Fault zone structures of northern and southern portions of the main central fault generated by the 2008 Wenchuan earthquake using fault zone trapped waves   总被引：1，自引：0，他引：1  

Songlin Li  Xiaoling Lai Zhixiang Yao  Qing Yang Geophysical Prospecting Center  China Earthquake Administration  Zhengzhou  China Institute of Geophysics  Beijing  China 《地震学报(英文版)》2009,(4):417-424

The rupture process of the May 12,2008 MS8.0 Wenchuan earthquake was very complex. To study the rupture zones generated by this earthquake,four dense temporary seismic arrays across the two surface breaking traces of the main-shock were deployed in July and recorded a great amount of aftershocks. This paper focuses on the data interpretation of two arrays across the central main fault,the northern array line 1 and southern array line 3. The fault zone trapped waves recorded by the two arrays were used to st...  相似文献   

Effects of vegetation on flow conveyance and sediment transport capacity   总被引：3，自引：0，他引：3  

Weiming WU  Zhiguo HE Research Assoc. Prof.  National Center for Computational Hydroscience  Engineering  University of Mississippi  University  MS  USA  Postdoctoral Research Assoc.  USA.Present at 《国际泥沙研究》2009,24(3):247-259

In-stream and riparian vegetation may significantly affect flow and sediment transport in vegetated channels. A hydraulic model has been developed in this paper to compute the flow discharge in channels with rigid and flexible vegetation under emergent and submerged conditions. An empirical formula has also been presented to determine the bed-load discharge in vegetated channels. The model has been tested against experimental and field data available in the literature. The computed flow discharge and bed-load transport rate agree well with the measured data.  相似文献   

Characteristics of present-day active strain field of Chinese mainland     

郭良迁  李延兴  杨国华  胡新康 《地震学报(英文版)》2008,21(6):562-572

On the basis of the GPS data obtained from repeated measurements carried out in 2004 and 2007,the horizontal principal strain of the Chinese mainland is calculated,which shows that the direction of principal compressive strain axis of each subplate is basically consistent with the P-axis of focal mechanism solution and the principal compressive stress axis acquired by geological method.It indicates that the crustal tectonic stress field is relatively stable in regions in a long time.The principal compressive stress axes of Qinghai-Tibet and Xinjiang subplates in the western part of Chinese mainland direct to NS and NNE-SSW,which are controlled by the force from the col-lision of the Eurasia Plate and India Plate.The principal compressive strain axes of Heilongjiang and North China subplates in the eastern part direct to ENE-WSW,which shows that they are subject to the force from the collision and underthrust of the Eurasia Plate to the North America and Pacific plates.At the same time,they are also af-fected by the lateral force from Qinghai-Tibet and Xinjiang subplates.The principal compressive strain axis of South China plate is WNW-ESE,which reflects that it is affected by the force from the collision of Philippine Sea Plate and Eurasia Plate and it is also subject to the lateral force from Qinghai-Tibet subplate.It is apparent from the comparison between the principal compressive strain axes in the periods of 2004～2007 and 2001～2004 that the acting directions of principal compressive stress of subplates in both periods are basically consistent.However,there is certain difference between their directional concentrations of principal compressive stress axes.The sur-face strain rates of different tectonic units in both periods indicate that the events predominating by compressive variation decrease,while the events predominating by tensile change increase.  相似文献   

用GPS研究南天山（伽师）地区现今地壳变形   总被引：49，自引：5，他引：44       下载免费PDF全文

王琪  丁国瑜  乔学军  王晓强 《地震学报》2000,22(3):263-270

伽师地区现今地壳运动方式、变动幅度和形变应变特征对研究该地区孕震环境具有重要作用．利用1994和1998年两次GPS大地测量,我们监测到伽师地区相对于北天山哈萨克地块的地壳缩短速率大约为19mm/a,与20世纪以来地震学（地震矩张量）资料估计的速率（约13mm/a）相比,GPS测定的速率高约50％．大地测量与地震学对南天山（伽师）地区地壳运动速率的估值差异,既可能说明该地区20世纪以来存在大量无震、震间应变,也可能表示至今与地震活动有关的断层变动尚不足以消减整个天山地区的现今变形．无论何种可能,从应力应变积累的角度看,都意味着天山西段及帕米尔东北侧一带发生强震的可能性将长期存在．   相似文献   

