Current crustal movement in Chinese mainland

The quantification of tectonic deformation in the Eastern and Central Asia is of great significance for the study on global plate motion and lithospheric dynamics. In the past four years, the velocity field of horizontal crustal movement for the Chinese mainland has been established for the first time thanks to the intensified GPS measurements and its improved accuracy. The velocity field derived from GPS measurements delineates the patterns of tectonic deformation in the Chinese mainland in the unprecedented detail, and thus reveals the new features of the ongoing tectonic process resulted from the collision of Indian plate to Eurasian plate. Meanwhile, the surface offset induced by two strong earthquakes occurred in Chinese mainland was sampled precisely using InSAR technique.

Recent crustal horizontal movement in the Chinese mainland

According to the results of careful re-proeessing of data obtained from two GPS survey campaigns of crustal movement monitoring network in Chinese mainland carried out in 1994 and 1996, the crustal horizontal movement characteristics in Chinesc mainland are studied in the paper.In the analysis, a relatively consummate deformation model in which the deformation is described by the relative movement between the tectonic blocks with interior strain and the corresponding analysis method are used. The magnitude of movement along the boundary zones between the tectonic blocks is calculated. And the characters and intensities between the main boundny zones are compared.

Essential Features of Tectonic Movement Revealed by Crustal Vertical Deformations in the Mainland of China

Based on the precise reieveling data of more than 260,000 km carried out from 1950 to 1991 in the Chinese mainland,recent crustal vertical movement is studied.By means of some quantitative indices,such as the pattern of crustal vertical movement,the intensity of differential movement,the maximum gradient and its distribution,etc.,the properties of movements are analyzed on a large scale.The results suggest that all the properties have a profound tectonic background of their own and are closely related to the zoning and seismic activity of active subplates.The driving force for the movement comes mainly from the northward push of the India plate acting on the Eurasia plate.The effects of motions of the Pacific and Philippine Sea plates in the east are much less significant.

Boundary conditions of the dynamicnumerical model for the Chinese mainland lithosphere

The numerical dynamic model of Chinese mainland lithosphere's stress and strain field was constructed withelasto-viscous creep constitive relation. The most recent data of the stress field of Chinese mainland and thehorizontal movement velocity of the crust blocks were used as constraint conditions. The values of the boundalsforce were computed by trial-and-error method. The effect of the Qinghai-Xizang Plateau's excess potential energyto the movement of Chinese mainland was studied also in this model. The results of the numerical computing showthat, recent rapid raising of the Qinghai-Xizang Plateau and the generation of normal faults in the southem part ofthe plateau resulted from the convergence of Indian Plate to the Eurasian Plate, and also from the rapid convectivethinning of the lower lithosphere. Horizontal extension of the Qinghai-Xizang Plateau is the main dynamic factorto torm the present tectonic framework of the Chinese mainland. The compressive loads on the eastern boundaryof the model were mainly applied by the subduction of the Pacific Plate. The compression from the PhilippinePlate maybe slight.

Current crustal motion and deformation inthe Chinese mainland and its surroundingarea determined from GPS data

Based on the geodetic data taken from the National GPS Network established by China Climbing Program 'Investigation of Crust Motion and Geodynamics in Modern Time', we derived the movement velocities of the GPS sites.In terms of the power series expansion of a rotation function for horizontal velocities on a spherical surface proposed by Hames and Holt (1993), we computed the horizontal velocity and strain-rate field.We preliminarilystudied the appearances and characteristics of the present-day crustal movement and deformation in the Chinesemainland with the computed results. The researches demonstrated (1)The present-day crustal movement anddeformation in the Chinese mainland are being jointly controlled by indian, Pacific and Philippines Ocean Platesand Siberia-Mongolia block, and these three large plates and block form a situation of triparite confrontation, butIndian Plate seems to play a leading role;(2) The North-South Earthquake Zone plays an important adjustment rolein the present-day crustal movement and deformation process. displaying clear characteristics of demarcation lineof tectonics in large areas, (3)There seems to be another adjustment zone along the latitude line approximate N35,but its characteristics are less obvious than that of the former; (4) Dynamic actions of these three large plates andblock on the Chinese mainland are dynamic stable; appearing in stable push-press velocities. These results aregenerally accorded with the results determined from geology, geophysics, and seismology. By the contrast withseismicities. if appears preliminarily that there is some corresponding relation between intense shear st fain zoneand future strong seismicity area. but this problem needs further examination of earthquake examples.

Recent gravity changes in China Mainland

Based on results of the mobile gravity measurements of the Crustal Movement Observation Network of China and Digital Earthquake Observation Network of China, this paper shows the pattern of temporal gravity changes in China mainland on a time scale of 2 - 3 years since 1998, and gives an analysis of the patterns. The result shows that the temporal gravity changes basically reflect the current mass movement and occurrence of strong earthquakes.

