The Statistical Analysis of Migration of Strong Earthquakes-Taking the North China Region as an Example     

Qin Chengzhi 《中国地震研究》2004,18(2):178-187

The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration of strong earthquakes has mostly focused on finding the phenomena. Some attempts on getting regularity were comparatively subjective. This paper suggests that there should be indices of migration in earthquake dataset and the indexes should have statistical meaning if there is regularity in the migration of strong earthquakes. In this study, three derivative attributes of migration, i.e., migration orientation, migration distance and migration time interval, were statistically analyzed. Results in the North China region show that the migration of strong earthquakes has statistical meaning. There is a dominant migration orientation (W by S to E by N), a dominant distance (≤100km and on the confines of 300～700km), and a dominant time interval (≤1a and on the confines of 3～4a). The results also show that the migration will differ slightly with different magnitude range or earthquake activity phase.  相似文献   

A direction-dependent shear strength criterion for rock joints with two new roughness parameters     

Liren Ban  Chengzhi Qi  Chunsheng Lu 《Arabian Journal of Geosciences》2018,11(16):466

The surface morphology of a rock joint is closely related to its mechanical properties. To reasonably characterize a rock surface, two new roughness parameters were proposed in this paper. One is related to the average slope angle of asperities that contribute to the shear strength, and the other reflects the frictional behavior of asperities that is defined as the maximum possible contact area in the shear direction. Taking the standard joint roughness coefficient profiles as example, these two roughness parameters can be applied to describe the directional characteristics of shear strength. Based on their relationships with initial dilation angles, the proposed roughness parameters were incorporated into a peak shear strength criterion. It is shown that the predicted peak shear strength is consistent with experimental data, and there is a power–law relationship. The application range of new roughness parameters was determined, which may facilitate a measurement process.  相似文献   

The statistical structure of Lorenz strange attractors   总被引：2，自引：0，他引：2  

Zou Chengzhi  Zhou Xiuji  Yang Peicai 《大气科学进展》1985,2(2):215-224

The statistical characteristic quantities and marginal probability distribution of the Lorenz strange attractors were computed numerically. The results indicate that after a sufficiently long time the statistical characteristic quantities and marginal probability distribution tend to stable states, and the motion on the strange attractor is ergodic.  相似文献   

THE EFFECT OF ASPECT RATIO ON THE BIFURCATION PROPERTIES OF A DOUBLE PARALLEL-CONNECTION LORENZ SYSTEM     

Zou Chengzhi  Yang Peicai  Zhou Xiuji 《大气科学进展》1986,3(4):406-423

A double parallel-connection (DPC) Lorenz system is developed by performing spectrum truncation of the Galerkin series expansion of the two-dimensional Rayleigh-Benard convection equation. Analyses of the equilibrium states indicate that a convective roll stems from a flow with a given wavenumber first losing its stability for a particular aspect ratio β after a stable laminar flow gets unstable; when β has the value βc able to deprive synchronously two flows with different wavenumbers of stability, occurrences of convective rolls with different wavenumbers depend entirely on the initial conditions, in good agreement with the relevant experimental results. The calculations of the unstablized rolls show that, with a smaller β (as compared with βc), the DPC Lorenz system has the same bifurcation properties as the ordinary Lorenz system; for a moderate β, the system has very complicated periodic, quasi-periodic and phase-locking motions; for a larger β, it results in intermittent chaos and causes mean flows with different numbers of vortices to occur alternately with time. All these indicate that β has substantial effect on the two Lorenz systems coupled through parallel connection in their interaction and the results.  相似文献   

赴英、法交流访问的情况报告          下载免费PDF全文

赵成志  陈开喜 《气象科学》2002,22(3):372-378

本文是对欧洲中期数值预报中心（ECMWF）的考察，访问和交流的情况报告，较为详尽地介绍了ECMWF的机构，业务及研究的历史发展情况，同时，结合对法国奥里机场气象台的考察简要介绍了法国气象机构和业务建设以及英法两国气象教育与人才培养的基本情况。  相似文献   

金沙江水电开发区域工程地质环境综合评价   总被引：4，自引：0，他引：4  

李国和  王思敬等 《地球科学》2001,26(3):309-313

金沙江所流经的川滇交界地区是中国西南典型的活动构造区，区内地震及地质灾害十分严重，所以在金沙江水电梯级规划中，进行该区域的工程地质环境系统评价尤为重要，本文选取对工程地质环境有较大影响的九种因素，从地壳稳定性、地面稳定性、岩土稳定性三方面建立层次分析模型。根据层次分析所取得的因素权重值，按好、较好、一般、较差、差5个等级进行工程地质环境质量综合评价及分工。工程地质环境特征的分区性向我们显示各梯级工程规划选址区所存在的重大工程地质问题。  相似文献   

湖州台的近震监测能力   总被引：1，自引：0，他引：1  

吴承志 《地震地磁观测与研究》1992,13(4):14-19

本文根据湖州地震台DD-1地震仪记录的1980—1990年期间Δ<500km的近震资料和仪器放大倍率,利用理论计算Δ—Mmin曲线,b值检验3种方法,对湖州台的近震监测能力进行了估算和评价,得出了该台对目标监测区域内的有效监测震级。最后对区域地震台站的近震监测能力进行了讨论。  相似文献   

EGM96/2008重力场模型在似大地水准面构建中的应用     

王鸣鹤  孙成志  许丹萍  吴晓倩 《北京测绘》2020,(5):687-690

似大地水准面的构建可以将GPS测量的高程迅速转化为正常高,极大降低高程测量的成本,提高相关工作效率。将EGM96/2008重力场模型与“移去-恢复”法相结合,在矿区内建立似大地水准面,并使用不同的插值方法,验证最优方案。结果表明,使用二次线性插值的EGM2008重力场模型拟合效果更好,模型外符合精度达到3.6 mm,更适合应用于该区域似大地水准面构建。  相似文献   

在Zebiak-Cane模式中观测MJO强迫对ENSO可预报性的影响, 第1部分:对最大预报误差的影响     

PENG Yuehu  SONG Junqiang  XIANG Jie  SUN Chengzhi 《海洋学报(英文版)》2015,34(5):39-45

With the observational wind data and the Zebiak-Cane model, the impact of Madden-Julian Oscillation (MJO) as external forcing on El Ni(n)o–Southern Oscillation (ENSO) predictability is studied. The obs...  相似文献   

近58a南岳高山站气候变化特征分析     

潘筱龙  叶成志  张剑明  陈德桥 《南京气象学院学报》2015,7(1):68-78

采用1953—2010年南岳高山站逐日气象资料,运用线性回归、突变分析和小波分析方法,对该站平均风速、气温和降水的气候变化特征进行了分析,并对与平均风速变化密切相关的气温和降水进行了年际变化特征比较.结果表明:1)年和四季平均风速均呈明显减小趋势,在20世纪90年代前后风速有由大到小的突变,年平均风速存在显著的准2 a和准4 a周期;2)年平均气温、最低气温、最高气温均呈明显升高趋势,气温存在显著的准2 a和准4 a周期,且于20世纪90年代中期前后气温有由偏低向偏高的突变;3)年降水量呈下降趋势,存在显著的准2 a和准3 a周期;4)风速与平均气温、最高气温和最低气温呈负相关关系,均通过0.01显著性检验,风速与降水的相关性没有通过显著性检验,但风速与降水的变化趋势在20世纪60年代中后期、70年代中期到21世纪初有较好的反相位变化.  相似文献