保山滇十四井模拟与数字化水位观测资料对比分析

通过对保山滇十四井水位观测点模拟与数字化并行观测资料的对比分析,说明该井的模拟与数字观测数据内在质量接近,数据相关性好,数据的变化形态及地震同震响应特征相似。数字化观测有干扰小、信息及时、仪器易维护的优点,认为该井数字化观测可以取代模拟观测。     

观测时间对地磁绝对观测值的空间相关性影响研究

应用FHD磁力仪的观测数据。对比了每日不同时间Z分量观测值组成的逐日变化序列的空间相关性,表明夜间观测数据的空间相关性低于白天,并分析了产生这一现象的原因。同时,通过对通化后的磁称Z分量不同观测时间的绝对值震磁相关异常分析,表明夜间观测数据更有利于提取空间相关异常。这对今后应用数字化地磁观测资料研究与地震有关的震磁相关异常有一定的指导意义。     

山西临汾中心地震台数字洞体摆观测资料映震能力分析

介绍了山西临汾中心地震台的台址条件及数字洞体摆观测资料的基本情况,对2008年至2010年6月间的观测资料与全球Ms〉7．0、中国境内Ms〉6．0以及山西省内Ms〉4．0地震之间的对应关系及异常图像进行分析。结果表明,数字洞体摆观测资料可靠稳定,震前有明显的异常显示,能记录到不同方位强震的震时脉冲信号,资料具有较强的映震能力。     

琼海加积井水位模拟观测与数字观测资料对比分析

通过对琼海加积井数字水位与模拟水位的观测资料进行对比分析,发现其动态变化特征一致,与固体潮的相关系数也基本一致,数据的相关性及内在质量良好,映震能力相当。数字观测具有数据信息量大,传输速度快,人为误差小的优点,可以取代模拟水位观测。     

汶川大地震四种仪器观测到的异常现象及相关问题讨论

本文介绍了中国地震局地壳应力研究所研制的数字倾斜仪、断层形变仪、分量式钻孔应变仪和地热仪在5.12汶川大地震前观测到的异常资料.这些仪器出现异常的时间和幅度不同.其中,位于震中区什邡的数字倾斜仪在震前15天出现突变异常,异常幅度达到2007年年变化幅度的3.7倍.位于南北带南段彝良的倾斜仪的观测数据在震前18～22天发...     

新04号井数字化水位观测与模拟观测资料的对比分析

在以往30多年曲地震地下流体水位观测中，我国地震地下流体分析预报人员积累了大量水位震例数据和不少宝贵经验，但这些震例和经验都是基于以往的模拟水位观测资料基础上的。如果观测方式进行了数字化改造，那么以往的震例经验还能否继续适用是一个值得探讨的问题。     

衡水冀16井水位观测数据质量分析

对2017—2019年衡水冀16井水位观测资料的完整率和稳定性、变化形态、观测精度、潮汐因子、中误差、同震效应等进行分析,结果表明：①衡水冀16井水位观测资料完整率较高,仪器工作稳定,符合地下水位观测规范要求;②固体潮效应显著,潮汐响应能力较强,潮汐因子平均值为2.1—2.2,观测精度均值为0.01左右,相对误差较小,且较稳定;③同震响应能力较强,能记录到全球7级以上地震,同震水震波波形清晰;④水位与气压变化之间相关性较好,整体呈负相关;⑤水位观测资料年、月、日变化规律清晰,有望在地震地球物理监测中发挥一定效能。     

地磁数字与模拟观测资料对比分析

“九五”地震前兆数字化台站改造后，数字化的地磁观测仪器在全国各地磁台站推广应用已有两年多时间，两年来，数字化观测仪器和模拟记录仪器在武汉台一直进行并行观测工作，其观测资料稳定可靠。本文通过GM-3磁通门磁力仪与其它仪器进行数字和模拟观测资料的时均值、日均值、月均值、年均值对比分析。分析结果表明数字观测资料优于模拟观测资料，数字观测仪器完全可以取代模拟观测仪器。     

云南部分水位观测点模拟与数字化并行观测资料对比分析

通过对云南4个水位观测点模拟与数字化并行观测资料的对比分析,认为同一个观测点的模拟与数字化观测数据内在质量接近、数据相关性好、数据的变化形态及地震同震响应特征相似,在这些并行观测的观测点上数字化观测可以取代模拟观测.     

