Measurement of interstation phase velocity by wavelet transformation

In this paper,we present wavelet transformation method to measure interstation phase velocity. We use Morlet wavelet function as mother wavelet to filter two seismograms at various period of interest,and correlate the wavelet filtered seismograms to form cross-correlogram. If both wavelet filtered signals are in phase at that period,the phase of the cross-correlogram is a minimum. Using 3-spline interpolation to transform cross-correlation matrix to a phase velocity verse period image,it is convenient for u...     

Crustal structure in Xiaojiang fault zone and its vicinity

Based on the integrative interpretation of travel-time data and amplitude information obtained from the deep seismic sounding experiment on the Chuxiong-Luoping profile,eastern Yunnan province,carried out in January of 2005,we present a 2-D P wave velocity structure along the profile. The crustal structure shows remarkable contrasts between the two sides of the Xiaojiang fault zone,although the whole profile is situated within the Yangtze platform. The average P wave velocities of the crust on the west and ...     

Reaearch on Skempton’s coefficient B based on the observation of groundwater of Changping station

Based on isotropic linear poroelastic theory and under the undrained condition,we summarize three equations connecting the Skempton’s coefficient B with the groundwater level.After analysis,we propose a method to calculate the Skempton’s coefficient B according to the relationship between water level and tidal strain.With this method we can get the value of B without the earthquake occurrence,which can provide the high frequency waves for research.Besides,we can also get the in-suit Skempton’s coefficient B...     

A modified exponential model for reported death toll during earthquakes

Reliable earthquake death toll estimate can provide valuable references for disaster relief headquarters and civil administration departments to make arrangement and deployment plan during post-earthquake relief work, thus increasing the efficiency of the relief work to a certain extent.In this study, we acquired the death toll data of Wenchuan earth-quake, fitted the data using modified exponential curve and compared the result with that of the exponential function.Experimental verification with Chi-Chi ea...     

琼西北地区的基底速度图象

利用人工地震测深纵剖面和非纵剖面的资料,对琼西北地区P_g波的走时进行了层析反演,对比了代数重建法和同时迭代重建法的效果.综合了纵剖面的模型后,在三维弯曲界面上重建了基底速度图象,探讨了用射线椭圆评价分辨的途径. 层析成象结果给出了许多有价值的信息,揭示琼西北的结晶基底存在三条北东向断裂和两条北西向断裂,后者是继承性的活动断裂,控制着新生代次级断块的发展与火山活动.地表所推断的东西向王五-文教深大断裂,在该处只呈断续隐伏状显示.该区的基底存在儋县、临高和光村三个高速区,主要反映着基性岩体或花岗侵入体.基底整体性最好的是在儋县-王五地区,破碎程度最严重的是在王五-中和-光村以西的地区.     

煤体性质对煤吸附容量的控制作用探讨

煤体性质是影响煤吸附容量的重要因素之一。通过对中国华北和西北两个重要煤层气富集区煤的煤岩学、煤化学和等温吸附实验分析,从煤级、显微组分、煤体变形三个方面对煤的吸附容量及其控制因素进行了, 分析探讨。结果表明,水分平衡条件下煤的吸附容量与煤阶的关系为倒U字型,吸附容量随煤阶的变化为跃变式, 基本与四次煤化作用跃变阶段相对应,主要受控于煤化作用过程中煤的亲甲烷能力和孔隙度的变化;煤体中惰质组含量较高时,其对煤体的吸附容量的影响较为明显,主要与惰质组中丝质体的高吸附能力有关;在构造应力作用下,煤体表面物化发生的变化使构造煤吸附容量比同一矿区同一煤层原生结构煤高。     

地球化学信息在湖南国民经济和社会发展中的作用

利用湖南省丰富的地球化学基础资料,阐述了其在湖南高科技农业,环境评价,资源开发等方面的作用,并指出了大力开发地球化学信息的意义     

辽宁阜新地区晚太古宙花岗质岩石在中地壳糜棱岩化过程中的体积亏损和成分变异

对辽西阜新地区晚太古宙韧性剪切变形变质岩石岩石学,常量、微量和稀土元素地球化学和矿物学的研究表明,在中地壳环境下的韧性剪切变形变质进程中,岩石中的元素都发生了不同程度的变异,主要表现为随变形强度的增加ＳｉＯ２,Ｎａ２Ｏ,Ｚｒ等组分规律性减少,而Ａｌ２Ｏ３,ＣａＯ,ＦｅＯ,ＭｇＯ等常量元素、稀土元素以及Ｂａ,Ｃｒ,Ｓｒ,Ｎｉ,Ｒｂ等微量元素规律性增加,本文认为剪切变形变质岩石的成分变异不仅仅是流体作用的结果,而且与剪切变形变质过程中的体积亏损相关。     

The Crust-Mantle Structure in Zhangbei-Shangyi Earthquake Area

The seismic data obtained from the wide angle reflection and refraction profiles that pass through Zhangjiakou area of Hebei Province were interpreted. Some conclusions drawn from the result are as follows: (1) The nearly EW-trending Zhangbei-Chongli crustal fault zone and WNW-trending Zhangjiakou-Bohai Sea deep crustal fault zone meet in the Zhangbei earthquake (Ms = 6.2) area; (2) At the intersection, the two deep crustal fault zones that stretch to the Moho and the discontinuities of interfaces within the crust form the path for large area basalt eruption in Hannuoba; (3) In the earthquake area, the local velocity reversal in the middle-upper crust and abnormal low velocity zone in the lower crust imply that the magmatic activity there is still fairly violent; and (4) The recent activity of Zhangjiakou-Bohai Sea deep crustal fault zone may be the main cause of the Zhangbei earthquake.     

上地幔各向异性分析中地壳的影响

应用伪谱法研究了地壳各向异性对上地幔各向异性分析的影响. 用几种不同情况下的两层各向异性模型,模拟了全波场,着重分析了不同深度观测点上的剪切波分裂特征. 结果表明,当地壳为各向同性或其各向异性主轴与上地幔重合或相互垂直时,在地壳观测到的快、慢剪切波的偏振方向保持了上地幔中的偏振方向;重合时,快、慢波走时延迟增大;垂直时,走时延迟减小. 当地壳的各向异性主轴与上地幔成一般夹角时,其粒子运动轨迹变得十分复杂,不能直观地识别上地幔各向异性中的快波方向,对走时延迟也有一定的影响. 将常用的两种分析方法应用于对模拟结果的反演,发现当地壳各向异性与上地幔各向异性方向为一般夹角时,反演结果会出现较大的误差或误判. 进而提出解决这一问题的方法,一是综合多种方法的结果;二是由拟合残差或相关系数等值线作进一步的确定.