2000年以来福建及邻区4级以上地震前小震调制比特征分析OA

Based on the unified earthquake catalog of the China Earthquake Networks Center,by adopting the time-space scanning method of earth tide modulation ratio,this study analyzed the temporal and spatial evolution characteristics of modulation ratio before MS≥4 earthquakes in Fujian and adjacent areas since 2000.The results show that high-value anomalies of the modulation ratio were observed before 7 out of the 11 earthquakes cases ana-lyzed.The identification of these anomalies is closely related to their duration and amplitude.Spatially,anomalies are mainly distributed within 100 km of the epicenters.Temporally,the anomalies appeared on average about one year before the mainshocks,and most earthquakes occurred within 9 months after the peak values of the anomalies began to decline.The solid earth tide modulation ratio method has a certain indicative significance for the prediction of MS≥4 in Fujian and adjacent regions.