盘锦地区水位观测与石油开采关系分析

经过多年水位观测,发现盘锦地区水位有时出现无震时“异常”变化.将辽河油田石油开采数据与本地区水位资料对比分析,结果表明:盘锦地区地下水位受油田开采影响,抽水、注水影响本区观测井水位趋势变化.为今后研究本区水位中、长趋势变化提供借鉴,为准确识别地震异常提供参考意见.     

黄河中游河流阶地的对比及阶地系列形成中构造作用的多层次性分析

黄河在流经青藏市原东北缘海原－同以弧形构造区的过程中,发育了多达10－21组的斯座和侵蚀型阶地,其最大拔河高度为40lm,最高阶地的发育年代为1．57MaBP。通过对该区米家山、车木峡和黑山峡河口3处黄河阶地以及我国北方大范围内河流阶地的对比分析发现,河流阶地系列形成中在构造作用上具有多层次性特征,即它包含了不同范围或规模和不同级次构造隆升作用所导致的阶地。研究区的黄河阶地系列可以划分为3个层次。其中,第一层次的阶地共有6级,为我国北方大范围内同期形成的阶地,它们代表1．6Ma以来青藏高原阶段性隆升的次数,其隆升幅度由西向东逐渐减小;第二层次的阶地共有5级,为海原－天景山构造区内同期发育的阶地,它们代表1．6Ma以来该构造区本身自隆升的次数和幅度;第三层次阶地为发育在米家山东坡的10级不同期阶地,它们代表1．6Ma以来海原构造山地独自的抬升的次数和幅度。阶地发育时间与黄土－古土壤序列的对比还表明,反映青藏高原大范围构造隆升的第一层次阶地与气候变化之间有很好的可对比性,其形成年代均与相应古土壤发育时间的间冰期对应,暗示导致河流下切的在范围构造抬升与强干冷期后同样可导致河流下切的气候暖湿期紧密相关,它们共同组成了构造－气候旋回。第二层次和第三层次阶地的形成时间与气候变化之间无统一特定的关系,显示它们的形成更主要的受控于天景山块体和海原构造带的隆升作用。因此,研究区的河流阶地主要可分为2种成因类型。一种是在大范围构造抬升和气候变化联合作用下形成的构造－气候旋回阶地,此类阶地分布范围广,具有区域间的可对比性;另一种是以局部构造抬升为主导因素形成的脉动式构造旋回阶地,此类阶地的分布受 控于活动构造带,在构造区带内自成体系,不具有区域间的可对比性。     

宁夏地区GPS监测网建设、近期地壳运动特征及应力场与地震活动关系初探

在阿拉善块体、鄂尔多斯块体和青藏块体交汇处的宁夏中部布设了GPS观测网,利用1996年以来的5期复测资料,分析了宁夏中部地区现今地壳运动状态,其结果为①宁夏中部地区在l996年12月至l999年5月间,有围绕鄂尔多斯西缘(P2测点)左旋运动的现象,银川盆地东侧的灵武断裂呈左旋逆走滑运动方式.该区主应力场方向为北北东-南南西(方位角为29.8°)方向,P2测站以南的中部地区向东位移,垂直形变量级明显大于水平形变量级,银川盆地及青藏块体呈上升状态,鄂尔多斯腹地的P1测站呈逐年下降趋势,在P3与P4测点间可能有一隐伏断裂存在.②在GPS测区附近中强地震前约1年,可观测到该区GPS测站的形变异常及主应力方向发生转变异常;测区附近中强地震前及周边地区强震前,该区GPS形变模拟矢量场能够预示未来地震的大体方位.这些结果可作为地震预测的特征值加以考虑.     

