长岛地区构造环境剪应力场的分布特征

利用山东数字地震台网记录资料,根据陈培善等用地震发生的断裂力学模式和震源谱理论,导出的震源处峰值加速度与构造环境剪应力值的关系,计算了山东长岛地区发生的中小地震构造环境剪应力值,并对应力场的分布状况和时空变化进行了分析。结果表明：剪应力τ值随矩震级（ML）的增大而增大,对两者作拟合得到它们之间较简单的关系为：τ=1.8...     

山东及附近海域构造环境剪应力场分析

利用山东数字地震台网的地震波形记录,选取2007年以来台网记录清晰的M_L≥2.0数字地震波形资料,计算每次地震的环境剪应力值τ_0和矩震级M_W,并分析其相关关系;结合山东地区地质构造和地震活动性特点,对胶东半岛及北部海域、南黄海北部地区、沂沭带地区、冀鲁豫交界地区应力场分布和时空变化进行细致分析,并探讨其区域特征及与地震活动性的关系。     

山东及附近海域构造环境剪应力场分析

利用山东数字地震台网的地震波形记录,选取2007年以来台网记录清晰的ML≥2．0数字地震波形资料,计算每次地震的环境剪应力值τ0和矩震级MW,并分析其相关关系;结合山东地区地质构造和地震活动性特点,对胶东半岛及北部海域、南黄海北部地区、沂沭带地区、冀鲁豫交界地区应力场分布和时空变化进行细致分析,并探讨其区域特征及与地震活动性的关系。     

峰值速度和加速度对环境剪应力的依赖性

从导出的地震定标律和地震破裂过程的断裂力学模式出发,得到了震源平均位移、速度和加速度谱的表达式,进而又推导出震源的峰值位移d_m,速度v_m和加速度a_m的表达式:d_m=k_dM_0~2/~3τ_0~(2/3),v=k_vM_0~(1/3)τ_0~(4/3),a_m=k_aτ_0~2式中M_0是地震矩,τ_0是环境剪应力值,k_d,k_v,k_a为适当的常数.我们选用了66个地震的观测资料,这些地震的矩震级范围包括了从1级左右的极微震,3—5级的小震,直到6—7级的大震;地震矩从10~9—10~(20)Nm,跨越了10个数量级,并用这些地震检验了上述公式. 令所有地震的平均应力为5MPa,定出常数k_d,k_v,k_a,进而由速度和加速度观测资料求得66个地震的环境剪应力τ_0值,这些数值相当稳定.多数极微震的τ_0值在2—4MPa之间;小震的τ_0值多数在4—8MPa左右;大震的τ_0值为10MPa左右。τ_0值对震源深度和断层类型有明显的依赖性.一般深度很浅的小震和极微震,τ_0值很低;正断层地震的τ_0值相对较低;逆断层地震的τ_0值较高;走滑断层地震的τ_0值则居中.     

峰值速度和加速度对环境剪应力的依赖性

从导出的地震定标律和地震破裂过程的断裂力学模式出发,得到了震源平均位移、速度和加速度谱的表达式,进而又推导出震源的峰值位移d_m,速度v_m和加速度a_m的表达式:d_m=k_dM_0~2/~3τ_0~(2/3),v=k_vM_0~(1/3)τ_0~(4/3),a_m=k_aτ_0~2式中M_0是地震矩,τ_0是环境剪应力值,k_d,k_v,k_a为适当的常数.我们选用了66个地震的观测资料,这些地震的矩震级范围包括了从1级左右的极微震,3-5级的小震,直到6-7级的大震;地震矩从10~9-10~(20)Nm,跨越了10个数量级,并用这些地震检验了上述公式. 令所有地震的平均应力为5MPa,定出常数k_d,k_v,k_a,进而由速度和加速度观测资料求得66个地震的环境剪应力τ_0值,这些数值相当稳定.多数极微震的τ_0值在2-4MPa之间;小震的τ_0值多数在4-8MPa左右;大震的τ_0值为10MPa左右。τ_0值对震源深度和断层类型有明显的依赖性.一般深度很浅的小震和极微震,τ_0值很低;正断层地震的τ_0值相对较低;逆断层地震的τ_0值较高;走滑断层地震的τ_0值则居中.     

汶川8.0级地震环境剪应力特征研究

基于甘肃强震固定台和流动观测记录的汶川8.0级地震主震及余震加速度资料,选用三分向记录均完整的87次地震(震级范围为3.0~8.0级),根据用位错理论二维断裂模式推导的震源峰值加速度与环境剪应力关系式计算汶川地震序列的环境剪应力值,探讨其环境剪应力场特征。结果表明,环境剪应力和矩震级有较好的相关性,3~5级地震对应的应力值多在3~6 MPa,5~6级多在6~9 MPa,6~7级多在9MPa以上,且环境剪应力对震源深度也有较强的依赖性。     

甘肃地区构造环境剪应力场对峰值加速度的影响

利用松潘—平武、肃南、共和等７３个地震２２８条强震加速度记录，根据陈培善先生提出的理论计算公式［１］，算出剪应力值并结合其发震构造环境研究了环境剪应力场对峰值加速度的影响     

陕西地区环境剪应力的分布特征

利用西安数字地震遥测台网记录的宽频带数字地震资料，测定了陕西地区环境剪应力值τ0的分布，结果显示陕西地区存在着环境剪应力值τ0的高值区，最后对其与地质构造和地震活动性之间的关系进行了探讨。     

