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1.
利用2004~2013年GPS速度场数据,分析青藏块体东北缘的应变场和剖面应变积累特征。结果显示:1)稳定的阿拉善地块及鄂尔多斯地块分别阻挡了祁连山断裂带与贺兰山构造区分别向NE、E方向的物质迁移;2)主压应变率、最大剪应变率高值区均分布在祁连山构造带东段、海原断裂东段至六盘山断裂西段,面膨胀率压性高值区主要在祁连山构造带东段,3)祁连山断裂东段显示为以压性为主、兼具左旋走滑,海原断裂东段至六盘山断裂西段则表现为以左旋走滑为主、压性为辅的相对运动特征。  相似文献   

2.
利用2004~2013年3期GPS速度场数据,从断裂两侧的水平挤压、拉张与走滑等3方面,对海原断裂东段至六盘山断裂西段GPS剖面变形与应变积累进行研究。结果表明:1)海原断裂东段与六盘山断裂西段在运动方式上具有较强的一致性;2)在近10 a时间尺度上,该活动断裂整体表现为以左旋走滑为主,兼顾压性变化的运动特征,在上、下盘的相对运动差异速率上,走滑方向上达到2.0~5.5 mm/a,断裂垂直方向上约为0.5~3.0 mm/a。  相似文献   

3.
海原-六盘山弧型断裂及其附近最新构造变形演化分析   总被引:4,自引:0,他引:4  
利用两时段GPS速度场,用三维非线性有限元方法研究了海原-六盘山弧型断裂带及其附近最新构造变形演化特征。研究得到:1)海原-六盘山断裂带整体表现为左旋运动,海原断裂带左旋活动速率在(2~5.5) mm/a之间,六盘山断裂左旋活动速率约为1.0 mm/a;2)海原断裂带与六盘山断裂带的交接处目前处于强闭锁状态,亦是运动变形差异相对强烈、应变能积累较快的区段,存在强震孕震背景。  相似文献   

4.
基于弹性薄片格林函数的GPS三维应变求解方法,对青藏高原东北缘地区的构造变形特征进行研究。结果表明,青藏高原东北缘的应变主要集中在边界断裂上,而在断裂之间的内部块体应变分布相对较小,垂直应变最大值位于日月山断裂以东和海原断裂以南的区域,与块体旋转及物质东向运移有关,且很可能受中下地壳流的影响。本文用三维GPS应变分析为理解大陆内部构造变形动力学过程提供了新的视角。  相似文献   

5.
利用1999~2021年的GPS观测资料研究2022年门源6.9级地震震中附近区域的地壳形变特征。速度场在祁连山-海原地震带两侧呈现出明显的“南大北小”特性。发震断层速度剖面结果显示,断层两侧挤压速率为3.1 mm/a,走滑速率为3.9 mm/a,这与走滑为主的震源机制解一致。门源地震位于主应变率场和面膨胀率场高值区向低值区过渡的梯度带上,发生在最大剪应变率场和应变率第二张量不变量高值区边缘地区。同震库仑应力触发了大部分的余震,对冷龙岭断裂到海原断裂的地区有一定的应力加载作用。综合地壳形变特征和库仑应力等分析结果认为,冷龙岭断裂到海原断裂地区的地震危险性有所提高。  相似文献   

6.
对鲜水河断裂南段康定和石棉两个剖面的GPS观测结果的研究表明:离断层较近的站点,由汶川地震前的左旋走滑变为震后的右旋走滑、震前的挤压变为震后拉张;不管是右旋走滑量、拉张量,还是影响范围,汶川地震对石棉剖面的影响明显大于对康定剖面的影响;由于鲜水河断裂南段具有左旋走滑背景,汶川地震的发生在一定程度上缓解了鲜水河断裂南段的地震危险性.  相似文献   

7.
根据青藏高原东缘2004~2007年的GPS观测资料,通过多面函数法建立青藏高原东缘地壳水平运动速度场模型,给出球面坐标系下的视应变场。对照该区同期发生的地震活动,讨论了水平运动、应变场空间分布与强震和区域构造变形的关系。结果表明,松潘块体东西向地壳缩短显著,川滇块体以左旋剪切变形和顺时针转动为主。地应变特征表明,2008年汶川地震前龙门山地区为面应变能次高值区,呈面压特性,应变快速积累,龙门山断裂带中段震前处于闭锁状态。鲜水河断裂带西段南北地壳呈北东-南西向挤压缩短,东段两侧呈北西-南东向压缩。川滇菱形块体为应变能和面应变率梯度高值区,金沙江西部的应变能次高值区与羌塘块体的构造应力作用有关。  相似文献   

8.
基于Sentinel-1卫星数据,利用InSAR技术获取鲜水河断裂带2015~2018年的震间形变速率场。研究表明,InSAR结果的可靠性较高,且与GPS监测结果具有很好的一致性。形变速率场显示,鲜水河断裂具有明显的左旋走滑运动特性,断层滑动速率约为7~11 mm/a,自北向南存在递减趋势,且在2014-11 M6.3康定地震附近,由于受到震后余滑影响,滑动速率达到15 mm/a。  相似文献   

9.
通过对尼泊尔MS8.1地震前后附近区域GPS台站记录到的观测数据进行处理,获得了震区以及中国青藏高原地区地震前后GPS站点速度场以及震后形变场。震前速度场显示,喜马拉雅构造带整体呈现出约16 mm/a的压缩特征。同时,震前喜马拉雅构造带根据形变特征可分为东、中、西3段,其地震发生在中段,主要以北向挤压为主,而东西两段分别具有逆时针旋转和顺时针旋转的特征。震后GPS站点形变场显示,此次地震对中国新疆、青海、西藏等地区的影响较大,其最大震后位移达20 mm左右。震后速度场显示,本次地震对尼泊尔地区以及中国藏南地区的构造形变影响较大,主要表现为喜马拉雅构造带的年推挤速度减小,藏南地区的南北向运动速率减小,而东西向速度有增大的现象。这一现象可能对藏南地区的走滑断层有较大影响。  相似文献   

10.
鲜水河断裂带的构造大地测量   总被引:2,自引:2,他引:0  
利用短边GPS点阵、短基线标石阵和精密激光测距 ,在与鲜水河断裂带的断层破裂带垂直的剖面上和构造盆地内进行构造大地测量 ,获得了断层软弱带和断层蠕变带上的最佳形变分布。综合利用相关地学成果和理论 ,揭示了构造形变所隐含的动力学信息 ,识别了断层应变带、塑性流变带和主断面在地面的分布范围。用外围GPS远场联测成果探讨了该断裂带的驱动力机制 ,匡正了其“左旋”运动和现今活动速度的含义。最后 ,评估了该断裂的地震活动趋势  相似文献   

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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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《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   

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<正>The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research  相似文献   

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