高速铁路路基动土压力测试信号的小波分析

阐述了小波分析的基本原理与方法,选用Daubechies小波对某高速铁路路基土压力的现场振动测试信号进行分析处理。由此对高速列车荷载作用下,路基动土压力产生的机理及其土压力的构成进行较深入的研究。     

Kinematic features of the seismogenic fault of the Tangshan earthquake and the recurrence period of large earthquakes

ＫｉｎｅｍａｔｉｃｆｅａｔｕｒｅｓｏｆｔｈｅｓｅｉｓｍｏｇｅｎｉｃｆａｕｌｔｏｆｔｈｅＴａｎｇｓｈａｎｅａｒｔｈｑｕａｋｅａｎｄｔｈｅｒｅｃｕｒｒｅｎｃｅｐｅｒｉｏｄｏｆｌａｒｇｅｅａｒｔｈｑｕａｋｅｓＪＩＥＬＩＵ１）（刘洁）ＨＵＩ－ＺＨＥＮＳＯＮ...     

Comparison of River Terraces in the Middle Reach Valleys of the Yellow River and Analysis on the Multi-Gradational Features of Tectonism in the Formation of Terrace Series

Where the Yellow River flows through the Haiyuan-Tongxin arc-form tectonic region on the northeastern side of the Qinghai-Xizang (Tibet) Plateau, as many as 10～21 basis and erosion terraces have been produced, among which the biggest altitude above river level is 401m and the formation age of the highest terrace is 1.57 Ma B.P. Based on comparative analysis of the Yellow River terraces located separately in the Mijiashan mountain, the Chemuxia gorge, the Heishanxia gorge and the other river terraces in the vast extent of the northern part of China, it has been found that the tectonic processes resulting in the formation of the terrace series is one of multi-gradational features, i.e., a terrace series can include the various terraces produced by tectonic uplifts of different scopes or scales and different ranks. The Yellow River terrace series in the study region can be divided into three grades. Among them, in the first grade there are 6 terraces which were formed separately at the same time in the vast extent of the northern part of China and represent the number and magnitude of uplift of the Qinghai-Xizang Plateau since 1.6 Ma B. P. ; in the second grade there are 5 terraces which were separately and simultaneously developed within the Haiyuan-Tianjingshan tectonic region and represent the number and magnitude of uplift of this tectonic region itself since 1.6Ma B. P.; in the third grade there are 10 terraces which developed on the eastern slope of the Mijiashan mountain and represent the number and amplitude of uplift of the Haiyuan tectonic belt itself since 1.6Ma B.P. Comparison of the terrace ages with loess-paleosoil sequence has also showed that the first grade terraces reflecting the vast scope uplifts of the Qinghai-Xizang Plateau are very comparable with climatic changes and their formation ages all correspond to the interglacial epochs during which paleosoils were formed. This implies that the vast extent tectonic uplifts resulting in river down-cutting are closely related to the warm-humid climatic periods which can also resnit in river downward erosion after strong dry and cold climatic periods, and they have jointly formed the tectonic-climatic cycles. There exists no unanimous and specific relationship between the formation ages of the second and third grade terraces and climatic changes and it is shown that the formation of those terraces was most mainly controlled by tectonic uplifts of the Tianjingshan block and the Haiyuan belt. The river terraces in the study region, therefore, may belong to 2 kinds of formation cause. One is a tectonic-climatic cyclical terrace produced jointly by vast extent tectonic uplifts and climatic changes, and the terraces of this kind are extensively distributed and can be well compared with each other among regions. Another is a pulse-tectonic cyclical terrace produced by local tectonic uplifts as dominant elements, and their distribution is restricted within an active belt and can not be compared with among regions.     

