InteGrated Laboratories to investigate the mechanics of ASeismic vs. Seismic faulting

GLASS

Principal Investigator Prof. Cristiano Collettini Earthquakes are potentially catastrophic phenomena that have a huge impact on the environment and society. Understanding the physical processes responsible for earthquakes and faulting requires high quality data and direct observations of the underlying phenomena. However, no direct measurements can be made at depth where earthquakes initiate and propagate. Our knowledge of the mechanical properties of fault zones relies on Earth surface observations and experiments conducted in rock deformation laboratories. Despite recent progress, we have much to learn about the mechanics of earthquakes and the complex and inherently scale-dependent processes that govern earthquake faulting. Numerous fundamental questions concerning the mechanical behaviour of faults remain unanswered: What are the rheological properties of fault zone materials that govern seismic or aseismic slip behaviour? How do the frictional and rheological properties of fault zones vary in space and time? How do aseismic and seismic slip interact in time and space? Here, I propose a novel approach that will employ integrated studies of geological, seismological and laboratory data to open new horizons about our understanding of seismic and aseismic faulting. Central Italy is a unique test site that can serve as a natural laboratory for the integration of high resolution data gathered from different disciplines. I propose to develop my innovative and multidisciplinary research to unravel the physico-chemico processes responsible for faulting phenomena ranging from aseismic creep to seismic slip. The proposed research will allow to create unprecedented insight into the mechanics of earthquakes and to investigate deformation processes from the crustal to the nano-scale and from a time window ranging from the seismic cycle to entire geologic fault history.

An example of the road to integration of GLASS. High resolution geophysical data define the geometry and seismic behaviour of a low-angle normal fault (a). Long term deformation processes are studied on an exhumed analogue pertaining to the same fault system (b) up to the nano-scale (c). Fault rocks collected in the field are tested in rock deformation friction experiments (d). Friction experiments (d) are compared with mineralogy (c) and the mechanics of the active low-angle normal fault (a).