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利用GPS观测结果研究华北地区现今构造应力场 总被引:7,自引:1,他引:7
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进行了模拟。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 相似文献
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灵山地区地震活动性及构造应力场 总被引:2,自引:0,他引:2
本文以广西及其邻近地区较为丰富的历史及现今的地震资料为基础,用地震能流密度的方法对灵山地区的地震活动水平作了定量的研究。对该区地震的震源深度作了估计,并用多种方法对灵山地区的构造应力场作了较详细的研究。 相似文献
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华北地区震源断层与深浅构造关系的初步研究 总被引:8,自引:0,他引:8
使用地震资料(等震线、地表破裂带、地形变、余震平面和剖面分布及震源机制)描述强震震源断层的立体特征。发现震源断层的上界即为由地震测深资料得到的G界面,并与该界面之下的高倾角深断裂吻合,证明地震时深断裂发生了剪切错动。震源断层与G界面之上的铲形正断层构成不连接的两套断裂系统,它们之间存在有对应和无对应的复杂关系。 相似文献
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乌鲁木齐地区构造应力场与中强震活动特征研究 总被引:14,自引:4,他引:10
为了做好中强地震的震预报和震后趋快速判定工作,利用乌鲁木齐地区中强震震源机制解,小震平均震源机制解以及S波偏振方向综合研究了该区域应力场的分布和中强地震的活动特征。 相似文献
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长江峡东地区构造应力场与地震活动的讨论 总被引:3,自引:0,他引:3
本文在分析峡东地区中、新生代构造应力场演化的基础上、根据构造形变、水系分布、震源机制与地球物理场特征和应力实测、模拟实验等多种途径综合分析了现代构造应力环境,认为本区现今处在大范围引张力背景上迭加了北东-南亚向压应力的联合作用,由此决定了中强地震的活动特点及其发震断裂系统。 相似文献
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Introduction Analyzing tectonic stress field based on focal mechanism data is an important way to the study tectonic evolvement of lithosphere and associated dynamic process. Such studies growrapidly in China and abroad (Zoback, 1992; Plenefisch, Bonjer, 1997; XU, 1985; CUI, XIE, 1999). At present most of the studies focus on the inversion of focal mechanism data for the direction and relative magnitude of stress tensor, and few on absolute stress. Using focal mechanism and fault scratch,… 相似文献
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Direction and structure characteristics of 58 tectonic stress tensors have been determined in 41 surveyed areas (points) in
the southwestern district of China through a calculation method for inversion of tectonic stress tensors from sliding direction
of faults, and, in combination with seismic mechanism solution andin-situ stress measurements, the following characteristics of the recent tectonic stress fields in the southwestern district of China
have been defined: (1) the stress fields in this district have remained stable since the end of early to mid-Pleistocene;
(2) the effect of such tectonic stresses is mainly horizontal; (3) the orientation of the maximum principal stress axis shows
a trend of regular rotation from north to south, i. e. from NEE-SWW in northern Songpan and Longmen Shan areas to sub-EW in
the central part of western Sichuan, and further to NNW-SWW or sub-SN in Yunnan; (4) the regional tectonic stress fields are
of distinct division character; (5) there is well concordance between the main direction and type of stress structures in
the stress tate both in deep and shallow parts of the crust. In addition, studies of staged tectonic stress tensors preliminarily
show that in early Quaternary the southwestern district was mainly affected by lateral compression of Indian plate, under
which the regional tectonic stress fields mainly display NE-sub-EW compression.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 407–417, 1993. 相似文献
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Three dimensional tectonic stress field in North China 总被引:3,自引:0,他引:3
IntroductionThecrusttectonicstressfieldisoneofthekeyproblemsofgeodynamics,itsmaincontentsareaprobingintospatialdistributionanddynamicevaluationofcrusttectonicstressfield,thentracingtheevolutionprocessofcrusttectonicmovement,learningcontemporarycrusttectoniceventanditsmechanism,thuspredictingthefuturedevelopmentlawoftectonicmovement.Intheendof1970s,aseriesofpaperswerepublishedattheinternationalconferenceonMagnitudeofDeviatoricStressesintheEarth'SCrustandUppermostMantle.Theygavethebriefoutlin… 相似文献
