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1.
在研究大地电磁响应函数频散关系的基础上,构制了一套滤波系数算法,以用于由一套视电阻率资料估算相应的阻抗相位.理论模型和实际大地电磁观测资料的数字试验表明,该法是行之有效的.由频散关系估算的相位值与观测的相位资料的比较,可用于检验观测资料是否满足频散关系.利用经频散关系校正的阻抗相位值,进行大地电磁阻抗的联合反演则可望获得更为可靠的结果.研究了观测频带相互衔接的电偶源频率电磁测深和大地电磁测深视电阻率的一维联合反演问题.对两个实测点两种电磁法的观测资料进行了联合反演试验,与钻井资料对比表明,所获得的电性分层参数是较为可信的.在补充了由频散关系获取的电偶源频率电磁相位资料后,对于两种电磁法的视电阻率————阻抗相位、阻抗实部视电阻率-阻抗虚部视电阻率进行了拟大地电磁反演,获得了相近的反演结果. 相似文献
2.
地电阻率变化与孕震过程研究 总被引：1，自引：0，他引：1
在分析唐山７．８级地震前后地电阻率异常变化特征的基础上，研究地电阻率异常量△ρ／ρ０与应变的关系，给出了地电阻率异常量△ρｓ／ρ０对应变ε的转换关系式；分析和研究地电阻率异常发展，演变特征与地震孕震，发生过程的联系及其前兆异常标志。 相似文献
3.
在地质情况复杂化以及地质勘探精细化的要求下,有必要开展张量CSAMT正反演研究.考虑到各向异性对正反演结果影响较大,本文开展基于主轴各向异性介质的张量CSAMT正演研究.根据含源的电场控制方程,引入主轴各向异性介质的张量电阻率,将电场总场分解为一次场和二次场,一次场由Key的算法得到,二次场利用有限差分法计算,即实现了主轴各向异性介质的张量CSAMT三维正演.通过与二维有限元算法结果比较来验证算法的正确性;通过设计几组主轴各向异性三维模型,分析卡尼亚电阻率和相位的响应特征.结果表明卡尼亚电阻率ρxy和ρyx分别对异常体X方向和Y方向的电阻率变化敏感,说明张量CSAMT方法对识别各向异性具有优势.本研究为开展任意各向异性介质的张量CSAMT正反演研究提供基础. 相似文献
4.
江苏南京台北南测道2013—2016年年初出现了与邻近的南京江宁台同步的地电阻率长趋势上升变化,2016年的年中出现了与江宁台和稍远距离的江苏高邮、新沂台同步的趋势下降变化。本文用年变形态、消除年变等数据处理方法并联系该区降雨量分析了南京台等地电阻率长程观测数据,基于视电阻率变化与地下介质内部骨架电阻率ρ°、裂隙水电阻率ρf、裂隙率ν之间的本构关系讨论了地电阻率趋势变化的原因,得到:该台南北向测道地电阻率趋势上升变化起因于台站及周边区域性地下介质的应力调整过程,动力来源可能是本区域地壳局部构造运动。 相似文献
5.
本文导出了在两层均匀水平介质中垂向全空间地电阻率观测的理论解析式;确定ρ_S是ρ_2/ρ_1Z/L、H/L的函数。并经计算给出了一组垂向全空间地电阻率观测的年变幅理论曲线。指出只要适当选择布极深度和电极距,即可把年变幅压低到2％以下。对实验观测资料分析表明,观测基本稳定,资料连续可靠,年变幅在2％以下,与理论计算基本相符。理论与实验证明:垂向全空间地电阻率观测是压低干扰,获得平稳ρ_S值的有效途径。 相似文献
6.
本实验是在室温条件下对兰州河口砂岩进行了单轴加载,在与加载方向平行、垂直和成45°角的方向上观测了电阻率的变化特征。主要的实验结果是: (1)垂直层理加载时电阻率ρ_(?)(平行于加载方向)和ρ_(?)(垂直于加载方向)的变化分为三个阶段:上升—平稳—下降。(2)平行层理加载时电阻率ρ_(?)和ρ的变化表现出明显的各向异性。不论平行或是垂直层理加栽,在与层理面45°角的方向上的电阻率变化均较小。本文还对上述结果进行了定性解释。由于这种砂岩的放大因子较小(10—10~2),所以不适宜做地电台址。 相似文献
7.
本文从岩石和矿物电阻率的一般规律出发,导出岩石和矿物电阻率相对变化与湿度的近似关系,并试图应用它来解释视电阻率脉冲现象和地震的关系,同时讨论了ρ_s脉冲作为临震突跳异常的可能性,并得到几次震例的证实,为利用视电阻率脉冲作临震预报提供了某些依据。 相似文献
8.
