Spatiotemporal Properties of Sub‐Rayleigh and Supershear Ruptures Inferred From Full‐Field Dynamic Imaging of Laboratory Experiments. Issue 2 (3rd February 2020)

• Record Type: Journal Article
• Authors: Rubino, V.; Rosakis, A. J.; Lapusta, N.
• Is Part Of: Journal of geophysical research. Volume 125:Issue 2(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-02-03
• Subjects: supershear -- sub‐Rayleigh -- earthquake mechanics -- attenuation -- laboratory experiments -- digital image correlation; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1029/2019JB018922
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: 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 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 digital image correlation 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 two to three locations, and enable us to quantify the attenuation patterns away from the interface. Key Points: We produce evolving maps of displacements and particle velocities for sub‐Rayleigh/supershear laboratory ruptures The maps confirm the structure of the near‐tip fields previously available only from theoretical and numerical models The measurements enable us to quantify the attenuation characteristics of the off‐fault motion