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兰州—玛曲地区是印度板块北东向推挤引起青藏块体强烈变形的前缘区,该区的现今构造应力场研究对研究大陆动力学问题具有重要意义.本文给出了兰州—玛曲地区不同地点的现今地应力实测值的大小和方向.测量方法采用压磁应力解除法,测点分别布置在阿姨山、大水、尕海、玛艾以及清水.为系统研究本区及邻近地区现今构造应力场特征,对已有应力实测数据进行了整理分析.研究结果表明,本区及邻区几十米浅表部应力与其他地区相比,属于中等大小量值;应力随深度增加而加大,但在不同构造单元,应力增加梯度有所不同;最大水平主应力方向总体上为北东向,不同构造单元上方向有所不同,鄂尔多斯地块最大水平主应力方向为近东西向,河西走廊带最大水平主应力方向在北北西—北东方向内变化,祁连山东南端最大水平主应力方向变化较大,西秦岭地块是现今地应力的一个过渡带,最大水平主应力方向由北侧的NE向逐渐转变为中部的EW向和南侧的SEE向.本文给出的结果与由GPS观测给出的该区域应变场分布具有一致性. 相似文献
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Recent tectonic stress field zoning in Sichuan-Yunnan region and its dynamic interest 总被引:7,自引:0,他引:7
In this paper, we have carefully determined the stress zones in the Sichuan-Yunnan region with reference to the in-situ stress data of hydraulic fracturing and the inverted fault slip data by using the step-by-step convergence method for stress zoning based on focal mechanism solutions. The results indicate that the tectonic stress field in the Sichuan-Yunnan region is divided into 3 stress zones by 2 approximately parallel NNW-trending stress transition belts. The area between the 2 belts is the Sichuan-Yunnan stress zone where the maximum principal stress σ1 is just in the NNW direction. The eastern boundary of Sichuan-Yunnan stress zone (the eastern stress transition belt) is basically consistent with the eastern boundary of Sichuan-Yunnan rhombic block. The western boundary of Sichuan-Yunnan stress zone (the western stress transition belt) is not totally consistent with the western boundary of Sichuan-Yunnan rhombic block. The northern segment of the western stress transition belt extends basically along the Jinshajiang fault and accords with the western boundary of Sichuan-Yunnan rhombic block, while its southern segment does not extend along the southwestern boundary of the rhombic block, i.e., Honghe fault and converge with the eastern stress transition belt, but stretches continuously in the NNW direction and accords with the Yingpanshan fault. We therefore consider that under the combined influence from the northward motion of India Plate, the southeastward shift of east Qinghai-Xizang Plateau and the strong obstruction of South China block, the tectonic stress field in the Sichuan-Yunnan region might not be totally controlled by the previous tectonic frame and new stress transition belt may have possibly formed. 相似文献
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IntroductionThe research on stress field interior the Earth is an either relative old or young branch of geoscience. Early in the 20th century, in order to learn the state of inner stress field, a few scholars had used simple ideal model to analyze big scale tectonic conformations and activities according to tide, gravity, rotation and inner thermal materials. So far, lots of problems on the state of the Earth stress field have not been solved completely yet. The origin of stress field, the d… 相似文献
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IntroductionSouthwest Yunnan region is located in the southeastern margin of Qinghai-Tibet Plateau, bordering on the Sichuan-Yunnan rhomboidal block in the east and on the northeast corner of Indian Plate in the northwest. It is one of the regions of intense tectonic activities and frequent strong earthquakes in China continent. To study the features of modern tectonic stress field of this region is of significance for revealing the evolution mechanisms of Tibetan Plateau as well as for un… 相似文献