What Rubber and Jello Can Teach Us About Earthquakes and Fractures
Will Steinhardt
UC Santa Cruz Seismo Lab
- Date & Time
- Location
- Online-only seminar via Microsoft Teams
- Host
- Tim Clements
- Summary
Many systems in geophysics, including faults, ice sheets, and hill slopes, are predominantly stable, but become unstable catastrophically, with severe societal consequences when they do. However, the behaviors of these systems are often difficult to predict because they involve extreme spatial and temporal scales, accumulating stresses over decades or centuries, but nucleating failure processes at the micron-scale in fractions of a second leading to kilometers of deformation. In this talk, I will discuss how I utilize applied physics techniques to build scaled-down experiments to explore these complex problems in systems where a wide range of system properties can be tuned to make otherwise impossible observations. I will present two examples: First, using a scaled, transparent laboratory fault where slip at the interface can be directly imaged, I will show that slow slip events in our system follow earthquake-like scaling, and demonstrate how finite fault effects alter stress drop. Second, I will discuss how material heterogeneity leads to brittle fracture roughness, and show that the resultant morphology of a crack is, surprisingly, not dependent upon the details of the medium, but is controlled entirely by a single parameter: the probability to perturb the fracture front above a critical size to produce a step-like instability.
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