Earthquake delay and rupture velocity in near-field dynamic triggering dictated by stress-controlled nucleation

Earthquake dynamic triggering by seismic waves is widely observed while its nucleation mechanism remains unclear. We use tightly constrained earthquake laboratory experiments involving high-speed and full-field measurements to provide the first conclusive experimental evidence of dynamically triggered earthquakes by stress-waves. We define the overriding control of stress state on both the earthquake nucleation process and the transition from typical (subRayleigh) rupture to rapid and enigmatic supershear rupture which is more damaging in generating strong ground shaking. These results help explain key characteristics of near-field dynamic triggering featuring relatively short time delays and provide a simple theoretical framework for dynamic triggering at greater distances. Such understanding is thus beneficial to the short-term warning/prediction of earthquakes and earthquake hazard mitigation.<br>The original data for eight tests are provided in test#number.rar, respectively. The data of Fig.2a, Fig.2b, Fig.3, Fig.4, Fig.S1, Fig.S2 and Fig.S3 are given in the corresponding excel files, respectively.<br><br><br>