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利用广义应变花法计算地应变场
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作者 朱守彪 《防灾技术高等专科学校学报》 2003年第2期1-7,共7页
根据GPS测量的速度计算地应变是地球动力学研究中非常有意义的一项工作,但计算时涉及数值微分,如何减小其计算误差是一个突出的问题。本文提出将工程测量中的平面应变花分析方法推广到地球球面上的广义应变花方法;并通过对已知位移和应... 根据GPS测量的速度计算地应变是地球动力学研究中非常有意义的一项工作,但计算时涉及数值微分,如何减小其计算误差是一个突出的问题。本文提出将工程测量中的平面应变花分析方法推广到地球球面上的广义应变花方法;并通过对已知位移和应变场的特例下的数值实验,比较常用的最小二乘配置法和广义应变花方法计算应变的精度。结果显示广义应变花法应变的计算精度比最小二乘配置法高。 展开更多
关键词 地应变场 广义应变花法 地球动力学 最小二乘配置法 GPS 地壳运动速度
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广义应变花方法及其在川滇地区地应变率场计算中的应用 被引量:3
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作者 朱守彪 石耀霖 《中国科学院研究生院学报》 CAS CSCD 2005年第3期292-302,共11页
提出将工程测量中的平面应变花分析方法推广到地球球面上的广义应变花方法 ;并通过对已知位移和应变场的特例下的数值实验 ,比较常用的最小二乘配置法和广义应变花方法计算应变的精度 .结果显示广义应变花法应变的计算精度比最小二乘配... 提出将工程测量中的平面应变花分析方法推广到地球球面上的广义应变花方法 ;并通过对已知位移和应变场的特例下的数值实验 ,比较常用的最小二乘配置法和广义应变花方法计算应变的精度 .结果显示广义应变花法应变的计算精度比最小二乘配置法高 .最后以中国川滇地区为例 ,利用GPS观测资料计算了地应变率场 ,并对计算方法和结果进行了分析讨论 . 展开更多
关键词 广义应变花方法 最小二乘配置法 GPS观测 地应变场 川滇地区
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青藏高原及邻区现今地应变率场的计算及其结果的地球动力学意义 被引量:44
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作者 朱守彪 蔡永恩 石耀霖 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2005年第5期1053-1061,共9页
许多研究人员利用GPS测量的速度资料计算了地应变率场,但其结果差异较大.本文将地质统计学中的Kriging方法引入到GPS观测的速度场研究中,通过Kriging插值得到青藏高原及邻区均匀网格节点上的速度值,然后运用有限单元中形函数(Lagrange... 许多研究人员利用GPS测量的速度资料计算了地应变率场,但其结果差异较大.本文将地质统计学中的Kriging方法引入到GPS观测的速度场研究中,通过Kriging插值得到青藏高原及邻区均匀网格节点上的速度值,然后运用有限单元中形函数(Lagrange插值函数)的求导方法,计算每个网格单元积分点处的地应变率分量,从而获得青藏高原及邻区的地应变率场的分布.计算结果显示,青藏高原主体处在南北向受挤压、东西向被拉张的应变状态之中,但高原东部地区则正好相反,即南北向拉张、东西向出现挤压.青藏高原及邻区主应变率的方位与震源机制解中P轴、T轴的方向基本一致;最大主压应变率的高值区分布在喜马拉雅主边界冲断带及附近地区,高原内部出现主张应变率大于压应变率的现象,且高原内部处在拉张应变状态.面膨胀率结果也表明,喜马拉雅山及附近地区为面收缩区,而高原内部其他地区主要为膨胀区;最大剪应变率分布清晰地显示出青藏高原周边的主要断裂带轮廓.文中的应变率计算结果预示青藏高原及周边地区现今的地应变与较长期的地质活动之间有一定的继承关系. 展开更多
关键词 KRIGING方法 GPS观测 地应变 青藏高原
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2011年日本东北大地震(M_W=9.0)震间与震前变形场特征及其对强震预测的启示 被引量:5
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作者 朱守彪 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2020年第2期427-439,共13页
强震震前(preseismic)动力学过程的研究对于地震预测具有十分重要的意义,但由于观测资料的限制,目前对强震前孕震区力学状态及其演化过程的认识还非常有限.2011年日本东北9.0特大地震(Tohoku-Oki)发生在GPS观测台站最为密集的地区,为研... 强震震前(preseismic)动力学过程的研究对于地震预测具有十分重要的意义,但由于观测资料的限制,目前对强震前孕震区力学状态及其演化过程的认识还非常有限.2011年日本东北9.0特大地震(Tohoku-Oki)发生在GPS观测台站最为密集的地区,为研究特大地震震间(interseismic)与震前的变形状态提供了难得的机会.文中将利用日本东北大地震之前连续的GPS观测资料,分别计算震间与震前的速度场与变形场.通过对比分析发现,日本东北地区(Tohoku)震前的应变状态与震间的有很大的不同,震间的变形主要受到太平洋板块向日本海沟北西西向的俯冲挤压作用所控制,其主压应变以近东西向压缩为主,日本东北地区的运动方向与太平洋板块的运动方向大体一致.但是,临近地震前(震前)日本东北地区的运动方向发生了很大变化,震前30天的连续GPS观测结果显示,速度场的优势方向经常变换,间歇性地出现与太平洋板块运动方向相反的情况.这意味着震前孕震区的力学状态发生了很大的改变.这种变化可能与震前破裂成核或慢滑移及慢地震等过程有关,这些过程将加速或促进大地震的发生,从而为大地震的发生准备了力学条件.值得特别强调的是,这些现象都是可以通过直接观测能够发现的大地震之前的异常现象.由此可见,加密GPS站点进行连续观测,寻找震前变形异常区以及探索异常的物理机制对于地震预测预报有重要的科学意义. 展开更多
关键词 2011年日本东北MW9.0大地震 GPS连续观测 震前变形 地应变 地震预测
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The Dynamic Characteristics of Strain Fields and Crustal Movement before the Wenchuan Earthquake (M_S=8.0) 被引量:1
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作者 Jiang Zaisen Wu Yanqiang Fang Ying Li Peng Wang Wuxing 《Earthquake Research in China》 2009年第3期257-265,共9页