The structure features of stick-slip mechanism of the strike-slip earthquake generating structure in the interior of the Chinese mainland

This is the third one of the paper series on the strike slip earthquake generating structure in the interior of the Chinese mainland. The features of the tectonic stress field of strike slip earthquake generating structure were discussed in the first paper (Huan et al ., 1994), and the features of the deformation field of strike slip earthquake were presented in the second paper (Hun et al ., 1994). In the first section of this paper, through the analysis of the strike slip earthquake generating structure of several dozen large earthquakes with magnitude greater than 6.0, it is concluded that almost all strike slip earthquake generating faults are characterized by the oblique arranged distribution, and the barrier structure mode about the adhesive slip movement of strike slip is put forward; then in the second section, its four types, due to the different fracture form of the barrier at the ends, are also discussed; finally in the third section, the fracture terminating scale of the barrier of strike slip earthquake generating fault is also discussed.

中国大陆地壳运动与汶川M_s8.0级地震孕育的关系

根据网络工程的GPS站点观测资料,计算相对中国大陆整体1999-2007年的趋势运动速率和2004-2007年的动态运动速率,用青藏亚板块和华南亚板块的参数计算龙门山断裂带的活动参量,研究了中国大陆运动场和其变化,分析了地壳运动场的特征与汶川M_s8级地震的孕育关系.结果揭示出:现今地壳的运动分区与地质新构造单元基本一致,显示现代地壳构造活动是新构造运动的继承和发展;中国大陆地壳运动的动力主要与印度板块、太平洋板块与欧亚板块的相互碰撞俯冲产生的作用力有关.汶川M_S8级地震的发生,主要是由于印度板块对青藏亚板块的向北推挤、产生侧向运动,致使龙门山断裂带遭受挤压产生能量积累所致.2004 -2007年的地壳动态运动,使龙门山断裂带走滑活动加强,从稳定的压应变积累状态转人了剪切作用下的易活动状态.

中国大陆现今垂直形变特征的初步探讨

利用GPS观测资料进行大范围的垂直形变特征研究是本文研究的重点。通过网络工程基准站和基本站的GPS观测资料 ,绘制了中国大陆的垂直速率等值线图像 ,并对中国大陆垂直运动特征进行了定性的分析 ,结果表明 :中国大陆垂直运动在 70 %以上的区域表现为沉降运动 ,在青藏高原和除北京外的整个华北块体及燕山块体的垂直运动表现为隆升的趋势。中国大陆西北和东南、西南和东北的整体垂直运动呈一种斜对称状态。对基于GPS观测所得的等值线图与基于水准观测所得的等值线图进行了比较 ,比较结果显示 ,除了华南块体外 。

中国大陆主要构造块体现今运动的基本特征

为了研究中国大陆现代地壳运动和地球动力学 ,在 90年代初布设了由 2 2个站组成的全国GPS监测网 ,测站均匀布设在中国大陆不同块体上 ,1992、1994和 1996年对该网进行了3次观测。本文主要评述了 3次观测的资料处理和精度 ,分析了 3次复测获得的中国大陆现今块体运动的基本特征。研究结果表明 ,GPS网 3次观测获得的资料精度均达到 10 - 8～ 10 - 9,能满足地壳运动监测的需要。利用 3次复测资料结果所建立的我国大陆块体运动模型 ,有效地检验了地质学和地球物理学的研究结果。在全球框架中 ,我国大陆整体存在着明显的向东运动 ,相对于西伯利亚的区域性运动特征是 :我国西部地区主要受印度板块向北的俯冲和推挤的影响 ,青藏高原在南北向压缩的同时 ,存在着明显的向东的侧向滑移 ,这对大陆逃逸模型是较为有利的支持 ;东部地区的块体运动 ,同时受到印度板块以及太平洋板块、菲律宾板块的联合作用 ,导致了东部地区的北东向及东向的运动 ,到达东南沿海地区 。

中国大陆现今地壳垂直运动概貌及其地球动力学的某些特征

本文根据均衡理论，编绘了我国大陆地区现今地壳垂直运动速率图（不包括台湾、海南等岛屿）。结果显示，我国大陆地区的运动特征为“南升北降”、“东弱西强”；且明显地受印度板块和太平洋板块所控制，以印度板块的作用为最强烈。

中国大陆部分地区的地壳垂直运动

利用 195 2～ 2 0 0 2年间我国大陆部分地区 (90 .5°～ 12 7.3°E ,2 1.5°～ 4 4°N)的精密水准测量结果研究了这些地区的现今地壳垂直运动及其发展演变特点。将 5 0年的地壳运动分成两个时间段 :第一时间段的中心时刻 (资料观测时间的平均值 )为 1972 .87;第二时间段的中心时刻为 1983.17。对于这两期资料都采用了伪逆基准下的线性动态运动模型 ,求得的运动速率都归算到北京水准原点 (假定北京原点的运动速率为零 )。

