【摘要】 综合考虑震中地区地质构造背景、震源机制解结果、余震分布以及我国西部地区地震动参数衰减特征,运用考虑场地效应的震动图快速生成方法,将收集到的62组强震台站的峰值加速度作为插值使用,估计了2014年8月3日云南鲁甸MS6.5地震峰值加速度震动图.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得到的估计值之间的系统偏差,校正了缺少台站地区借助经验性衰减关系得到的估计值,获得了校正后的峰值加速度分布图.结果显示,鲁甸MS6.5地震的地震动峰值加速度随距离的衰减速度比前人对我国西部衰减统计的结果更快,对数偏差校正的结果更符合本次地震的衰减规律.校正后的峰值加速度大于40cm/s2的区域面积近8 000km2,比未经校正的峰值加速度大于40cm/s2的面积减小了40%左右.更多还原

【Abstract】 Considering the geological structure background,focal mechanism solutions,aftershock distribution and attenuation characteristics of the ground motion in western China,ShakeMap of peak ground acceleration(PGA)for the Ludian,Yunnan,MS6.5earthquake on 3August 2014 was acquired,in which the method of rapid generation ShakeMaps considering site effects was used,and the PGAs of 62 strong motion stations for this earthquake were used as interpolation.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 attenuation of ground motion with distance for the Ludian MS6.5earthquake was faster than that from previous studies on western China.The result by correction for bias in logarithmic regression was more consistent with attenuation law for this earthquake.The area with corrected PGA greater than 40cm/s2 was nearly 8 000km2,which was reduced by about 40% compared with that of uncorrected.更多还原