In this paper, we analyze the crustal movements, strain field changes and large scale dynamic characteristics of horizontal deformation before the Wenchuan earthquake ( Ms = 8.0) using GPS data obtained from the Cru... In this paper, we analyze the crustal movements, strain field changes and large scale dynamic characteristics of horizontal deformation before the Wenchuan earthquake ( Ms = 8.0) using GPS data obtained from the Crustal Movement Observation Network of China. The following issues are discussed. First, the strain fields of the Longmeushan fault zone located at the epicenter show slow accumulation, because of the tectonic dynamics process subjected to the eastward movement of the Bayan Har block. Second, the different movements between the Longmenshan fault and South China block are smaller than the errors of GPS observation. Third, the high value of compressive strain (2004 - 2007) is located at the epicenter, which shows that the local squeezing action is stronger than before. Fourth, the data from GPS reference stations in the Chinese Mainland show that crustal shortening is faster than before in the north-eastern direction, which is part of the background of the local tectonic dynamics increase in the Longmenshan fault zone. 展开更多
关键词 Wenchuan earthquake Ms = 8.0 GPS Crustal movement Strain field Tectonic dynamics background
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Study on the Horizontal Deformation Strain Field in the Central and Northern Parts of Yunnan Province
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作者 Li Yanxing, Guo Liangqian and Zhang ZhongfuFirst Crustal Deformation Monitoring Center, CSB, Tianjin 300180, China 《Earthquake Research in China》 2003年第1期14-21,共8页
Based on the horizontal deformation field and the strain field derived from the GPS data over the period of 1999~2001 in the Yunnan area, the characteristics of deformation and strain in the northern part of Yunnan P... Based on the horizontal deformation field and the strain field derived from the GPS data over the period of 1999~2001 in the Yunnan area, the characteristics of deformation and strain in the northern part of Yunnan Province have been studied. The results indicate that the central part of the studied area is rather stable with little crustal displacement, while the western and eastern parts are active with larger displacement. The strain field reveals that the orientations of the principal compressive strain axis of the crust and the sub blocks in the area are NW SE, while the orientations of the principal tensile strain axis is NE SW. In the studied area, the tensile strain is predominatly in the northern part and the compressive strain is predominatly in the central and southern parts. The stretching direction of the shear strain contour is basically consistent with the strike of the active fault. The strain and stress fields of the fault activity are related to the structure where the fault is located, while the activity properties of the faults are different. 展开更多
关键词 GPS Deformation field Strain field
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Preliminary Study on Simulation of Global Seismic Activities with Global Strain Rate
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作者 Wang Wuxing Shi Yaolin 《Earthquake Research in China》 2014年第2期164-176,共13页
The relationship between the strain rate field observed by GPS and global distribution of strong earthquakes is analyzed in this work. How do we recognize the characteristics of global seismic activities with space ob... The relationship between the strain rate field observed by GPS and global distribution of strong earthquakes is analyzed in this work. How do we recognize the characteristics of global seismic activities with space observation technology? A preliminary model of Cellular Automata that could simulate the global seismic activities both in time and space has been established based on the results of global strain rate field provided by the GSRM Program. The grid of the model is evenly divided,which is consistent with that of GSRM.The status of each cell is its strain state,and is adjusted according to the evolution rules.Maximum