苍山5．2级地震前地震波速比的异常变化   总被引：1，自引：1，他引：1  

周焕鹏  卢守安 《高原地震》1996,(1)

本文对苍山５．２级地震前，鲁南地区地震波速比的时、空分布特征进行了分析，发现５．２级地震前，该区波速比的时、空分布都出现了较明显的低值异常。时间分布的异常形态为下降—低值—恢复—发震。空间分布则为近似圆形的低值异常区。异常区外围地区显示地震平静。苍山５．２级地震前，我们曾根据该区的波速比异常变化，对鲁南地区提出了预报意见。  相似文献   

云龙台固体潮观测对地震监测能力的评价     

何翔 《高原地震》1996,(4)

对云龙台的水管倾斜仪观测数据进行了倾斜固体潮的潮汐分析，发现ＥＷ和ＮＳ两个分量的振幅因子异常变化与地震有较好的对应关系。由于潮汐分析方法本身的科学性和严密性，故振幅因子误差小、精度高；又因为对潮汐谐波波群的选择，避免了以太阳日为基础的周期性干扰，Ｍ２、Ｏ１波振幅因子的地震异常识别则简易可行，并且可信度高。云龙台的固体潮观测具有较强的地震监测能力。  相似文献   

The　Q　value　variations　in　the　preparing　pro－cess　of　rock　rupture     

王彬  许昭永  赵晋明  胡毅力 《地震学报(英文版)》1996,(4)

ＴｈｅＱｖａｌｕｅｖａｒｉａｔｉｏｎｓｉｎｔｈｅｐｒｅｐａｒｉｎｇｐｒｏ┐ｃｅｓｏｆｒｏｃｋｒｕｐｔｕｒｅＢＩＮＷＡＮＧ１）（王彬），ＺＨＡＯ－ＹＯＮＧＸＵ１）（许昭永），ＪＩＮ－ＭＩＮＧＺＨＡＯ１）（赵晋明）ＹＩ－ＬＩＨＵ２）（胡毅力）１）Ｓｅｉ...  相似文献   

Inversion of Q value structure beneath the Tibet Plateau     

Jian-Ping Wu  Rong-Sheng Zeng 《地震学报(英文版)》1996,9(2):271-278

A total of 11 earthquakes with 15 Rayleigh wave paths, recorded at 11 broadband digital PASSCAL seismometers installed in the Tibet Plateau by the Sino-U.S. joint research group, were used to determine the phase velocity and attenuation coefficient of surface waves in periods of 10–130 s. The average shear wave velocity and quality factor {ie271-1} structures in the crust and upper mantle were obtained in this region. The result shows the average {ie271-2} is low and there exists a high attenuation ({ie271-3}=93–141) layer in the crust. The depth range of the low {ie271-4} value layer (16–42 km) is consistent with the range of low velocity layer (21–51 km) in the crust. Below 63 km in the lower crust, {ie271-5} decreases with depth from 114 to 34 at depth of 180 km. The low shear wave velocity and low value of {ie271-6} at the same depth range in the crust indicate that the rocks in the range is probably melted or partially melted. According to the shear wave velocity structure, the average thickness of the crust is about 71 km and a clear velocity discontiniuty appears at the depth of 51 km. The low-velocity zone (4. 26 km/s) at depth of 96–180 km may be corresponding to the asthenosphere. Contribution No. 96A0047, Institute of Geophysics, SSB, China. This study was supported by the National Natural Science Foundation of China.  相似文献   

对称化测量高频电磁波测井的优化组合研究          下载免费PDF全文

冯庆国  刘曼芬  杨善德 《地球物理学报》1996,39(Z1):379-386

采用对称化测量可克服现有单发双收高频电磁波测井仪器（ＤＰＴ）由于收－发不对称结构导致的幅度比测井曲线严重失真的缺陷，提高ＤＰＴ的纵向分辨率．通过对二线非均质测井环境下ＤＰＴ响应的数值模拟，指出选用原频率较低、源距较长仪器的相位差测量与源频率较高、源距较短仪器的幅度比测量进行组合，可获得高品质的视介电常数和视电阻率曲线，显著提高ＤＰＴ的资料解释能力．这里源频率的恰当选择起着关键作用．  相似文献   

