共查询到19条相似文献,搜索用时 107 毫秒
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史红军 《地震地磁观测与研究》2012,33(Z1)
利用吉林省地电阻率台网观测资料,对汪清7.1级上深震以及乾安、前郭5.2级中强地震前地电阻率异常变化进行分析,发现吉林省地电阻率台网对本区内中等以上地震具有一定监测能力. 相似文献
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对新疆烈度速报台网子台的地脉动进行了测试分析,对照新疆烈度速报台网子台的钻孔资料、等效剪切波速并结合新疆的区域地质构造特征,得到新疆强震动烈度速报台网10个台站的场地类别。同时认为对个别判定指标临近划分标准分界线的台站的分类工作还需进一步研究。 相似文献
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基于地脉动噪声计算方法,以呼伦贝尔市地震台网8个台站连续波形资料为基础,对地震观测台网监测能力进行评估,同时开展台网优化和科学布局研究。通过累计的历史噪声数据,用来评估台站观测环境的变迁,及时掌握地震监测能力的变化。该成果将为地震速报、重点地震危险区震情跟踪、强震后现场应急提供科学参考。 相似文献
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对本台数字化地震观测以来记录到的典型地震,运用数字地震信号处理方法,测算每个抽选地震震前一分钟地脉动信号在时间域和频率域的特征数据,通过频谱分析法,获得了震前地脉动噪声频谱的差异性。初步研究了典型地震震前地脉动频谱变化的特征和规律,共归纳了18类震前地脉动噪声类型,按照无震平静分钟值脉动频谱特征类比典型地震震前分钟值频谱的异样变化,发现正常与异常的地脉动噪声特征,最主要的还是受震级强度和地理位置的影响较大。临震前地脉动分钟值频谱特征异常,可用于震前脉动前兆异常变化跟踪,从而利用地脉动频谱的特征参量监测地震孕育过程,为地震中长期及短临预报提供依据。 相似文献
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The characteristics of substorm-associated Pi2 pulsations observed by the SABRE coherent radar system during three separate case studies are presented. The SABRE field of view is well positioned to observe the differences between the auroral zone pulsation signature and that observed at mid-latitudes. During the first case study the SABRE field of view is initially in the eastward electrojet, equatorward and to the west of the substorm-enhanced electrojet current. As the interval progresses, the western, upward field-aligned current of the substorm current wedge moves westward across the longitudes of the radar field of view. The westward motion of the wedge is apparent in the spatial and temporal signatures of the associated Pi2 pulsation spectra and polarisation sense. During the second case study, the complex field-aligned and ionospheric currents associated with the pulsation generation region move equatorward into the SABRE field of view and then poleward out of it again after the third pulsation in the series. The spectral content of the four pulsations during the interval indicate different auroral zone and mid-latitude signatures. The final case study is from a period of low magnetic activity when SABRE observes a Pi2 pulsation signature from regions equatorward of the enhanced substorm currents. There is an apparent mode change between the signature observed by SABRE in the ionosphere and that on the ground by magnetometers at latitudes slightly equatorward of the radar field of view. The observations are discussed in terms of published theories of the generation mechanisms for this type of pulsation. Different signatures are observed by SABRE depending on the level of magnetic activity and the position of the SABRE field of view relative to the pulsation generation region. A twin source model for Pi2 pulsation generation provides the clearest explanation of the signatures observed. 相似文献
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蒋光亮 《地震地磁观测与研究》1996,17(5):50-55
一种新的临震异常-地倾斜以脉动群自1988年以来已出现31次,作出短临预报的有15次,显示出较大的临震预报作用,这种脉动群可能是孕震后地壳断裂加速活动时产生的一群压性和压扭性小裂隙的外在标志。 相似文献
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根据石家庄市区场地脉动和剪切波速的实例资料,分析了石家庄市区场地脉动的特征以及剪切波速,并给出了场地脉动周期与场地土怪固有周期的统计关系。认为该地区的脉动周期随覆盖层厚度及覆盖层层数的增大而减小,而剪切波速则随深度的增加而增大。 相似文献
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Karel Dobeš Karel Prikner Jaroslav Střeštík Reviewer M. Hvoždara 《Studia Geophysica et Geodaetica》1973,17(3):240-244
Summary A new method is presented of computer processing of amplitude-time records. The method is based on a two-component spectral analysis, suitable for investigating a planar stationary oscillatory event. The method is applied to the study of the fine structure of short-period geomagnetic pulsations. Apart from a semi-quantitative representation of the directional distribution of the pulsation event in the plane of oscillation, the proposed method enables one to obtain quantitative information on the frequency components, representing the pulsation — the distribution of the overall energy in the spectrum of the pulsation, the ellipticity of the polarization ellipses, the orientation of the major axes of the ellipses, and the sense of rotation of the disturbance vector. 相似文献
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本文利用低纬地磁台站的Pi1、Pi2地磁脉动(Pi1-2)资料和地球同步轨道的Pc5地磁脉动资料,对2004年1月到2006年12月38个磁暴事件的地磁脉动参数进行了统计分析.在此基础上,考虑相对论电子的局部加速机制,并加入损失机制,建立了一个初步的磁暴期间地球同步轨道相对论电子通量对数值的预报模型.利用该模型,我们对上述38个磁暴事件进行预报试验,最优化结果是:相对论电子通量对数值的预测值和观测值之间的线性相关系数为0.82,预报效率为0.67.这说明该模式具有较好的预报效果,也表明利用地磁脉动参数进行相对论电子通量预报是可行的. 相似文献
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