共查询到19条相似文献，搜索用时 15 毫秒
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高压直流输电故障、地电暴、地电阻率观测人工供电、地铁等通常会对地电场观测带来较大干扰,对观测资料的应用、地震异常信息的提取识别等带来了很大困扰。选取陵阳、瓜州等13个观测系统较好的地电场台站,基于大地电场岩体裂隙水(电荷)渗流(移动)模型,计算实际观测中这些典型干扰下各场地大地电场优势方位角α的变化情况。结果表明：通常的地电暴、高压直流输电、地电阻率观测人工供电、城市轨道交通等干扰,计算的α值受影响不明显,但持续多日的大幅度、剧烈干扰可能导致部分场地出现影响。通过对2018年9月陕西宁强MS5.3震例分析,其结果表明复杂环境中周边场地强震前的α值异常可能也显著。研究结果对地电场数据应用可能有一定参考意义。 相似文献
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系统整理分析了2007年6月1日以来的陇南地电场观测资料,对一些影响地电场数据变化的干扰因素进行识别与分析,认为这些干扰主要为地电暴、地电阻率供电、降雨、农田灌溉和雷电干扰等。对观测数据的日变形态和特征进行总结,认为干扰的表现形式主要为台阶型、方波型和阶跃型以及高频脉冲和不规则大幅度突跳等。正确识别和排除各类干扰,并正确处理观测资料,对进一步提高观测资料质量及应用具有重要的意义。 相似文献
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应用基于EMD的小波阈值去噪方法,去除地电场观测资料中轨道交通干扰,并将小波阈值去噪法和EMD去噪法的效果相比较,结果表明:该方法能够滤除地电场信号中的地铁干扰,同时保留原始信号中微小的突变,突出有用信息,提高地电场台站观测数据的使用率,有较好的去噪效果。基于EMD的小波阈值去噪方法可推广到其他地球物理观测资料的去噪分析,甚至地电场与地电阻率同场地观测中人工供电干扰信号的剔除。 相似文献
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地电场观测过程中的干扰因素分析 总被引：3，自引：1，他引：2
本文主要利用榆树地震台2000年以来的地电场资料,对观测中常见的干扰因素进行了详细的识别与归类。研究结果表明：在地电场观测过程中存在地电阻率同场观测干扰、雷电干扰、地电暴干扰、电极长期稳定性问题引起的数据漂移及数据传输错误等。 相似文献
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随着人类的活动,地电阻率和地电场观测受到更多干扰。介绍浙江省长兴深井地电台建设过程,并讨论建设中存在的问题,初步分析地电观测资料,证明井下地电阻率和地电场观测在一定程度上可以屏蔽干扰,由此可见建设深井地电台的重要性。 相似文献
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针对我国地震监测预报中地电阻率定点连续观测中存在的偶极接地线的干扰问题, 本文将台站区域地层简化为3层均匀介质模型, 将接地线等效为偶极接地的电阻体, 建立了接地线干扰地电阻率观测的耦合物理模型. 通过有限元分析软件ANSYS模拟分析不同电性断面情况下接地线对地电阻率观测的影响, 同时分析这种干扰的产生机理, 并结合实际观测中存在的干扰问题作了对比验证分析. 结果表明: ① 接地线使得供电电极产生的地下对称性电场分布发生局部调整, 从而影响地电阻率观测; ② 接地线对地电阻率观测的影响主要取决于线缆的位置及方位角的大小; ③ 适当增大电极埋深可以减小其对地电阻率观测的影响; ④ 电性结构的差异性决定干扰变化幅度的大小. 本文结果对相关台站地电阻率观测异常分析落实及干扰源避让和观测系统改造具有参考意义. 相似文献
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地电阻率交流观测方法能够有效抑制测区杂散电流的干扰,包括地铁、轻轨等城市轨道交通的干扰,但是由供电线路与测量线路间磁场的相互作用所引起的电感性耦合效应会对观测结果产生一定的影响.为研究电感性耦合效应的特征,本文建立了地电阻率交流观测的电感性耦合模型,同时计算了供电线路与测量线路间的互感系数.在此基础上,通过正演模拟分析供电信号频率、地电阻率值、供电线和测量线间距离以及平行长度等参数对电感性耦合效应的影响,并将电感性耦合模型应用于台站实际观测数据的分析中,验证模型的合理性.结果表明,电感性耦合效应随供电信号频率、供电线与测量线平行长度的增大而增大,随供电线与测量线间距离的增大而减小,随地电阻率的变化存在峰值;且模型预测的地电阻率值与台站实际观测值有较好的一致性.本文的研究结果为消除地电阻率交流观测值中的电感性耦合效应提供了理论依据和基本模型,为地电阻率交流观测系统的设计和建设提供参考. 相似文献
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地磁扰动事件的描述及处理 总被引：1，自引：1，他引：0
影响地磁观测的因素很多,只有充分了解干扰的机制,才能对其数据进一步的处理。而在GM3,GM4提供秒采样数据后,观测数据中干扰数据的形态就可以非常清晰。本文就是利用秒采样的数据对几种常见干扰情况进行了描述,并使用软件对干扰数据进行剔除。 相似文献
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地电场是联系空间Sq电流体系、 地球表面电流和内部电流活动的地球物理量, 它包含了空间电流系变化产生的大地电(流)场和区域环境变化等引起的自然电场。 通过研究青藏高原东北缘的天祝台阵5个固定地电场台站连续10年观测数据, 得出该区域地电场变化具有明显的366±(<1) d周期。 且大地电流矢量方向有明显的季节变化, 每半年改变一次方向, 方向变化时间一般为每年4月和9~10月; 大地电流矢量的强度变化也具有周期性。 通过建立简单模型进行定量化分析, 认为地电场季节变化主要受到Sq年变和区域气候环境的耦合作用, 主要依据为地电场长趋势变化与电离层Sq电流年变化趋势吻合。 基于区域性气候、 冻融深度等季节性变化模型开展计算, 认为气温导致了地下浅层介质电性结构、 电极附近电位方向的变化, 影响了地电场的长趋势变化。 本文结果有助于认识超低频地电场年变周期特点及其原因, 并探索其应用前景。 相似文献
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IntroductionThe telluric field observation and study in ewthquake prediction are re-developed since lastdecade mainly due to following three reasons: @ Greek scientists claimed they have predictedvarious earthquakes with high successful rate by VAN approach in their ten years of observationsand researches, which has attracted attentions from various aspects in the world; @ The debate onVAN (Ruan, 1998; Uyeda, 1995) approach arid mechanism pllts forward many urgellt researchprojects which in… 相似文献
