In this paper,we summarized the time-space-intensity characteristics of earthquakes in the world,Chinese Mainland and adjacent areas,Sichuan and adjacent areas in 2023.Specifically,we analyzed the global characteristics of MS≥6.0 events and the regional characteristics of MS≥5.0 events in Chinese Mainland and its neighboring regions.The seismicity pattern and the sustained aftershock activity of strong earthquakes in recent years have been tracked in Sichuan and neighboring areas.The results show 1)the global frequency of major and strong earthquakes is higher in the circum-Pacific seismic belt than in the Eurasian seismic belt.The seismic intensity of the Eurasian seismic belt is higher than that of the circum-Pacific seismic belt.The characteristics of the time series with MS≥7.0 earthquakes throughout the year(2023)show alternating strength and weakness;2)The earthquakes with MS≥5.0 in the Chinese Mainland show scattered activities in the first grade active tectonic blocks of the Xiyu,Qinghai Tibet,North China and South China.The earthquakes in the Xiyu block are concentrated in the southern Tianshan region;3)Earthquakes are weaker within the Qinghai Tibet block than that in the surrounding areas.The MS≥5.0 Earthquakes have occurred in the North China block,South China block and the edges.Seismicity in Chinese Mainland is still strong in the west and weak in the east.The seismic intensity in the western region in is lower than in 2023 that in 2022;4)The seismic intensity in the eastern region is higher in 2023 than in 2022.The seismic intensity in Taiwan and nearby sea is significantly lower in 2023 than in 2022.The frequency in Taiwan and offshore areas is markedly lower than the average of the 14 times/year since 1900.The intensity and frequency of the seismicity in the second grade active tectonic blocks of the Bayan Har and Sichuan-Yunnan,which controls strong earthquakes in Sichuan and neighboring areas are relatively weak;5)No prominent strong earthquakes occurred,only aftershocks and several earthquake swarms with ML4.4 appear in the western region of Sichuan in 2023.Earthquakes above ML4.0 are mainly concentrated in the southeastern Sichuan region of the South China block.19 out of the 34 earthquakes with ML≥4.0 within the provincial boundaries are distributed in the southeastern Sichuan region,accounting for 55.88%of the total for the year.
万方数据
维普
