Some thoughts on seismotectonics of major earthquake occurrence zones in China

来源 :中国工程科学:英文版 | 被引量 : 0次 | 上传用户:zhenlijinping
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
A major earthquake occurrence zone means a place where M ≥6 events have occurred since the Holocene and similar shocks may happen again in the future. The dynamic context of the major earthquake occurrence zones in China is primarily associated with the NNE-directed push of the India plate, next with the westward subduction of the Pacific plate. The Chinese mainland is a grand mosaic structure of many crust blocks bounded by faults and sutures. When it is suffered from boundary stresses, deformation takes place along these faults or sutures while the block interiors remain relatively stable or intact. Since the Quaternary, for example, left slip on the Xianshuihe-Xiaojiang fault zone in southwestern China has produced a number of fault-depression basins in extensional areas during periods Q1 and Q2. In the Q3, the change of stress orientation and enhancement of tectonic movement made faults of varied trends link each other, and continued to be active till present day, producing active fanlt zones in this region. Usually major earthquakes occur at some special locations on these active fault zones. During these events, in the epicenter areas experience intensive deformation character- ized by large-amplitude rise and fall of neighboring sections, generation of horst-graben systems and dammed rivers. The studies on palaeoearthquakes suggest that major shocks of close magnitudes often repeated for several times at a same place. By comparison of the Chi-Chi, Taiwan event in 1999 and Yuza, Yunnan event in 1955, including contours of accelerations and intensities, destruction of buildings, and in contrast to the Xigeda formation in southwestern China, a sandwich model is established to account for the mechanism of deformation caused by major earthquakes. This model consists of three layers, i.e. the two walls of a fault and the ruptured zone intercalated between them. This ruptured zone is just the loci where stress is built up and released, and serves as a channel for seismic waves.
其他文献
中央电教馆馆长陈志龙同志在参加教育部的相关会议后,立即对抗击“非典”工作进行了多方面细致周到的部署.rn首先,立即向北京市教委提供了可供播放的教学资源目录,供其选用;
2004年平罗县种植水稻9.61万亩,其中采用旱育稀植技术栽培1.64万亩,占水稻播种面积的17%。2005年平罗县旱育秧666.8亩,插植4.0万亩,面积的扩大,将使农民人均收入增加,但目前
期刊
锆合金由于具有良好的核性能以及耐蚀性能,因而用于核工业。随着核反应堆向高燃耗的发展,对锆合金的耐蚀性能要求越来越高。提高耐蚀性能的方法之一是离子注入,离子注入能显著地
基于绩溪县供水现状,强调了供水水源地水位自动测报系统建设的必要性,并介绍系统建设方法与相关要求.总结了系统运行情况,结合2015年案例表述了自动测报在供水水源优化调度中
期刊
目的建立慢性栓塞性肺动脉高压大鼠模型,研究肺动脉结扎对大鼠肺动脉平滑肌电压依赖性钾通道蛋白Kv1.5和Kv2.1 mRNA表达的影响,探讨疾病发生发展的机制。方法将雄性SD大鼠运用左肺动脉结扎法建立慢性栓塞性肺动脉高压大鼠模型,随机分为正常对照2周组、左肺动脉结扎2周组、假手术2周组和正常对照5周组、左肺动脉结扎5周组、假手术5周组,每组5只。直接右心测压法测6组大鼠右心室收缩压及平均压;取心脏称
采用田间取样和室内分析化验相结合的方法 ,分析测定了设施蔬菜田、露地菜田、粮田土壤有机质、碱解氮、速效磷、速效钾、有效铁、有效锰、有效铜、有效锌等养分含量。分析结
目的探索载短发夹RNA (shRNA)质粒的阳离子高分子脂质体(CPL)的制备方法及其理化性质,确定二者耦合的最佳结合比,优化转染方案。方法构建CPL,并对其进行表征,通过噻唑兰比色法检测CPL对细胞增殖的影响。将CPL与载shRNA质粒耦合,分为空白对照组(不做任何干预)、Lipofectamine2000转染组及不同质量比(1∶0、1∶0.5、1∶1、1∶1.5、1∶2、1∶2.5、1∶3)的
目的探讨AKT基因修饰的羊水间充质干细胞(AF-MSC)移植于兔缺血再灌注损伤心肌模型后对其氧化应激状态的影响。方法将新西兰兔随机分成3组,A组:L-DMEM组、B组:AF- MSC(羊水间充质干细胞)组、C组:AKT-AFMSC(AKT-羊水间充质干细胞)组,建立兔心肌缺血再灌注损伤模型。再灌注开通前在梗死区及周边心肌外膜按分组类别直接注射:L-DMEM、AF-MSC和AKT- AFMSC。术后