WHAT ARE THE CONNECTIONS BETWEEN IDEALIZED MODELS OF DYNAMIC WEAKENING AND FAULT-ZONE STRUCTURES?

Our understanding of fault-zone processes has benefitted from an impressive breadth of complementary research techniques that have engaged the efforts of field geologists, experimentalists, seismologists, and modelers. A challenge in synthesizing the results of these studies involves reconciling the motivations, viewpoints, and terminology of specialists in these different fields. For example, in an effort to elucidate the central operating mechanisms, mathematical models are commonly constructed that blend differing degrees of physical insight with extremely idealized treatments that neglect most of the complexities in natural geologic settings. In some cases, omissions are intentional, in others they are the product of ignorance. I discuss how recent models of the thermal pressurization of fault gouge and flash weakening along asperity contacts could be improved with better knowledge of fault-zone parameters, and what evidence for these dynamic weakening processes might be sought in the field.