Seismicity patterns before the 2021 Fin (Iran) doublet earthquakes using the region-time-length and time-to-failure methods  

作　　者：Salma Ommi Vladimir Borisovich Smirnov 

机构地区：[1]Department of Environmental Planning and Design,Environmental Science Research Institute,Shahid Beheshti University,Tehran,Iran [2]Department Physic of The Earth,Moscow State University,Moscow,Russia [3]Schmidt Institute of Physics of the Earth,Russian Academy of Sciences,Moscow,Russia

出　　处：《Earthquake Science》2024年第4期324-336,共13页地震学报（英文版）

摘　　要：Knowledge regarding earthquake hazards and seismicity is crucial for crisis management, and the occurrence of foreshocks, seismic activity patterns, and spatiotemporal variations in seismic activity have been studied. Furthermore, the estimation of the region-time-length (RTL) parameter has been proposed to detect seismic quiescence before the occurrence of a large earthquake. In addition, the time-to-failure method has been used to estimate the time occurrence of large earthquakes. Hence, in this study, to gain deeper insight into seismic activity in the southern Zagros region, we utilized the RTL algorithm to identify the quiescence and activation phases leading to the Fin doublet earthquakes. Temporal variations in the RTL parameter showed two significant anomalies. One corresponded to the occurrence time of the first earthquake (2017-12-12);the other anomaly was associated with the occurrence time of the second event (2021-11-14). Based on a negative value of the RTL parameter observed in the vicinity of the Fin epicenters (2021), seismic quiescence (a decrease in seismicity compared to the preceding background rate) was identified. The spatial distribution of the RTL prognostic parameters confirms the appearance of seismic quiescence surrounding the epicenter of the Fin doublet earthquakes (2021). The time-to-failure method was designed using precursory events that describe the acceleration of the seismic energy release before the mainshock. Using the time-to-failure method for the earthquake catalog, it was possible to estimate both the magnitude and time of failure of the Fin doublet. Hence, the time-tofailure technique can be a useful supplementary method to the RTL algorithm for determining the characteristics of impending earthquakes.

关 键 词：earthquake catalog seismic quiescence region-time-length(RTL)algorithm time-to-failure method Fin doublet earthquakes. 

分 类 号：P315[天文地球—地震学]