Based on the analysis of various seismological indexes of the Menyuan MS6.9 earthquake on January 8, 2022, it was found that the load/unload response ratio (LURR) presented obvious anomalies before and after the earthquake, with a short-term abnormal trend. The anomaly characteristics of M≥6 earthquakes along the Lenglongling fault zone of Qilian Mountain structural belt in northeastern Qinghai-Tibet Plateau were analyzed by the analogical induction method. It was considered that the LURR usually fluctuated around 1, and gradually rose to the peak value two months before the strong earthquake. Then the LURR fell back to about 1, and after a period of lag time (usually 10 days, or even longer), the strong earthquake occurred, and the greater the magnitude, the longer the lag time. Strong aftershocks in the study area have similar characteristics. The characteristics of LURR can provide reference for earthquake prediction and post-earthquake trend judgment in areas around the epicenter and areas with similar structural belt.
许延军,张学辉,曹勇,蒲小武,周明辉,张佳佳,王燕萍.门源6.9级地震前地应变加卸载响应比异常分析[J].地震工程学报,2022,44(3):707-712. XU Yanjun, ZHANG Xuehui, CAO Yong, PU Xiaowu, ZHOU Minghui, ZHANG Jiajia, WANG Yanping. Load/unload response ratio anomalies of strain beforethe Menyuan MS6.9 earthquake[J]. China Earthquake Engineering Journal,2022,44(3):707-712.复制