地震震源与灾害评估分析:中国四川2008年5月12日Ms 8.0汶川地震

地震震源与灾害评估分析：中国四川2008年5月12日Ms
8.0汶川地震
陈胜早
【期刊名称】《高校地质学报》
【年(卷),期】2008(14)3
【摘要】汶川5月12日8.0级地震在构造上起因于印度板块与欧亚板块以每年约5 cm的速度聚敛,并因此而引起青藏高原的地壳物质向四川盆地及中国东南大陆运移.主震震源及余震活动集中于以龙门山为中轴的一条长约350 km、宽约100 km 的地震活动带.震源深度一般分布丁地壳脆性-韧性转换边界以上约10～20 km区间的地壳震源层之中,属浅源构造地震.主要震源机制与龙门山构造运动方式密切相关,以其地壳厚度向西急剧加厚、重力梯度带、高波速比(Vp/Vs～2.2)等深部异常及逆冲断层兼具走滑性质的地质构造为特征.在震源辐射、路径传播和场地效应研究的基础上,分别计算并比较了岩石和土壤条件下的地震响应谱,特别强调了土壤条件下的场地放大效应;同时对与地震安全性有关的一些问题如地质灾害、地震频谱设计、地震早期预警系统及中、长期至短期地震预报等进行了探讨;特别提供了一个由加权平均计算、以岩石条件下震波衰减模式为基础的地震频谱设计参考实例.地震构造与动力学研究可融人工程地质与环境工程等学科发展.经历汶川地震考验的一些新近设计和建设的工程项目可为今后改进工程建筑规范与标准提供重要而有益的参考.地震预报是当今一大难题,但需探索研究,不可懈怠.地震减灾与预防足目前比较切合实际的安全举措.%The May 12, Ms 8.0 Wenchuan earthquake is tectonically due to the convergence of the India plate against the Eurasiaplate at a rate of～50 mm/yr, which resulted in the crustal
movement toward the eastern Sichuan Basin and the southeastern China continent from the uplifted Tibetan Plateau. The epicentral area is located in the active Longrnenshan centralized seismic zone along which the aftershocks are concentrated within a～350 km long and～100 km wide active belt of horizontal projection.Hypocentral depths range generally from～10 to～20 km within the crustal seismogenic zone above the brittle-ductile transition boundary, characterized typically by shallow tectonic earthquakes. Focal mechanism of the Wenchuan earthquake bears a close correlation with the Longmenshan tectonic movement indicated by the particular deep structural anomalies of the rapid crustal transition deepened westward, gravity gradient, high Vp/Vs, ratio of average 2.2, aod geological features of thrust faulting style with strike slip history. Response spectra for rock and soil sites are, respectively, estimated and compared for different tectonic regimes, based on the study of source, path and site effects, emphasizing soil site amplication effect. Also studied are safetyconcerned issues for prevention of future damaging earthquakes including geological hazards, seismic design, earthquake earlywarning systems (EEWS), and strategies of long term to short term earthquake forecasting. A sample of design spectra is presentedon weighted average rock-site attenuation models. Topic on seismotectonics and earthquake dynamics in the areas of high seismic risk could be well incorporated with engineering geology and environmental engineering. Study on performances of the newly designed and constructed engineering structures should provide most valuable input to improving seismic design
codes in China and throughout the world. It is a challenging task to predict earthquakes; however, effort should never be given up. Earthquake disaster reduction and prevention is a realistic measure for safeguard of future damaging earthquakes.
【总页数】10页(P377-386)
【作者】陈胜早
【作者单位】南京大学,地球科学与工程学院,南京,210093
【正文语种】中文
【中图分类】P315
【相关文献】
1.2008年5月12日四川汶川8.0级地震与部分余震的震源机制解 [J], 郭祥云;陈学忠;李艳娥
2.2008年5月12日汶川地震(Ms8.0)地表破裂带的分布特征 [J], 李海兵;王宗秀;付小方;侯立玮;司家亮;邱祝礼;李宁;吴富峣
3.2008年5月12日汶川Ms8.0地震动力学背景的数值模拟实验 [J], 廖力;张东宁;杨建思
4.2008年5月12日四川汶川8.0级地震前后震源区应力水平估计 [J], 陈学忠;李艳娥;郭祥云
5.中国四川2008年5月12日汶川地震的地质与地球物理背景 [J],
B.C.Burchfiel;E.Kirby;任俊杰;L.H.Royden;R.D.Vander
Hilst;B.H.Hager;Z.Chen;R.W.King;C.Li;J.Lü;H.Yao
因版权原因，仅展示原文概要，查看原文内容请购买。