Earthquakes represent a fundamentally challenging scientific problem. In the last decade the new geophysical discoveries have greatly improved our knowledge on how faults accommodate slip and on their ability to produce earthquakes. Geophysical and geodetic observations, source modeling and experiments suggest that faults are heterogeneous in their physical properties and temporal behavior, leading to variations and complexities in slip styles, friction, earthquake recurrence intervals and involved physical processes.
The aim of this project is to study the effect of fault rock (in terms of its fabric) and strain localization in controlling traction evolution and slip velocity time histories during laboratory earthquakes. We will use a double-direct biaxial shear apparatus and different fault gouges, including heterogeneous minerals mixture as a proxy for real fault rocks, to study slip events at the laboratory scale.
Measuring fine details of fault slip velocity time history, volumetric deformation and friction during many seismic cycles, coupled with an analysis of the microstructures, we want to get inferences on the physical processes at play.
The slip velocity function contains the dynamic information needed to characterize the evolution of stress during breakdown process and it is usually imposed a-priori during earthquakes kinematic modeling on natural faults due to the limited resolution of recorded data. With our project we want to study the spontaneous slip velocity function recorded during laboratory events and to relate its temporal evolution with shear fabric. Moreover, with the use of different fault gauges we want to get inferences on how the energy is differently absorbed on the slipping surfaces with significant insights for understanding of earthquake process.
Finally, the multidisciplinary geophysical team recently assembled in Sapienza will be a perfect environment to train PhD and Post-docs researchers interested in earthquake mechanics.
