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1.
Adrian E. Scheidegger 《Surveys in Geophysics》1981,4(3):233-253
The neotectonic stress field in the Alpine-Mediterranean region is investigated. It is shown that information on this field can be obtained from insitu measurements, from earthquake fault plane solutions, from the orientation of joints and even from valley trends. The available data are collected and collated. It is shown that there is a general correspondence in any one area between these types of data. Maps showing the orientations of the principal stress directions are given. 相似文献
2.
长江三峡地区新生代以来地壳应力场的基本特征 总被引：2，自引：0，他引：2
根据白垩－第三纪红层中构造变形实际观测及水系统计资料，计算了三峡地区新生代和新构造期分区及区域应力场的主应力方向。结果表明：方压应力为北东东向，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。 相似文献
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4.
青海东部地区新生代构造应力场探讨 总被引：2，自引：0，他引：2
利用地质、地震、测量及地貌资料确定了青海东部地区的新构造应力场的主应力方向,自新第三纪以来,该区地壳构造应力场相对稳定,可能是印度板块与欧亚板块相互作用的结果。 相似文献
5.
Introduction Anisotropy of the crust is a common phenomenon(Crampin,1984).Shear-wave splitting can be used to study the earthquake anisotropic characteristic in crust,to analyze crustal stress field condition,and to describe the static and the dynamic state of the related anisotropic parameters(GAO et al,1999).Shear-wave splitting is quite sensitive to anisotropy.The domestic scholars applied shear-wave splitting to studying the crustal anisotropy(YAO et al,1992;GAO and FENG,1990).The st… 相似文献
6.
通过对云南遥测地震台网2000年1月1日——2003年12月31日4年资料的分析， 使用剪切波分裂SAM综合分析方法，获得了云南地区10个数字地震台站的快剪切波偏振结果. 结果表明， 云南地区大部分台站的快剪切波偏振优势方向主要为近N——S或NNW方向； 位于活动断裂上的台站的快剪切波偏振优势方向与活动断裂的走向一致；与GPS主压应变方向一致，与区域主压应力方向基本一致；少数台站的快剪切波偏振较为复杂，或与活动断裂的走向及GPS主压应变方向不一致. 这样的台站总是位于几个断裂的交会处，反映了复杂的断裂背景和复杂的应力分布特征. 快剪切波偏振优势方向代表了原地最大主压应力方向，受到区域应力场和断裂分布等多种因素的控制. 相似文献
7.
In this paper, the lithosphere is considered to be a homogeneous elastic spherical shell for the sake of simplicity and the stress equations for the base of the lithosphere are taken as boundary conditions. Then the stress equations are obtained for use in the computation of the stress field in the lithosphere with the satellite gravitational harmonic coefficients. The 5 × 5° global stress field in the lithosphere is computed from harmonics of 2–30°. The directions of principal stresses of this stress field agree favourably with the directions of principal stresses indicated by mid-plate earthquake mechanisms, in situ stress measurements and sensitive geological features. This result indicates that the drag forces exerted on the base of the lithosphere, due to gravitational mantle convection, may be among the driving forces of plate motion and a major source for the stress field in the lithosphere. 相似文献
8.
Crustal seismic anisotropy in Yunnan, Southwestern China 总被引：5，自引：0，他引：5
Using seismic data recorded by Yunnan Telemetry Seismic Network from January 1, 2000, to May 31, 2005, the polarization directions
of fast shear waves are obtained at 15 seismic stations by SAM technique, which is a systematic analysis method on shear-wave
splitting. The results show that predominant directions of polarizations of fast shear waves at most stations are mainly nearly
in the N–S or NNW directions in Yunnan. The predominant polarization directions of fast shear waves at stations located on
the active faults are consistent with the strike of active faults, directions of regional principal compressive strains from
GPS measurement, and directions of regional principal compressive stress. A few of the stations show that polarization patterns
of fast shear waves are more complicated or inconsistent with the strike of active faults and the directions of principal
GPS compressive strains; these stations are always located at the junction of several faults. We conclude that the predominant
polarization direction of fast shear waves indicates that the direction of the in situ maximum principal compressive stress
is controlled by multiple tectonic aspects, such as the regional stress field and faults. 相似文献
9.