大地电磁测深中相位微分的研究 总被引：2，自引：0，他引：2
大地电磁测深研究中,长期以来使用视电阻率和相位作为解释参数,但视电阻率和相位均存在一定的局限性。本文从理论上研究了相位微分的性质,探讨了Bostick电阻率和Cagniard电阻率同相位微分之间的关系,通过实例说明了相位微分的使用方法。结果表明,一维和二维TM模式的相位微分是一个很好的参数,对H型模型和A型模型都能得到较准确的地质体参数。 相似文献
9.
1.前言在地震预报研究中,关于地球电阻率(地电阻率ρs)与地震关系的研究取得了较大进展。但是,作为一种预报地震的手段,如能得到反映同一本质的其他电性参数的支持,可以增强其预报地震的可靠性。作者认为,岩石的介电常数ε_r,可以用来预报地震,可以与ρs法 相似文献
10.
偶极电测深法预报地震的试验研究 总被引：2，自引：0，他引：2
本文依据现场仪器观测资料,总结了1982年以来,用偶极电测深法预报地震的试验研究,结果表明:震前测区内不同深度的岩石电阻率确有不同程度的异常反映,并具深部岩石电阻率异常幅度较其浅部岩石电阻率异常幅度大之特点,最大幅度可达24％。实验表明,利用偶极电测深法观测到的中等深度(2～6km)的电阻率(ρ_s)异常要比四极对称法测到的浅层(几百米)电阻率(ρ_s)异常幅度大。该深度与郭增建提出的地下前兆优显层的深度大体相等。 相似文献
11.
Calculation of the parameters of georesistivi－ty anisotropy and case history of earthquake precursors 总被引：4，自引：0，他引：4
Ｃａｌｃｕｌａｔｉｏｎｏｆｔｈｅｐａｒａｍｅｔｅｒｓｏｆｇｅｏｒｅｓｉｓｔｉｖｉ┐ｔｙａｎｉｓｏｔｒｏｐｙａｎｄｃａｓｅｈｉｓｔｏｒｙｏｆｅａｒｔｈｑｕａｋｅｐｒｅｃｕｒｓｏｒｓＦＵ－ＹＥＱＩＡＮ１）（钱复业），ＹＵ－ＬＩＮＺＨＡＯ１）（赵玉林）ａ... 相似文献
12.
Features and physical process of the dynamic evolution pattern of ground resistivity precursor front
ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｔｈｅ１９６０′ｓ,ｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｍｏｄｅｒｎｓｃｉｅｎｃｅａｎｄｔｅｃｈｎｏｌｏｇｙｈａｓｇｒａｄｕａｌｙｍａｄｅｉｔｐｏｓｉｂｌｅｔｏｐｒｅｄｉｃｔｅａｒｔｈｑｕａｋｅｓａｎｄｈａｓｐｒｏｍｏｔ... 相似文献
13.
本文根据Aki等人提出的尾波理论,导出了地方震尾波水平分量与垂直分量的持续时间比的具体表达式: τ_H/τ_V=I_H/I_V(Q_H/Q_V)~(1/4)·B_H/B_V。该式表明,τ_H/τ_V的变化主要反映了震源体一定范围内,由于介质的各向异性而引起的尾波在不同方向上的激发及衰减能力的差异。本文还讨论了地震前τ_H/τ_V短临异常的物理机制,认为异常的产生与孕震期间介质内裂隙的出现和闭合有关。1986年门源6.4级地震和1975年海城7.3级地震前,τ_H/τ_V都有不同程度的短期低值异常及临震高值突跳。门源地震前后门源台记录的直达S波的最大振幅比A_(mH)/A_(mv)也有与尾波持续时间比类似的异常。最后通过对一些震例的分析,初步得到震级与异常时间的关系为M=0.657lnT+3.44。 相似文献
14.
Ａｌｉｇｎｍｅｎｔｓｉｌｋｗｏｒｍｓａｓｓｅｉｓｍｉｃａｎｉｍａｌａｎｏｍａｌｏｕｓｂｅｈａｖｉｏｒ（ＳＡＡＢ）ａｎｄｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｍｏｄｅｌｏｆａｆａｕｌｔ：ａｔｈｅｏｒｙａｎｄｌａｂｏｒａｔｏｒｙｅｘｐｅｒｉｍｅｎｔＭＯＴＯ... 相似文献
15.
This paper aims to analyse the geoelectrical resistivityρ
s
data on the dipole electrode sounding, which were firstly accumulated from the earthquake prone region in China. The analyses
on the one order difference value of the geoelectrical resistivity indicated that, firstly, more than 4 percent of theρ
s
data reveals the precursors by 3 to 76 days ahead the earthquakes occurring, with the magnitude range of 4 ≤M ≤ 6. 4, in a region of 100 km around the station, and secondly, the results revealed that the seasonal variation ofρ
s
data were slight.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 211–219, 1992. 相似文献
16.
