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1.
本文尝试采用一种类似于加卸载响应比的简单算法将GPS观测应用于地震中短期预测.算法根据孕震区域在不同阶段的加卸载响应比变化判断未来地震的发生趋势:当地壳处于稳定状态时,得到的时间序列在1.0附近波动;而在临近地震之前会出现明显的异常高值.以2004年美国南加州的Parkfield地震为例对方法的有效性进行了研究,发现在地震发生前半年左右震中附近GPS台站得到加卸载响应比时间序列都发生了比较明显的异常变化;而一些距离震中较远台站却没有观察到类似的异常变化.这可能反映了孕震区地壳介质稳定性的变化,表明通过处理GPS观测资料可能获得新的地震前兆异常. 相似文献
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电离层foF2变化对地震反应非常敏感,与地震有关的电离层扰动变化结果似乎非常有望用于地震短期预测。格林威治时间2011年1月18日20:23分,一次7.2级的大地震发生在巴基斯坦的达尔巴丁(28.73oＮ, 63.92oＥ）。本文研究中,我们必须利用架设在巴基斯坦的伊斯兰堡（33.78oN, 73.06oE）、玛尔坦（32.26oN,71.51oE）和卡拉奇（24.89oN,67.02oE）三个垂直探测台站获得的白天（08:00 a.m. - 05:00 p.m.）小时值数据找出地震前的foF2异常变化特征。结果显示,在达尔巴丁地震前几天,foF2出现了显著变化;并且距离震中最近的台站观测到的频率与幅度异常变化大于较远的位于孕震区边缘的台站。尽管地震异常特征显著,但增加其它电离层参数可以提高foF2异常的高置信度水平。 相似文献
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提取了汶川地震前后成都台、木里台和西昌台地磁观测的Z分量数据,分3个时段对采样率为每秒一个点的观测数据每小时计算一个最大谱质心、平均谱质心和谱质心标准差。不同台站和不同时段谱质心的结果比较表明,三个参数在汶川地震前这一时段,成都台地磁Z分量显示较大的变化幅度,并存在震前逐渐升高的变化趋势,而其它台站和其它时段没有显示如此明显的特征。对比分析表明,成都台地磁Z分量显示出的谱质心变化是一个与汶川地震有关联的特征信息,且这一特征的出现与台站和震中的距离有关。对这一问题的深入研究,对于研究震磁关系、大地震的孕震机理,大地震的预测及大震发生位置的推测具有积极意义。 相似文献
4.
在临近大地震前,震源过程和前兆现象存在着一定的时间关系。本文从组合模式出发,利用断裂力学的应力一化学腐蚀理论来讨论临近大震前的震源过程和外因时震源过程的调制作用。在诸外因当中,为了研究宇宙线对地震的影响,本文具体分析了1965-1979年宇宙线μ介子强度变化的功率谱,首次得到了在所有周期分量中,准九天周期占有优势的结果。最后列举了宇宙线调制地震前兆的几个实例,并讨论了宇宙线对地壳中不稳定物质如过热液体暴沸的触发作用。 相似文献
5.
选取恩施台、涪陵江东台、石柱黄水台以及武隆仙女山台2012年1月至2017年11月地磁数据进行异常分析,得到各个台站的地磁谐波振幅比和加卸载响应比计算结果,并结合2017年11月23日重庆武隆M5.0地震震中附近地质构造背景分析地震前后地磁异常现象。分析结果认为大部分地磁谐波振幅比变化特征类似于地电阻率的变化特征,表现为"下降-转折-上升"过程。本次地震大致发生在转折上升的初期阶段,其中震中距较小的台站地磁谐波振幅比变化趋势不同步,但变化幅度大致相同,而震中距较大的台站地磁谐波振幅比变化趋势较为同步,变化幅度较大。此外,研究还表明震前地磁加卸载响应比异常高值在时空分布上与震中位置具有很好的对应关系。 相似文献
6.
