[关键词]
[摘要]
在2010 年4 月14 日07 时49 分( 北京时间) 青海省玉树藏族自治州玉树县(33. 2°N,96. 6°E)7. 1 级地震发生后,综合考虑震中地区的地质构造背景、活动断裂分布、震源机制结果、震源破裂过程、我国西部的地震动参数经验衰减关系及局部场地效应的影响,用考虑场地效应的震动图快速生成方法,在震后约2 小时后得到玉树地震震中地区的震动图,并提供给相关部门使用。结果表明,此次地震的地震烈度特征预测如下:①烈度的展布方向NW - SE 向,与玉树断裂的走向一致;②极震区的烈度为Ⅸ度,面积约为300km2 ;③烈度Ⅸ度区主要位于震中东南方向沿断裂走向近40km 和西北方向沿断裂走向15km 之间的区域;④Ⅸ度区的西北端由于局部场地条件的影响,其烈度由基岩参考面的Ⅸ度区降为土层上的Ⅷ度区;⑤Ⅷ度区面积约为3000km2 ;⑥Ⅶ度区的面积约为8000km2 ;⑦Ⅵ度区面积约为24000km2。
[Key word]
[Abstract]
On the basis of the geological structure setting in epicenter area,active faults,focal mechanism,the rupture process,the Western experience attenuation of ground motion parameter relations,and local site effects, ShakeMap of the April 14,2010 Yushu earthquake with magnitude 7. 1,Qinghai Province was obtained by prompt generation method of ShakeMap with the site effect. In about 2 hours after the earthquake occurrance,we provide it to the relevant departments. The results of Yushu earthquake ShakeMap show that the seismic intensity characteristics of our prediction are as follows: ① intensity distribution is the NW-SE direction, consistent with the strike of Yushu fault; ② maximum intensity is Ⅸ with an intensity area about 300km2 ; ③ extent of intensity Ⅸ mainly located between about 40km northwest of epicenter along the fault and 15km southeast of epicenter along the fault; ④ because of local site conditions in the northwest of intensity Ⅸarea,the intensity is reduced from Ⅸ on the bedrock to Ⅷ on the soil; ⑤ the area of intensity Ⅷ is about 3000km2 ; ⑥ the area of intensity Ⅶ is about 8000km2 ; ⑦ the area of intensity Ⅵ is about 24000km2 .
[中图分类号]
[基金项目]
地震行业科研专项201108002、201108014; 中国地震局地球物理研究所基本科研业务专项资助