MS 5.5 and MS 5.0 earthquakes occurred in Subei County,Gansu Province on October 24 and December 1,2023 respectively which were located in the western section of the Qilian Mountain seismic belt. Pattern informatics (PI) and load/unload response ratio (LURR) are used to detect the stress state during interseismic and post-earthquake activity of the two earthquakeswhich provides reference for analyzing the future seismic activities of Qilian Mountain area. The results show that,① The PI hot spot calculation results indicate that there is a significant background stress anomaly in Subei area,and its amplitude indicates that there is a possibility of a magnitude 6 earthquake in this area in the next year. ②The temporal and spatial evolution characteristics of LURR indicate that the stress state in the source region has significantly changed in 2023,the LURR time series curve has shown obvious abnormal upward changes since the beginning of 2023,and the spatial distribution of anomalies continues to migrate to the source region,which indicate the possibility of strong earthquakes in the short and medium term. ③The temporal and spatial characteristics of LURR anomalies in the seismic area still show a continuous development state after the occurrence of the two earthquakes,and have not returned to normal levels. Therefore,it is still necessary to pay attention to the possibility of a magnitude 6 earthquake in the western part of the Qilian Mountain seismic belt in 2024.
关键词
肃北MS/5.5地震/肃北MS/5.0地震/图像信息法/加卸载响应比/祁连山地震带
Key words
Subei MS 5.5 earthquake/Subei MS 5.0 earthquake/Pattern informatics/load/unload response ratio/Qilian Mountain seismic belt
维普
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