概论 在探讨外因对地震的调制和触发作用时,以往人们曾作了许多研究工作。如寻找固体潮、气象条件、磁暴等各种外因与地震发生的相关性,讨论其中的物理机制等。本文则试图对宇宙线这一外因的强度变化与大地震之间的关系作一探讨。 相似文献
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本文介绍了宇宙线空间物理学在我国的形成和主要研究内容,包括:(1)空间探测,有火箭探测、卫星探测;地面宇宙线台站观测;宇宙线的水下测量;(2)宇宙线空间物理学研究,有宇宙线的日地传输;宇宙线强度变化与CME事件;宇宙线的源物质与加速过程;宇宙线的地球物理效应.最后提到宇宙线与人体健康,特别是流行性感冒、大的太阳质子事件与地震现象、太阳宇宙线事件与天气和气候等的统计研究. 相似文献
10.
基于中国大陆西部地区(108°E以西)地磁台站数据, 利用平滑伪魏格纳-维勒(SPWVD)分析方法, 对其进行时频计算。 通过对2007年至2015年间的MS6.3以上强震(选取岷县地震、 芦山地震、 鲁甸地震3个典型震例)周围台站地磁Z分量滤波后周期为4.4 h的振幅变化进行分析, 得到如下结论: ① 在3个强震发生前, 周围台站的Z分量4.4 h振幅在1个月内都出现了多台同步高值异常; ② 岷县地震、 芦山地震发生前1个月内高值异常的频次明显增多, 频次高出全年平均水平2倍以上; ③ 3个强震发生前1个月内, 台站时频异常幅度明显增大, 幅值达到或接近台站全年的极值。 因此, SPWVD时频方法研究和总结的异常特征对未来西部地区强震预报具有一定的积极作用。 相似文献
11.
We analyze variations in the rigidity spectrum of primary cosmic rays during Forbush effects recorded in cycles 20–24 of solar activity on the basis of data from the global network of neutron monitor stations processed by global survey. We investigate variations in the rigidity spectrum index of Forbush effects as a function of the solar activity level, phases of the effect, polarity the total magnetic field of the Sun, type and parameters of the source of cosmic ray modulation, etc. Comprehensive analysis of our results revealed regularities in the dynamics of the energy spectrum of galactic cosmic rays that reflect the dynamic processes occurring in the interplanetary space. 相似文献
12.
Using the spectrographic global survey method, variations in the rigidity spectrum and anisotropy of galactic cosmic rays
(March 1991) have been studied using data from ground-based observations of cosmic rays (CR) at the worldwide network of stations.
Variations in geomagnetic cutoff rigidity (GCR) have been calculated. The paper also presents latitudinal GCR variations at
certain moments of the considered period for different geomagnetic field disturbance levels. Calculation results of GCR variations
have been compared with those of effect of the westward current flowing with a strength proportional to the latitude cosine
along parallels on the sphere, for different radii of the current ring in the dipole field. 相似文献
13.
The variations in the rigidity spectrum and anisotropy of cosmic rays in December 2006 have been studied based on the surface measurements of the cosmic ray intensity at the global network of stations, using the method of global spectrographic survey. It has been indicated that the highest degree of anisotropy (to ～50%) with the maximal intensity of particles with a rigidity of 4 GV in the direction from the Sun (an asymptotic direction of about ?25° and 160°) was observed at 0400 UT on December 13. The parameters of the cosmic ray rigidity spectrum, which reflect the electromagnetic characteristics of the heliospheric fields during the studied period, have been determined when the surface and satellite measurements of protons in the energy range from several megaelectronvolts to several tens of gigaelectronvolts were jointly analyzed. The observed anisotropy and variations in cosmic rays in a wide energy range have been explained based on an analysis of the results. 相似文献
14.
