Spatiotemporal properties of sub-Rayleigh and supershear ruptures inferred from full-field dynamic imaging of laboratory experiments

Vito Rubino, Ares J. Rosakis, & Nadia Lapusta

In Preparation October 12, 2019, SCEC Contribution #9945

Many earthquakes propagate at sub-Rayleigh speeds. Earthquakes propagating at supershear speeds, though less common, are by far more destructive. Hence, it is important to quantify the motion characteristics associated with both types of earthquake ruptures. Here we report on the spatiotemporal properties of dynamic ruptures measured in our laboratory experiments using the dynamic digital image correlation (DIC) technique. Earthquakes are mimicked by the frictional rupture propagating along the interface of two Homalite plates. Digital images of the propagating ruptures are captured by an ultrahigh-speed camera and processed with DIC in order to produce sequences of evolving displacement and velocity maps. Our measurements reveal the full-field structure of the velocity components, bridge the gap between previous spatially sparse velocimeter measurements available only at 2-3 locations, and enable us to quantify the attenuation patterns away from the interface.

Citation
Rubino, V., Rosakis, A. J., & Lapusta, N. (2019). Spatiotemporal properties of sub-Rayleigh and supershear ruptures inferred from full-field dynamic imaging of laboratory experiments. Journal of Geophysics Research, (in preparation).

Related Projects & Working Groups
Evolution of frictional shear resistance in response to rapid variations of normal stress, Fault and Rock Mechanics (FARM)