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R. K. FR
HLICH 《Geophysical Prospecting》1971,19(1):118-132
Simultaneous observations of electrical earth-potentials along parallel measuring lines offer a simple but useful method to study telluric and stray-current potentials. Different correlation-factors between the records of both observation points can help to separate telluric from industrial stray-current potentials. A method is suggested to eliminate disturbing impulses of stray currents from continuous telluric current recordings as those made at observatories. The influence of stray currents can also be eliminated from potential readings of an artificial current as applied in geoelectric measurements with the four-point-method. The elimination is possible by a simultaneous observation of the stray-current potentials on an equipotential line of the artificially generated field. The recording examples show an appreciable improvement of the signal-noise ratio without increase in the current. The method is useful for geoelectrical prospecting in areas which are contaminated by industrial noise. 相似文献
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K. K. Roy 《Pure and Applied Geophysics》1973,102(1):105-119
Summary The rotating nature of telluric field is simulated in an electrolytic model tank. Variations of this rotating field due to the presence of a few two and three dimensional geological models, simulated in the tank, are studied. The telluric ellipses, recorded on a C.R.O. Screen, are found to be useful for qualitative and quantitative interpretation of the non-linearly polarised telluric field data. Relative usefulnesses of the various parameters, e.g., (i)M=ratio of the semimajor and semiminor axis, (ii)K = square root of normalized surface areas, (iii) = linear eccentricity ((a
2/b
2-1) and (iv)e = conventional eccentricity ((1-b
2/a
2)), of a telluric ellipse are tested. Linear eccentricity appears to be the most sensitive parameter. Methods for determining depth and horizontal extent of a structure from a telluric map are suggested. Near surface inhomogeneities, as revealed from the experiment are unlikely to affect the telluric map due to a basement structure. 相似文献
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地磁秒采样仪器观测过程中,易受各种环境干扰造成数据异常,如磁暴、高压直流输电、人为干扰、仪器故障等,不易被发现并识别,若不能及时处理,将会造成观测数据质量下降。若诸多干扰与磁扰叠加,将更不易识别,导致数据的错误处理。为了提高观测质量,利用现有编程技术,开发地磁秒采样数据智能分析系统软件,实现对地磁观测仪器工作状态、各种干扰、磁暴等现象的实时监控和分析,及时发现异常并报警,同时利用多台数据对比智能分析软件,对复杂干扰和高压直流输电干扰进行自动识别,并数据曲线中标示干扰位置,提高数据资料处理的准确性和有效性。 相似文献
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宁波ZK03井动水位观测中的干扰异常现象分析 总被引：2，自引：0，他引：2
通过对宁波地震台ZK03井动水位9年多的观测资料分析,发现该井动水位观测中主要存在3个方面非人为因素干扰引起的异常现象.①强降雨干扰引起的异常,特征为测值阶跃式上升,但变化幅度不大,易识别;②气压突变引起的干扰,为测值脉冲式向上突跳,但不多见;③公用数采接触不良干扰,引起的是整点测值大幅度上下振荡,结果造成观测数据无效... 相似文献
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DIFFERENTIATION DIRECTION OF TELLURIC CURRENTS IN THE SOUTHERN SECTION OF THE TANLU FAULT ZONE 