不同温压条件下弹性波在岩石中传播速度的实验研究   总被引：10，自引：0，他引：10       下载免费PDF全文

马瑞  卢民杰 《地震地质》1996,18(3):259-265

对以岩浆岩为主的岩石类型进行了不同温压条件下弹性波传播速度的实验研究，结果表明：（１）岩石的物质组成是决定弹性波传播速度的主要因素。以岩浆岩为例，由酸性到基性波速呈增加趋势；（２）岩石中弹性波的传播速度随环境条件改变而变化。一般说来，随温压条件的升高而升高  相似文献   

云南地壳生热率分布   总被引：1，自引：3，他引：1       下载免费PDF全文

周真恒  向才英 《地震地质》1996,18(4):443-452

研究地壳岩石放射性生热率的垂向分布，是研究深部热结构的基础。根据深部地震测深资料，利用地震波速与生热率之间的关系，估计了云南地壳生热率的垂向分布。全区上地壳生热率一般为０．８～２．１μＷ／ｍ３，中地壳为０．４～１．２μＷ／ｍ３，下地壳为０．１１～０．５５μＷ／ｍ３  相似文献   

The effect of local irregular topography on seismic ground motion     

刘晶波 《地震学报(英文版)》1996,9(2):309-315

Ｔｈｅｅｆｆｅｃｔｏｆｌｏｃａｌｉｒｒｅｇｕｌａｒｔｏｐｏｇｒａｐｈｙｏｎｓｅｉｓｍｉｃ　ｇｒｏｕｎｄ　ｍｏｔｉｏｎＪＩＧ－ｈｏＬＩＵ（刘晶波）（ＤｅｐａｒｔｍｅｎｔｏｆＣｉｖｉｌＥｎｇｉｎｅｅｒｉｎｇ，ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙＢｅｉｊｉ...  相似文献   

Effects　of　magnitude　accuracy　and　complete－ness　data　on　seismic　hazard　parameters     

邵辉成  谢家树  王平  王亚秀 《地震学报(英文版)》1996,9(4):635-644

Ｅｆｆｅｃｔｓｏｆｍａｇｎｉｔｕｄｅａｃｃｕｒａｃｙａｎｄｃｏｍｐｌｅｔｅ┐ｎｅｓｄａｔａｏｎｓｅｉｓｍｉｃｈａｚａｒｄｐａｒａｍｅｔｅｒｓＨＵＩ－ＣＨＥＮＧＳＨＡＯ（邵辉成），ＪＩＡ－ＳＨＵＸＩＥ（谢家树），ＰＩＮＧＷＡＮＧ（王平）ａｎｄＹＡ－Ｘ...  相似文献   

Harmonic wave propagation through viscoelastic heterogeneous media exhibiting mild stochasticity - I. Fundamental solutions     

G.D. Manolis  R.P. Shaw 《Soil Dynamics and Earthquake Engineering》1996,15(2):119

This work examines the propagation of time harmonic, horizontally polarized shear waves through a naturally occurring heterogeneous medium that exhibits viscous behaviour as well as random fluctuations of its elastic modulus about a mean value. As a first step, the governing equation, which is a heterogeneous Helmholtz equation, is solved using algebraic transformations and the relevant Green's function is obtained for two sets of boundary conditions, one corresponding to a finite depth layer and the other to an infinite layer. Viscous material behaviour is introduced by considering the depth-dependent elastic modulus to be a complex quantity. Subsequently, material stochasticity in the medium is handled through the perturbation approach by assuming that the elastic modulus has a small random fluctuation about its mean value. The final results are closed-form expressions for the mean value and covariance matrix of both the wave speed profile in the medium and the corresponding Green's function. In Part II, (Soil Dynam. Earth. Engng, 1996,15, 129-39), two examples concerning seismic wave propagation in soft topsoil and in sandstone serve to illustrate the methodology and comparisons are made with Monte Carlo simulations.  相似文献