shear strain criterion is adopted in the evolution of the Cellular Automata. The threshold for cells in surface expansion is 80% of that for those in compression. The preliminary model could in general simulate the main characteristics of the distribution of the global seismic activities. It could exhibit in general the global distribution of weak and active tectonic activities. Although the preliminary Cellular Automata model needs to be improved in many aspects,the result suggests the possibility of modeling the general features of rather complicated global seismic activities based on the strain rates obtained by GPS and other observations. 展开更多
关键词 Global strain rate Cellular Automata SIMULATION Seismic activity
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Estimation of Site Effects on Stations in the Capital Circle Region Using the Generalized Inversion Method
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作者 Shi Haixia Xiu Jigang +2 位作者 Chen Zhangli Wang Qincai Hua Wei 《Earthquake Research in China》 2010年第2期198-210,共13页
Generalized Inversion Method has been used to estimate the spatial variation of site effects,using the digital data of SH-waves recorded by 63 stations in the Capital Circle Region of China from 2001 to 2006.We gained... Generalized Inversion Method has been used to estimate the spatial variation of site effects,using the digital data of SH-waves recorded by 63 stations in the Capital Circle Region of China from 2001 to 2006.We gained the site effects of all stations participating in the calculation.We found that the site effect of rock was stabile and about 1.0 from 1.0Hz to 10.0Hz,while the site effect of deposit was high in low frequencies,about 3 ~ 7 from 1.0Hz to 8.0Hz,and the site effect was protuberant at about 5.0Hz,then fell as the frequency increased.The result shows the shape and intensity of station site effects are mainly influenced by the lithology below the station,and possibly also by the local geological structure. 展开更多
关键词 Capital Circle Region Site effects Generalized inversion method SH-wave Weighting factor
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Quantitative Seismic Risk Evaluation on Blind Faults in Offshore Areas of Tianjin,China
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作者 Liu Hongyan Chen Yukun +1 位作者 Yan Chengguo Yang Fei 《Earthquake Research in China》 2013年第4期542-552,共11页
Based on faults surveying and research data in the Tianjin offshore areas,through studying tectonic structure,Quaternary activity,deep structure,stress and strain fields and seismicity in the Tianjin offshore areas,th... Based on faults surveying and research data in the Tianjin offshore areas,through studying tectonic structure,Quaternary activity,deep structure,stress and strain fields and seismicity in the Tianjin offshore areas,the activity and tectonic features of the faults are determined synthetically.Using seismo-geological data,and the historical and modern seismicity data,the frequency-magnitude relationship model normalized by 500a is established and based on the relationship between the upper limit of maximum magnitude M u and a t/b,the maximum magnitudes of the sea section of the Haihe river fault and the Haiyi fault are calculated.Then Poisson probability model is adopted and the quantitative parameters,such as the maximum magnitude,occurrence probability,recurrence cycle of the faults in the south Tianjin offshore areas in the coming 50~200a,are calculated. 展开更多
关键词 Seismic risk Quantitative evaluation Fault sub-area Frequency-magnituderelationship Maximum magnitude Occurrence probability Recurrenceperiod
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