We obtained a catalog of early aftershocks of the 2013 Lushan earthquake by examining waveform from a nearby station MDS which is 30.2 km far away from the epicenter, and then we analyzed the relation between aftersho...We obtained a catalog of early aftershocks of the 2013 Lushan earthquake by examining waveform from a nearby station MDS which is 30.2 km far away from the epicenter, and then we analyzed the relation between aftershock rate and time. We used time-window ratio method to identify aftershocks from continuous waveform data and compare the result with the catalog provided by China Earthquake Networks Center （CENC）. As expected, a significant amount of earthquakes is missing in CENC catalog in the 24 h after the main shock. Moreover, we observed a steady seismicity rate of aftershocks nearly in the first 10,000 s before an obvious power-law decay of aftershock activity. We consider this distinct early stage which does not fit the Omori law with a constant p （p - 1） value as early aftershock deficiency （EAD）, as proposed by previous studies. Our study suggests that the main shock rupture process is different from aftershocks＇ processes, and EAD can vary in different cases as compared to earthquakes of strike-slip mechanism in California.展开更多
基金supported by the State Key Laboratory of Geodesy and Earth’s Dynamics,Institute of Geodesy and Geophysicsthe Chinese Academy of Sciences through grant number SKLGED2013-7-1-Z
文摘We obtained a catalog of early aftershocks of the 2013 Lushan earthquake by examining waveform from a nearby station MDS which is 30.2 km far away from the epicenter, and then we analyzed the relation between aftershock rate and time. We used time-window ratio method to identify aftershocks from continuous waveform data and compare the result with the catalog provided by China Earthquake Networks Center （CENC）. As expected, a significant amount of earthquakes is missing in CENC catalog in the 24 h after the main shock. Moreover, we observed a steady seismicity rate of aftershocks nearly in the first 10,000 s before an obvious power-law decay of aftershock activity. We consider this distinct early stage which does not fit the Omori law with a constant p （p - 1） value as early aftershock deficiency （EAD）, as proposed by previous studies. Our study suggests that the main shock rupture process is different from aftershocks＇ processes, and EAD can vary in different cases as compared to earthquakes of strike-slip mechanism in California.
