity section derived from magnetotelluric (MT) data to a geologic section extending eastward from the Sierra Nevada near latitude 36 200N shows that the crust is dominated by steeply dipping conductive features that correlate with active strike-slip faults. While there is a subhorizontal conductor at a depth 20 km beneath some of the profile, it is broken ...

*Correspondence: [email protected] 1EOST, Université de Strasbourg/CNRS, 5 rue René Descartes, 67000 Strasbourg, France Full list of author information is available at the end of the article Abstract Background: Observations in enhanced geothermal system (EGS) reservoirs of induced seismicity and slow aseismic slip ruptures on related faults suggest a close link between the two phenom...