THE RELATIONSHIPS BETWEEN EFFICACY OF GEOELECTRICAL RESISTIVITY METHOD IN EARTHQUAKE PREDICTION AND SITE CONDITION 
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下载免费PDF全文 INTRODUCTION In the past two decades, field observation, laboratory experiments, and the theoretical studies in the study on earthquake prediction have been carried out in several countries, by using ρ_s method, and valuable results have been achieved. The first geoelectrical resistivity (ρ_s) observatory for earthquake forecasting established at 相似文献
17.
论确定地震震源深度的地震宏观方法及其解答 总被引：1，自引：0，他引：1
作者基于在近场震源不能视作点源的认识,分析导出了相当于线、面源幅射场的深度公式,进而对源的类型不予作假定,将源指标的几何扩散率n作为待定参数,导出了一个物理意义明确且普遍化的震源深度公式。该公式的诸种解法中,以计算方法较准确,精度高;作图求解有较直观的优点,但准确性差,精度低;图算法仅作为获取粗略值和考察数据的均匀性用。用该公式对我国发生的一些不同震级的地震的震源深度进行了计算,经对比,效果很好。利用计算所得震源类型,初步研究了这些地震的震源几何学,并且首次给出了宏观地震震源深度测定值的标准误差。 相似文献
18.
: The knowledge of the volume and duration of low-flow events in river channels is essential for water management and the
design of hydraulics structures. In this study, both preceding characteristics, X
1 and X
2, are considered simultaneously via two types of bivariate distributions whose marginals are exponential. One of these bivariate
distributions has been presented by Nagao and Kadoya (1971) and the other has been used by Singh and Singh (1991) to the study
of rainfall intensity and rainfall depth. The results are applied to the low-flow series (“peaks-below-threshold”) of Lepreau
River (station 01AQ001) in New Brunswick, Canada. These results show that the model that was successfully employed by Singh
and Singh (1991) to study rainfall, presents certain difficulties when a very strong correlation, ρ, between the two random
variables X
1 and X
2, exists. The model by Nagao and Kadoya (1971) seems to be more satisfactory for such situations, although this model seems
also to be quite sensitive to variations in ρ. 相似文献
19.
F. Ashkar N. El Jabi M. Issa 《Stochastic Environmental Research and Risk Assessment (SERRA)》1998,12(2):97-116
: The knowledge of the volume and duration of low-flow events in river channels is essential for water management and the
design of hydraulics structures. In this study, both preceding characteristics, X
1 and X
2, are considered simultaneously via two types of bivariate distributions whose marginals are exponential. One of these bivariate
distributions has been presented by Nagao and Kadoya (1971) and the other has been used by Singh and Singh (1991) to the study
of rainfall intensity and rainfall depth. The results are applied to the low-flow series (“peaks-below-threshold”) of Lepreau
River (station 01AQ001) in New Brunswick, Canada. These results show that the model that was successfully employed by Singh
and Singh (1991) to study rainfall, presents certain difficulties when a very strong correlation, ρ, between the two random
variables X
1 and X
2, exists. The model by Nagao and Kadoya (1971) seems to be more satisfactory for such situations, although this model seems
also to be quite sensitive to variations in ρ. 相似文献
20.
D. PATELLA 《Geophysical Prospecting》1973,21(2):315-329
In a previous paper it has been shown that we can relate the transient IP electric field Ep , existing in a rock after a step wave of polarizing current, with the steady-state current density Jss during the current step wave as follows: Ep =ρ' Jss . This relation may be interpreted as a generalized Ohm's law, valid in linear cases, in which ρ’(fictitious resistivity) is defined as the product of the true resistivity ρ with the chargeability m. Supposing E p=— grad Up and applying the divergence condition div Jss = o, one can, for a layered earth, obtain a general expression for the depolarization potential Up as a solution of Laplace's equation ?2Up= o. Since the mathematical procedure for the solution of this last equation is identical to that used in resistivity problems, we propose now the introduction of an apparent fictitious resistivity ρ'a (defined as the product of the apparent resistivity ρa with the apparent chargeability ma) as a new parameter for the interpretations of IP soundings carried out over layered structures with a common electrode array. The most general expression of ρ'a as a function of the electrode distance turns out to be mathematically identical to the general expression of ρ'a. Therefore it is possible to interpret a ρ'a field curve using the same standard graphs for resistivity prospecting with the usual method of complete curve matching. In this manner a great deal of work is saved since there is no need to construct proper ma graphs for the interpretation of IP soundings, as it has been done up to now. Finally some field examples are reported. 相似文献