L. A. Sim N. A. Sycheva V. N. Sychev A. V. Marinin 《Izvestiya Physics of the Solid Earth》2014,50(3):378-392
The study of neotectonic stresses of the North Tien Shan is carried out within the northern slopes of the Kyrgyz Ridge bordering the Chyua submontane depression. The purpose of the study was to reconstruct the neotectonic stresses from the geological indicators and to compare the obtained results with the data on the present-day stress state of this region. The work is based on the analysis of the field in situ data acquired in the expeditions in 2009 and 2011. For the first time for the Northern Tien Shan region, the general (averaged) neotectonic stresses, which are distinct between the uplifts and depressions, are reconstructed. The deformation of the positive topographic features at the recent tectonic stage takes place in the conditions of thrust faulting with the meriodional horizontal compression axis and subvertical tension axis, while deformation of the negative landforms is dominated by normal faulting with the vertical compression axis and northnortheast trending subhorizontal tension axis. Based on the field data, separate sites with different types of local stress tensors, which are determined by the Lode-Nadai parameter, are revealed. The neotectonic geodynamical regime within the depressions and uplifts and the variations in the type of the stress tensor agree with the characteristics of the present-day stress state reconstructed from seismological data. 相似文献
10.
This paper approaches the neotectonic stress field based on the data of foeal mechanismsolution,ground stress measurement,tectonic mechanical analysis and geodetic surveying,and finds out that the orientations of the maximum principal comproessive sterss patterns arequite discordant with different methods and the stress patterns are widely differnt betweenthose in the shallow and deep part of the crust in North China.Based on the analysis ofabove-mentioned data,we established a duplex model by considering the diversities of theStress patterns in 3-dimentional spaces,the boundary conditions and the lithospheric media,and made an inverse calculation by using the finite element method.The calculated results fitwell with the reality in North China,i.e.the stress patterns in lower crust which is below thedetachment interface at the deptp of 10 km from ground surface are relatively consistent withnearly horizontal state and NE-ENE trending of the maximum principal compressive stressaxes,whereas the stress patt 相似文献
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From focal mechanism solutions of the earthquakes in the northern part of North China during the period of 2002～2006,the directions of principal stress axes in 4 stress sub-districts are analyzed using a grid test method.The characteristic of present crustal stress directions is discussed.Based on this result and on the focal mechanism solutions calculated for some events in the period of 1977～1998,in combination with some other study results,the temporal variation of present crustal stress directions in the northern part of North China is investigated.The re-sults confirm that the direction of crustal principal stress in some regions had somewhat rotated after the 1976 Tangshan M7.8 earthquake.The mean P axes of the focal mechanism solutions rotated clockwise not only in Tangshan sub-district,but also in Beijing and Xingtai sub-districts after the Tangshan earthquake.In Beijing and Xingtai sub-districts the orientations of principal stress axes in the period of 2002～2006 are consistent with that before the Tangshan earthquake,implying that the stress orientations has rotated back to the state before the Tang-shan earthquake in these two sub-districts.The directions of the mean P axes are nearly E-W in Tangshan sub-dis-trict since the M7.8 earthquake.The present stress field in the sub-district northwest to Beijing,or in the western part of the Zhangjiakou-Bohai fault zone,is relatively stable during the time period concerned in this study.Because of the limitation of data,this paper only states a possible variation of stress field in the northern part of North China in the recent decades. 相似文献
13.
本文通过近年来,在京津唐地区取得的大地测量资料,研究本区现代构造运动,指出了北北东—北东向、北西向及东西向三组构造最为活动。它们是受近于水平方向北北西—南南东向主张应力和北东东—南西西向主压应力的应力场所控制,并以主张应力大于主压应力的作用方式出现;而又受深部构造的断块上拱和断陷的影响 相似文献
14.
Introduction The present Bohai Sea is a half-closed shallow one in the continent, located at the northeast to North China, with an area about 7.3104 km2. Geologically, it is situated in the northern North China basin and of a short development history. Previous studies (WANG, LI, 1983; Institute of Oceanology, Chinese Academy of Sciences, 1985; HUANG, et al, 1993) show that the Fu-jian-Lingnan uplift in the East China Sea continental shelf sank gradually into the oceanic bottom, mak… 相似文献
15.