云南地区部分地震的环境应力场特征

利用所获取的云南地区强震加速度观测资料,选取了其中具有震源深度参数及三个方向记录都完整的84次地震,震级范围为3．0～7．6级,震中距为几公里至几十公里(个别为100多公里),根据陈培善用位错理论二维断裂力学模式推导的震源峰值加速度与环境应力场关系式,计算了云南地区部分地震的环境剪应力值,并探讨了云南部分地震的环境应力场特征。     

武定地震序列剪应力场的时空分布特征

根据陈培善和Ｄuda提出的具有3模型的谱衰减模式,利用云南武定M ＝6.5地震序列的近场数字化记录资料,研究了近场地面运动峰值位移dm、峰值加速度am参数与环境应力t0值的依赖性．一个新的考虑是假定峰值参数与介质犙的相关性,并由此导出了用３种地面运动峰值参数测定环境应力t0值的３个关系式．用这些关系式计算了武定地震序列的环境应力t0值．结果表明,３个关系式计算的t0 值基本一致,绝大多数地震的平均t0值在5.0～35MPa的范围,属高应力值地震序列;高应力值被限制在紧靠主震震中附近的较小范围内,环境应力值的等值线的精细结构分布与强余震密切相关．对t0值的时空特征分析表明,该地震序列是在特定的地震构造交汇部位和高应力背景下发生的地震破裂过程．     

安徽及邻区构造环境剪应力场的研究

利用安徽省7个台站近2年来数字化地震观测资料，根据地震发生的断裂力学模式和震源谱理论，计算了安微及邻区42个中小地震的构造环境剪应力值，并对应力场分布状况及变化情况进行了分析研究。结果表明，安徽及邻区目前构造环境剪应力场水平总体上相对较低，但局部地区巳具备性中等地震的应用力场条件。     

The dependence of response spectrum on the tectonic ambient shear stress field

Introduction The acceleration response spectrum and peak ground acceleration are the necessary and im-portant parameters in earthquake-resistant design at present. They are still active research field. With the increase of digital high accurate strong motion observation data, especially the earth-quakes of Loma Prieta (M=7.0) in 1989; Landers (M=7.3) in 1992; Big Bear (M=6.4) in 1994 and Northridge (M=6.7) in 1994 in USA; Kozani (M=6.6) earthquake and afteshocks in 1995 in Greece; Dinar…     

A comparison of tectonic ambient shear stress value in China with that in western USA

Introduction The stress status of the earths crust is closely related to global structure, the direction of plate movement, the drive mechanism of plate, earthquake cause, etc. Therefore the researches of the stress status of the earths crust and the process of dynamic evolution are paid a great attention to by many people around the world (Zoback, Zoback, 1980; Zoback, et al, 1989; Zoback, 1989; Spence, 1997; Fuchs, 1997; Plenefish, Bonjer, 1997; Muller, et al, 1997; XU, et al, 1989; WAN…     

区域构造应力场的某些变化特征

应用现代中小地震的震源机制解 ,以山东地区为例 ,推断了该区的现今构造应力场 ,分析了区域构造应力场整体与局部变化特点。在此基础上 ,探讨了区域构造应力场与地震活动的关系     

he dependence of response spectrum on the tectonic ambient shear stress field

It has been analyzed the influence of the tectonic ambient shear stress value on response spectrum based on the previous theory. Based on the prediction equation BJF94 presented by the famous American researchers, CLB20, a new prediction formula is proposed by us, where it is introduced the influence of tectonic ambient shear stress value on response spectrum. BJF94 is the prediction equation, which mainly depends on strong ground motion data from western USA, while the prediction equation SEA99 is based on the strong ground motion data from extensional region all over the world. Comparing these two prediction equations in detail, it is found that after BJF94's prediction value lg(Y) minus 0.16 logarithmic units, the value is very close to SEA99's one. This case demonstrates that lg(Y) in extensional region is smaller; the differences of prediction equation are mainly owe to the differences of tectonic ambient shear stress value. If the factor of tectonic ambient shear stress value is included into the prediction equation, and the magnitude is used seismic moment magnitude to express, which is universal used around the world, and the distance is used the distance of fault project, which commonly used by many people, then regional differences of prediction equation will become much less, even vanish, and it can be constructed the universal prediction equation proper to all over the world. The error in the earthquake-resistant design in China will be small if we directly use the results of response spectrum of USA (e.g. BJF94 or SEA99).     

Discrimination between nuclear explosions and earthquakes based on consideration of tectonic ambient shear stress values

IntroductionFor the need of a nuclear test ban treaty, international society must make great efforts to find effective methods for discrimination between earthquake and nuclear explosion. Thereupon, many methods of discrimination of nuclear explosion appeared. But, at present, there is some uncertainty to discriminate middle or small nuclear explosion (Peppin, McEvilly, 1974; Richards, Zarales, 1990). When we study tectonic ambient shear stress field of Southern California, we find that str…     

利用怀来小孔径数字地震台网资料研究北京地区构造环境剪应力场

利用数字化地震台网资料研究构造环境应力场,可以把原来仅限于使用震震级ｍｂ≥３．８的地震资料扩大到Ｍｗ＝１．８,这样大大增加了对于目前地震活动性较弱地区地震资料的使用,加强了对于一些重点地区潜在危险性的研究。     

Basic characteristics of recent tectonic stress field in southwest China

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.     

The techniques of inverse for tectonic stress field in Chao-Shan area using data of sliding faults

The neotectonic stress field in Chao-Shan area is analyzed with the fault striation analysis method. At least four types of stress states are detected, which are in close connection with their locations relative to the basin. Generally, from the subsidence centres to places far from them, horizontal tectonic stress varies from tensile to compressive. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 36–41, 1992.