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下载免费PDF全文 The Tancheng-Lujiang Fault is an important tectonic boundary in eastern China. The southern part of the Tancheng-Lujiang Fault is located south of Baohai Bay, which is an area with a dense population and frequent economic activities. It is worth conducting an in-depth study on the southern section of the fault, especially in the aspect of geophysical exploration and seismicity analysis. Electrical structure detection is an important way to interpret the structural activity of the fault. It can also analyze and explore the influence of the fault on the physical properties of both sides of the fault based on the geoelectrical observation data. In the study area, there are densely distributed stations of geoelectrical observation, including 27 fixed stations distributed along the fault zone from the southern Baohai Bay to Nanjing, Jinagsu Province. The continuous observations and recording of these stations provide a favorable condition for studying the tectonic activity of Tancheng-Lujiang Fault.
In the long-term observation of geoelectric observation network, the geoelectric field measurements of long- and short-spacing measuring tracks in the same direction at the same station vary significantly because of the effect of long-term stability of the observation system and the environment near the electrodes. Also, the data curve changes complicatedly and seems to be in a mess. However, there are three basic facts of observation existing in the geoelectric field change: 1)The variation amplitude of the geoelectric field changes observed on the long- and short-spacing measuring tracks in the same direction at the same station(including tidal response changes and the rapid change events such as short periods or pulses)is the same or very close; 2)The Ex and Ey components at the same station always show the same variation in the same time period, or the opposite, which is related to the anisotropy of the medium under the station; 3)The rapid changes of the minute values of the geoelectric field observed at different stations are synchronous in a wide spatial area. In this study, in order to take full advantage of these basic facts, we only use the amplitude variation of geoelectric field with time.
Based on the data of 27 geoelectric field observation stations in the study area, we used the current density vector and streamline to characterize telluric current with its divergence and vorticity calculated in the southern Tancheng-Lujiang Fault in this paper. The results show that: 1)the telluric current shows the phenomenon of opposite directional differentiation in the southern part of the fault zone, the direction of the current vector is NE on the east side, while the direction is NW to SW on the west side; (2)The divergence and vorticity of telluric current also show the differentiation phenomenon along the fault, the positive/negative maximum of vorticity and divergence mainly occurs near the fault zone and the direction of alternating positive and negative gradient(or negative gradient)of vorticity or divergence is consistent with the strike of the fault zone. By analyzing the current superposition simulation results and comparing them with previous studies, an interpretation model of the above phenomenon is established in this paper. The results agree with previous studies on the electrical structure of this region. Besides, the results that telluric current differentiates along the fault zone may improve our understanding of the process of deep electrical and material migration. 相似文献