V. A. Petrov Niu Anfu V. B. Smirnov A. O. Mostryukov Li Zhixiong A. V. Ponomarev Jiang Zaisen Shen Xuhui 《Izvestiya Physics of the Solid Earth》2008,44(10):846-855
Orientations of the principal axes of the tectonic stress field reconstructed from seismological data on focal mechanisms of earthquakes and strain fields determined from GPS measurements in China are compared. The data of GPS measurements used in the paper were obtained by the Crustal Movement Observation Network of China (about 1000 stations) in the period of 1998–2004. On the basis of information on the recent horizontal crustal motions, the strain field is calculated for the study territory by the finite element method. Calculations of the strain tensor using GPS data were carried out with a step of 1° in latitude and longitude. A catalog of earthquake focal mechanisms was used for the reconstruction of tectonic stress field components. Focal mechanisms of earthquakes were calculated with the use of seismological data on signs of first arrivals from the bulletin of the International Seismological Center. To estimate characteristics of the regional stress field, an approach based on the kinematic method proposed by O.I. Gushchenko was applied. The tectonic stress field was reconstructed in depth intervals of 0 < H < 35 km and 35 km < H < 70 km from data on focal mechanisms of earthquakes over the periods of 1998–2004 and 1985–2004. Comparison of directions of the principal strain axes at the surface (according to GPS measurements) and directions of the principal stress axes (reconstructed from focal mechanisms of earthquakes) showed their good convergence. Seismotectonic strains and GPS measurements coincide within a larger part of the territory. The coincidence is best in a depth interval of 0 < H < 35 km. Maximum misfit values are confined to areas of high 3-D gradients of strain axis directions and are possibly related to the structural heterogeneity of the region, zones with strains of the same type along both horizontal axes (compression or extension along all directions), or areas of small absolute values of recent horizontal movements. Areas with invariable directions of the stress axes are recognizable regardless of the depth of initial data. Good reproducibility of results obtained by two different methods made it possible to check the method of stress field reconstruction using data on focal mechanisms of earthquakes. 相似文献
16.
对中国大陆地壳水平变形的初步探索 总被引：13，自引：0，他引：13
根据全国ＧＰＳ网１９９４和１９９６年两期观测资料的处理结果,讨论了中国大陆地区现阶段应变场和应力场。青藏亚板块的西部和东部张应变起主导作用,中部压应变占优势,主压应变方向为北北东向;青藏亚板块东南部东南段云南地区的主压应变方向为北西向,压应变和张应变量级相当。新疆亚板块的主压应役北北东向至北东向为主,应变量存在差别。华北亚板块的主压应变方向是北东至近东西向为主导,局部地段存在差别,大部分地区压应变 相似文献
17.
根据华北地区61次中、小地震（3.0≤M≤5.5）和10次M≥6.0大地震的震源机制结果的统计分析,得到地震释能应力场的优势方向,主压应力轴为70°-80°,主张应力轴为340°-350°,它们的仰角基本上小于45°。这表明,华北地区处于以北东东向水平压应力和北北西向水平张应力为主的现代构造应力场中。指出了这一地区6级以上地震和震源深度大于17公里的中、小地震应力场方向一致性较好,可能更接近构造应力场方向。华北地区一致性应力场的南缘,可能在秦岭、大别山及长江下游一带。 相似文献
18.
利用动力学模拟方法研究地幔对流对于大尺度岩石圈内部应力场形成的作用. 地幔物质内部的密度横向非均匀及表面板块运动引起地幔流动,并在岩石圈底部产生一个应力场. 该应力场作为面力将造成岩石圈本身变形,从而产生岩石圈内部的应力分布. 模拟计算结果表明,大部分俯冲带及大陆碰撞带区域应力均呈现挤压特征,如环太平洋俯冲带及印度－欧亚碰撞带等;而东太平洋洋脊、大西洋洋脊及东非裂谷处应力状态均表现为拉张;并且绝大多数热点位置处于应力拉张区域,这与目前对全球构造应力状态的理解是一致的. 计算的岩石圈内部最大水平主压应力的方向与观测表现出相当的一致,其结果总体上吻合得较好,然而在局部区域（例如西北太平洋的俯冲带、青藏高原等地区）存在着较大的差异. 研究表明,地幔对流是造成岩石圈内部大尺度应力状态及分布的一个重要因素. 相似文献
19.
本文通过对红河断裂带附近水平残余应力应变场的分析和对该区用6种加力方向进行的平面有限元计算,并结合有关资料讨论了该区现今应力场及其地震危险性。结果表明:该区现今构造应力场较为复杂,且有明显的分区特点,但其最大主压应力的优势方位为近南北。永胜附近,剑川—洱源一带,大理、下关、宾川所围地区是该区未来地震的危险区。当主压应力轴偏向北西时,永平一带,兽洱—思茅一带,峨山、石屏、通海一带也可能发展成为未来地震的危险区。 相似文献
20.
We used the focal mechanisms of crustal earthquakes (depth <40 km) in the period 1909–2012 and the available GPS velocities, derived from the data collected between 1999 to 2011, to estimate the magnitude and directions of maximum principal stress and strain rates in Iran. The Pearson product moment correlation was used to find the correlation between the stress field obtained from the focal mechanism stress inversion and that obtained using the seismic and geodetic strain rates. Our assumption is that stresses in a continuum are produced by tectonic forces and the consequent deformation on the crustal scale. Therefore, the direction of the stress and strain (or strain rate) are ideally to be the same. Our results show a strong correlation between the directions of the principal components of stress and strain (rate) obtained using the different data/methods. Using weighted average analysis, we present a new stress map for Iran. 相似文献