Foreshock-Induced Slip Transients Determine Mainshock Nucleation Timing
A new study published in Nature reveals that foreshocks play a critical role in regulating the timing and characteristics of earthquake mainshocks. Through laboratory experiments and a rate-and-state-based Griffith-like rupture framework, researchers demonstrated that foreshocks induce slip transients that set a transient sliding velocity. This velocity directly predicts the duration and spatial length of the nucleation phase before dynamic rupture occurs. The findings indicate that larger foreshocks generate higher sliding velocities, leading to a rapid transition to dynamic rupture, while smaller foreshocks result in prolonged quasi-static growth or arrested ruptures. By extending this theoretical model to tectonic faults, the study suggests that natural earthquakes follow similar scaling laws. These insights allow for the constraint of realistic characteristic nucleation slip distances to between 0.3 and 3.0 mm, which is significantly smaller than previous estimates for dynamic rupture. This research challenges classical models that largely neglect impulsive precursory events, offering new understanding of earthquake initiation mechanisms and potentially improving the detectability of precursory signals in seismology.
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Foreshock-Induced Slip Transients Determine Mainshock Nucleation Timing
A new study published in Nature reveals that foreshocks play a critical role in regulating the timing and characteristics of earthquake mainshocks. Through laboratory experiments and a rate-and-state-based Griffith-like rupture framework, researchers demonstrated that foreshocks induce slip transients that set a transient sliding velocity. This velocity directly predicts the duration and spatial length of the nucleation phase before dynamic rupture occurs. The findings indicate that larger foreshocks generate higher sliding velocities, leading to a rapid transition to dynamic rupture, while smaller foreshocks result in prolonged quasi-static growth or arrested ruptures. By extending this theoretical model to tectonic faults, the study suggests that natural earthquakes follow similar scaling laws. These insights allow for the constraint of realistic characteristic nucleation slip distances to between 0.3 and 3.0 mm, which is significantly smaller than previous estimates for dynamic rupture. This research challenges classical models that largely neglect impulsive precursory events, offering new understanding of earthquake initiation mechanisms and potentially improving the detectability of precursory signals in seismology.
Nature