中国地壳运动观测网络的建设及应用

"中国地壳运动观测网络"是国家"九五"期间建设的重大科学工程,自1998年开始观测以来,获取了大量的地壳形变GPS观测资料和相对重力观测资料,为认知中国大陆地壳运动特征及其动力学机制提供了至关重要的基础资料和定量约束。"十一五"期间,国家将实施中国地壳运动观测网络的二期工程"中国大陆构造环境监测网络",对网络中观测站点的空间密度、观测方式和应用功能进行大幅度强化。本文扼要介绍了中国地壳运动观测网络一期工程的建设内容、运行现状和主要成果及二期工程的建设规划。中国地壳运动观测网络一、二期工程将为我国地震监测和地学研究提供一个具有国际先进水平的大地测量基础平台。

中国大陆现今地壳水平运动

在重新仔细处理了 1 994和 1 996年中国大陆地壳运动监测网两次 GPS测量资料的基础上 ,采用较为完善的块体相对运动和块体内变形叠加的变形模型和相应的分析方法 ,研究了中国大陆现今地壳运动的运动学特征 ,并定量计算和比较了主要活动构造块体边界带的活动性质和强度 ,得到了一些新的认识 .

中国大陆现今地壳运动研究

中亚、东亚地区的构造变形的定量化对全球板块运动和岩石圈动力学研究具有重要意义 .最近 4年 ,利用空间技术 ,一个全面反映中国大陆地壳水平运动的实测速度场已基本完成 .GPS结果十分清晰地刻画出中国大陆地区块体运动及内部变形特征 ,提供了认识印度 欧亚碰撞引起的活动构造的新视角 .本文回顾了 4年来中国学者在利用GPS研究现今地壳运动方面所取得的成就 ,以及在利用InSAR技术研究强震破裂方面的进展情况 .这些研究成果 。

中国近期垂直陆地运动的几个主要特征

本文利用我国三十多年来积累的近三十万公里精密水准复测资料，研究了我国近期垂直陆地运动的主要特征，即：（１）我国陆地构造性垂直运动的主要特征为＂南升北降＂、＂东弱西强＂；并且与地形地貌具有一定的相关性，表现为清晰的继承运动性质，从运动量值及等值线的展布方向来看，我国大陆明显地受印度板块和太平洋板块的控制，以印度板块的作用为最强烈；（２）内陆地区中强地震（Ｍｓ≥６．０）以上的地震形变的主要特征为：地震形变半径大（＞６００ｋｍ），范围广，震源地区形变图象特殊，而且形变值较大，为正常量值的数倍。随着距震中距离的增大，其形变强度也逐步减弱，地震前后的形变在地震形变区域范围内均具有明显的弹性回跳特征，在震源区内也存在一定的剩余形变；（３）经济发达地区的地面沉降及形变日趋严重，现为十几毫米／年～几十毫米／年，由过去的点发展成面，又连成片。尤其是我国东部的沿海地区，沉降漏斗已连成网，地面标高日渐损失，现已表现为一种明显的灾害源或潜在灾害源。这种地面沉降的产生是由于过量开采地下水所致，其运动特点为下沉而不可逆，即使不过量开采地下水，也只能控制沉降而难以使其显效回升。

中国大陆及邻区大震的远距离相关现象

本文根据中国大陆及边邻M_(?)≥7.0地震活动的时空特点,讨论了大地震活动的远程关联现象,划分了6个相关地带。根据本文所划分的诸相关地带,可以对所研究地区大地震的活动形势作出大致的估计。

香港股市与内地股市的联动性研究

本文分3个阶段考察了香港回归以来,香港股市和内地股市之间的联动关系及其变化。协整分析表明,香港股市和内地股市之间存在长期的均衡关系,这种均衡关系在内地资本市场实行股权分置改革后更趋于稳定。Granger因果检验表明,香港回归以来香港股市和内地股市之间的引导关系在经历B股开放和股权分置改革后发生了变化。脉冲响应函数分析从动态的角度进一步验证了香港股市和内地股市之间的引导关系及其变化,并深入分析了单个变量的波动或冲击对其自身及另一变量的影响程度。

中国大陆整体无净旋转基准及其应用

通常分析中国大陆水平位移(运动)场所采用的参考基准均是相对于欧亚板块的.这个基准对于分析中国大陆的整体运动及其与欧亚板块运动的关系等是合适的,但在研究中国大陆内部及其周边地区的相对运动时,上述基准就不是很恰当.以'中国地壳运动观测网络'1 000余个GPS测站的复测资料(1999～2004)为基础,利用数值逼近理论等方法,给出了中国大陆整体水平运动的旋转参数及其一级块体的旋转参数,并用实际应用算例给予说明.

公民社会的培育与中国经济伦理的改善

20世纪90年代后期以来,中国的经济伦理状况在总体上已有一定改善,但存在的一些严重不道德经济行为已呈现出地区性和行业性的特征,而不是某种单一的、偶然的现象,因此是一种结构性的不道德经济行为。企业与地方政府或部门政府的利益联盟是这种不道德行为存在和蔓延的现实基础。面对市场和政府的力量在遏制结构性不道德经济行为方面的双重失灵,中国经济伦理的进一步改善既要立足于企业的自觉和政府、法律监管力度的加强,更要立足于能有力量对企业和政府进行监督并形成制衡的第三方,即公民社会的发展。