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1.
根据1992年和1995年两期GPS测量结果所获得的位移场和应变场,结合丰富的地质资料,利用有限元方法对华北地区现今构造应力场进行了数值模拟。计算结果表明:华北地区现今构造应力场主压应力方向为NEE,其边界力除受NE55°~SW235°方向的压应力作用外,同时还受到SE120°~NW300°方向的拉张力作用,其中NE-SW的压应力量值较大,约为SE-NW向拉应力的两倍,这个结果与震源机制解所获得的应力场方向基本一致。这一应力场状态是两种动力学过程的叠加:一是印度板块和太平洋板块的挤压,其中来自印度板块的作用力最大,约为太平洋板块作用力的1.5倍;另一个是因地幔隆起而产生的NW-SE向的水平拉张力。  相似文献   

2.
在系统测量褶皱、断层、节理、线理、擦痕等构造形迹位移参数的基础上,通过构造解析方法,获得了该区自古生代以来的四期构造应力场。四期应力场的方向及性质分别为:(1)以264°~290°方向挤压为主,辅以335°~15°方向拉伸的伸展期;(2)以360°~15°方向挤压为主的压缩期;(3)以50°~60°方向挤压为主的压缩期;(4)以340°~10°方向位伸为主,后辅以284°~295°方向位伸的伸展期。研究表明,四期构造应力场的特征与构造演化的表现是基本一致的。  相似文献   

3.
高精度GPS观测及其在福建东南沿海地壳形变研究中的应用   总被引:1,自引:1,他引:0  
对福建东南沿海GPS地壳形变监测网的两期观测资料的处理方法及其精度进行了深入讨论,并根据复测资料的对比,对该地区现今地壳运动的基本特征进行了初步的分析。结果表明两期GPS观测资料经严密处理后其基线重复性精度优于10- 8,高程分量的精度固定误差小于7m m ,比例误差优于10- 8,满足了研究该地区现今地壳运动的基本需要。利用统一处理后的两期GPS观测结果获得了该地区现今地壳运动的基本图象,表明该地区相对于全球ITRF框架整体呈南东东向运动,台湾和福建沿海大陆相对运动是北西向压缩。这个结果和本地区北西向主压应力的构造应力场状态一致。GPS测区范围内测点的相对运动表明测网所跨越的北东、北东东向断裂呈右旋走滑趋势,其活动量为毫米。  相似文献   

4.
对漳县含盐红层盆地的构造节理、褶皱等构造形迹进行野外观察、测量、分期配套,应用吴氏网赤平投影法来反演古构造应力场。分析表明,漳县红层盆地白垩系沉积地层形成后至少经历了4期构造活动:第一期构造应力场的最大主压应力方向为NW-SE向,第二期构造应力场的最大主压应力方向为NE-SW向,第三期构造应力场的最大主压应力方向近E-W向,第四期构造应力场的最大主压应力方向近S-N向,4期构造应力场中间主压力轴(δ2)多近于直立。反演结果显示,该区域自白垩系沉积后区域构造特征以走滑作用为主。  相似文献   

5.
长江三峡及邻区构造应力场和震源错动类型的研究   总被引:2,自引:2,他引:0  
在文献[3]提出的用计算机确定震源断层面解的基础上,进一步给出了解的置信度。置信度由两个因子组成(C_1,C_2)。其中C_1为初动符号的符合比,C_2为解的不可变动空间与全部空间的比。使用长江三峡及邻区(北纬28°-34°,东经108°-114°)1974年以来的初动观测资料,确定了Ms≥2.1的40次地震的断层面解、该区的区域应力场和分区应力场及平均错动性质。此外还给出了黄陵背斜地区的应力场特征。结果表明,黄陵背斜的地震构造活动具有整体性,构造过程发生在15~20km的深度,张应力轴的方向分布显示以背斜为中心的幅射状态。  相似文献   

6.
三峡及邻区新构造期以来应力场分区研究   总被引:3,自引:3,他引:0  
利用地形变测量、震源机制和钻孔应力测量等资料,综合研究了三峡及邻区的构造应力场。结果表明,研究区在大区域近东西向构造应力场作用下.新构造期一现代构造应力场的作用方向具有明显的分区性,即北区呈近北西西向挤压;西区呈北西向挤压;东区呈北东向挤压。  相似文献   

7.
根据点源孕震力学模型 ,应用福建 台湾地区GPS位移速度资料反演 1999年台湾南投Mw7.6大震前的孕震参数。反演所得的震中与实际发生的地震震中相差 6 7km ,主压应力场方向为 319.9°,倾角 - 2 8.6° ,即仰角2 8.6° ,与用震源机制解得到的P轴方向和倾角分别相差 17°和 8.6° ,与菲律宾板块向亚洲板块挤压的方向是一致的。用土耳其地区GPS位移速率资料反演 1999年土耳其Mw7.6地震前的孕震参数 ,反演得到的震中与实际震中相差 70km ,主应力方位角和倾角分别为 16 2 .5°、11.5°,与震源机制解结果分别差 2 4 .5°和 1.5°。  相似文献   

8.
为了研究三峡坝库区的地壳稳定性,根据奥陶-侏罗纪地层中构造变形的实际观测资料,计算了秭归龙会观5.1级震区及其邻区新生代以来区域应力场的主应力方向。结果表明:主压应力为北东东向,主张应力为北北西向;现代构造应力场与新生代以来应力场基本一致;晚第三纪以来,该区构造应力场相对稳定和统一。  相似文献   

9.
本区中新生代至少经历了三期构造应力场作用,印支期为近南北向挤压应力场,燕山早-中期为北东东-南西西向挤压应力扬,燕山晚期—喜山早期为北西—南东向挤压应力场。这三期应力场控制了盖层构造的形成与发展,改造了晚古生代煤层的赋存状况,使之在北西向向斜中形成北西展布的厚、薄煤条带。  相似文献   

10.
根据震旦一二叠纪地层中构造变形的实际观测及卫星影象解译资料,计算了清江隔河岩水库区新生代以来区域应力场的主应力方向。结果表明:主压应力为北东东向,主张应力为北北西向,现代构造应力场与新生代以来应力场基本一致。晚第三纪以来,该区构造应力场相对稳定和统一。  相似文献   

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12.
Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

13.
Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.  相似文献   

14.
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied  相似文献   

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16.
《山地科学学报》2014,(4):I0004-I0009
<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.  相似文献   

17.
<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by  相似文献   

18.
Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.  相似文献   

19.
The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.  相似文献   

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