对样品含水结构的电阻率CT研究   总被引：14，自引：1，他引：13       下载免费PDF全文

郝锦绮  冯锐  李晓芹  周建国  钱书清  高金田 《地震学报》2000,22(3):305-309

采用高密度的电极阵列,对具含水结构样品的视电阻率值进行了测定,并重建了二维电阻率的图象．所得一系列CT图象揭示了样品内部由于裂隙和流体造成的真电阻率分布及其变化．这一方法用于岩石电性模拟实验,使导致样品电性变化的裂隙充水过程得以清楚地揭示．   相似文献   

中国大陆科学钻探工程简介   总被引：1，自引：0，他引：1  

中国大陆科学钻探工程中心地学部  Geological Department  the Center of the Continent 《地质论评》2000,46(1):48

随着航天技术的发展开辟了人类通往宇宙星际的大门,一个与之相呼应的“入地“计划应运而生,这就是直接观测地球陆壳的“大陆科学钻探”。作为伸入地球内部的“望远镜”,大陆科学深钻是当代地球科学具有划时代意义的大科学工程,是解决当代人类面临的资源、灾害和环境等重大问题的重要途径之一。 由于大陆科学钻探对当代经济、社会发展和科学进步具有重大意义,自70年代以来,俄、德、法、日、美和英等国家实施了大陆钻探,取得令人瞩目的科学研究成果,并带动了钻探和相关科学技术的大发展。  相似文献   

东营凹陷第三系流体物理化学场及其演化特征   总被引：10，自引：0，他引：10  

曾溅辉 《地质论评》2000,46(2):212-219

东营凹陷第三系为最重要的油气层系旬流体物理化学场及其演化特征：①地温梯度较高（现今地温梯度为３．６℃／１００ｍ）,自凹陷形成以来,地温梯度和大地热流值变化不大;②地层流体压力为中等超压－强超压,在剖面上可划分为静水压力过渡压力带和地质压力带;③地层水主要表现为沉积埋藏水的特点,并经历了沉积作用埋藏与淋滤作用并存和埋藏封闭作用３个演化阶段;④存在着静水压力、过渡压力和地质压力３个流体动力系统,其中过  相似文献   

New material of Cordaites baodeensis Sun from Lower Permian Shanxi Formation of Baode,Shanxi     

YANG Tao  .Research Center of Paleontology & Stratigraphy  Jilin University  Changchun  China.College of Earth Sciences  Changchun  China 《东北亚地学研究》2010,(1)

Based on the anatomical study of leaf cuticles of Cordaites from the Lower Permian Shanxi Formation in Baode of Shanxi,the author analysed the epidermal characters of Cordaites in this area.On the base of the abundant compressions and laboratory studies,the author complemented some new data of the cuticular characters of the species Cordaites baodeensis Sun for its study of taxonomy.Meanwhile,the author newly discovered a number of sporopollen fossils associated with the mega-plants of Cordaitales,described...  相似文献   

地震矩张量元素M_(rr)的空间分布与中国大陆岩石层地块   总被引：5，自引：0，他引：5       下载免费PDF全文

吴忠良  黄静  张东宁  周公威  张国民 《地震地质》2003,25(1):33-38

用哈佛CMT目录和中国地震震源机制目录给出了地震矩张量元素Mrr的符号的空间分布。这种空间分布图像相当于Tanimoto等 ( 2 0 0 0 )的“地壳势能变化”的空间分布图像的一种简化形式 ,Mrr的符号代表了地震震源处的应力状态。之所以进行这种简化是因为在相当多的情况下 ,地震的震源或矩心深度难以测准 ,并且震源机制目录的完整性得不到保证。将Mrr的分布图像与中国大陆岩石层地块的分布图像进行对照 ,可以发现由Mrr标志的地块内部的应力状态具有相当的一致性。地块边缘处的应力状态与地块内部的应力状态不同 ,似乎表明地块本身具有一定的整体性 ,同时地块之间存在相对运动  相似文献   

中国地壳运动速度场--GAMIT和GISPY解算结果比对   总被引：17，自引：9，他引：8  

牛之俊  游新兆  王琪  王敏 《大地测量与地球动力学》2003,23(3):4-8

采用"中国地壳运动观测网络"区域网1999、2001年的观测资料,利用GAMIT和GIPSY解出了测站位移速度值,并对这两种解算结果进行了对比分析.在920个观测站中,位移速度差东西、南北分量的平均值分别为(0.25±0.08) mm/a与(1.33±0.07) mm/a,服从(0.2,2.3)、(1.3,2.2)正态分布,两者无大系统差异,但大约2/3的测站速度差幅度在2～6 mm/a之间.导致速度场差异的原因可能是实现统一参考框架的误差和观测时间间隔不长对季节性地壳变动的放大作用等.  相似文献