利用强震记录校正的芦山7.0级地震峰值加速度震动图

SHAKEMAP OF PEAK GROUND ACCELERATION WITH BIAS CORRECTION FOR THE LUSHAN,SICHUAN EARTHQUAKE ON APRIL 20,2013

运用考虑场地效应的震动图快速生成方法,综合考虑震中地区地质构造背景、震源机制解结果及中国西部地区地震动参数衰减特征,估计了2013年4月20日芦山7.0级地震加速度分布图。利用地震后获得的强震记录计算了强震台站观测值与借助经验性衰减关系估计值之间的系统偏差,进一步修正了峰值加速度分布图。结果显示,由于芦山地震属于高角度逆冲型地震,加大了震区的震动程度,特别是震中附近30km范围内震动程度比校正前的结果更高。

After the Lushan, Sichuan earthquake on April 20,2013, based on the tectonic background, the distribution of active faults in the epicenter area, the focal mechanism solutions of this earthquake, the ground motion attenuation in western China and local site effect, ShakeMap of PGA was acquired. Then, distribution of PGA was amended by using PGA observations to correct system bias of theoretical estimates in the area without PGA observations. The results show that the vibration in epicenter area increased because the Lushan earthquake is a high-angle thrust earthquake. Especially,the vibration within 30km of the epicenter is more intense than the uncorrected results.