Imaging Stress and Faulting Complexity Through Earthquake Waveform Similarity

Abstract

While the rupture processes of nearby earthquakes are often highly similar, characterizing the differences can provide insight into the complexity of the stress field and fault network in which the earthquakes occur. Here we perform a comprehensive analysis of earthquake waveform similarity to characterize rupture processes in the vicinity of Ridgecrest, California. We quantify how similar each earthquake is to neighboring events through cross correlation of full waveforms. The July 2019 Ridgecrest mainshocks impose a step reduction in earthquake similarity, which suggests variability in the residual stress field and activated fault structures on length scales of hundreds of meters or less. Among these aftershocks, we observe coherent spatial variations of earthquake similarity along the mainshock rupture trace, and document antisimilar aftershock pairs with waveforms that are nearly identical but with reversed polarity. These observations provide new, high‐resolution constraints on stress transfer and faulting complexity throughout the Ridgecrest earthquake sequence.

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