Application of the extreme value approaches to the apparent magnitude distribution of the earthquakes

The apparent magnitude of an earthquakey is defined as the observed magnitude value and differs from the true magnitudem because of the experimental noisen. Iff(m) is the density distribution of the magnitudem, and ifg(n) is the density distribution of the errorn, then the density distribution ofy is simply computed by convolvingf andg, i.e.h(y)=f*g.If the distinction betweeny andm is not realized, any statistical analysis based on the frequency-magnitude relation of the earthquake is bound to produce questionable results. In this paper we investigate the impact of the apparent magnitude idea on the statistical methods that study the earthquake distribution by taking into account only the largest (or extremal) earthquakes. We use two approaches: the Gumbel method based on Gumbel theory (Gumbel, 1958), and the Poisson method introduced byEpstein andLomnitz (1966). Both methods are concerned with the asymptotic properties of the magnitude distributions. Therefore, we study and compare the asymptotic behaviour of the distributionsh(y) andf(m) under suitable hypotheses on the nature of the experimental noise. We investigate in detail two dinstinct cases: first, the two-side limited symmetrical noise, i.e. the noise that is bound to assume values inside a limited region, and second, the normal noise, i.e. the noise that is distributed according to a normal symmetric distribution.We further show that disregarding the noise generally leads to biased results and that, in the framework of the apparent magnitude, the Poisson approach preserves its usefulness, while the Gumbel method gives rise to a curious paradox.     

鄂尔多斯盆地西缘构造带北段深部电性结构

在横跨鄂尔多斯盆地西缘构造带北段的查甘池—银川—五湖洞约200 km长的东西向剖面上,进行了67个测点的大地电磁探测.使用“远参考道”和Robust技术处理数据.分析了各测点视电阻率、阻抗相位、二维偏离度、电性主轴方位角、磁实感应矢量等参数,采用NLCG二维反演方法对TE和TM两种模式的数据进行了二维反演.得到的二维电性结构表明,沿剖面查汗断裂带、贺兰山东缘断裂带和黄河断裂带是明显较大型电性边界,为超壳断裂带,而三关口断裂带深部延深不大.沿剖面阿拉善地块、贺兰山褶皱带、银川断陷盆地和鄂尔多斯地块具有明显不同的深部电性结构特征.阿拉善地块内部除浅表电阻率较低外,以下到深度约50 km都表现为高电阻特性.贺兰山褶皱带电性结构复杂,电阻率高低相间.银川盆地具有上宽下窄最深达约8 km低阻层,具有断陷盆地特征.鄂尔多斯地块具有低-高-低的深部电性结构特征,成层性较明显.     

Experimental Research on the Low Frequency Wave That Radiates into the Air before the Failure of Rock

INTRODUCTIONThephenomenonof“quiescence”beforestrongearthquakeshaswidelybeenaccepted .However,isitreallyquietbeforeanearthquake ?Accordingtorecordsfromshortperiodseismographs,itis“quiet”beforeearthquake ,butaccordingtotherecordsofbroadbandseismograph ,thismaynotbetrue .Thekeytothismatterishowtogetreliableinformation .Earlyinthe 1 970’s,manyseismologiststhoughtthattheultra lowfrequencywaveformrecordedbybroadbandseismometersbeforeearthquakescamefromfore sliporslow extending (Rikitake ,…     

基于论文、作者特征分析《山西地震》的现状

为提高《山西地震》的稿件质量,明确目前办刊中存在的问题,文章对2008年至2017年刊物的载文量、基金论文比指标、论文分类以及近18年第一作者的情况进行统计分析,进一步了解作者群的特点,发现核心作者。通过分析,明确今后发展的改进方向。     

土的工程力学性质与其电阻率关系实验研究

建立岩土的工程力学性质与其地球物理参数的量化关系是实现工程物探资料量化解释的必然前提。本次工作在分析影响土的工程力学性质和电阻率的共同因素基础上，通过室内实验，研究了不同类型土的粒度成分、含水率、饱和度、密实度与其电阻率的关系，并在此基础上探讨了耗土的压缩系数、粘聚力、压缩模量与电阻率的关系，得出了一系列的关系曲线及一些拟合公式，并对这些公式的含义进行了解释。