The data from terrestrial observations of cosmic rays at the global network of stations by the method of spectrographic global survey were used to analyze two Forbush decreases during the geomagnetic storms in March and June 2015. The spectra of cosmic ray variations, pitch angle anisotropy of cosmic rays at different phases of Forbush decrease development, and the changes in the planetary system of geomagnetic cutoff rigidities are presented. It is shown that, during the approximation of the spectra of variations by the power function of particle rigidity in the interval of 10–50 GV, the spectrum index is softer at the maximum modulation phase than during the phases of cosmic ray intensity decline and recovery. In the axisymmetric model of the bounded magnetosphere of the Earth, which takes into account the currents at the magnetopause and the ring current, the distance to the subsolar point and the radius of the ring current, as well as the contribution of the ring current to the changes in geomagnetic cutoff rigidity and to the Dst index during the studied events, are determined. 相似文献
15.
V. K. Korotkov M. D. Berkova A. V. Belov E. A. Eroshenko P. G. Kobelev V. G. Yanke 《Geomagnetism and Aeronomy》2011,51(2):247-253
This paper describes a method, which makes it possible to eliminate the effect of snow cover from the neutron component of
secondary cosmic radiation. For many circumpolar, high-latitude, and mountain stations, where cosmic rays are continuously
registered, it is exclusively important to take the presence of snow into consideration. Comparisons are made for manual and
automated measurements, which are corrected for the snow effect based on the developed algorithm. The described method was
tested for a number of cosmic ray stations where considerable snow masses are accumulated during the winter period near or
above a detector: Magadan, Mount Hermon, Jungfraujoch, and Nain. 相似文献
16.
马钦忠 《地震学报(英文版)》2008,(6)
On July 4,2006,a MS5.1 earthquake occurred in Wen'an county of Hebei Province of which the epicenter is near the Beijing city.The six geoelectric field monitoring stations have been in operation for several years around the Beijing area to examine the relationship between electric field changes and earthquake.This paper firstly explains the principle of the eliminating noise method by using multi-dipole observation system of the geoelectric field.Then the data observed at the stations are studied and a lot ... 相似文献
17.
An index of cosmic ray scintillation introduced previously is verified. This procedure has been performed within the scope of the long-term full-scale monitoring of galactic cosmic rays (GCRs) in the real time regime. The 5-min data of the global network of high-latitude neutron monitors at Tixie Bay (Apatity) and Oulu (Finland) stations during the last four solar cycles (cycles 20–23), i.e., during the entire period of data registration with a high (5 min) resolution, have been used. The relationship between the amplitude-frequency-time structure of a precursor in the GCR scintillation index and the soliton-like structure of the heliospheric current sheet during the disturbed period has been established. This indicates that the precursor is of a coherent origin. Only the presence of a coherent process—quasi-week variation—makes it fundamentally possible to predict heliospheric storms. Finally, the justifiability of the effective prediction of heliospheric storms (～80%) has been obtained based on the long-term cosmic ray monitoring during cycle 23. 相似文献
18.
GPS技术在监测地震与地壳运动中已经得到应用，北京市地震局在北京市2002年启动建设的全球卫星定位综合应用服务系统基础上，于2003年开始GPS形变监测工作系统的建设，这是一个小区域连续的高密度GPS形变监测工作系统，获取高精度的北京市GPS基准站地心三维坐标，为地震监测和地壳运动的科学研究提供良好的GPS数据素材。 相似文献
19.
A. V. Belov E. A. Eroshenko V. G. Yanke V. A. Oleneva M. A. Abunina A. A. Abunin 《Geomagnetism and Aeronomy》2018,58(3):356-372
One of the variants of the global survey method developed and used for many years at the Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation of the Russian Academy of Sciences is described. Data from the world network of neutron monitors for every hour from July 1957 to the present has been processed by this method. A consistent continuous series of hourly characteristics of variation of the density and vector anisotropy of cosmic rays with a rigidity of 10 GV is obtained. A database of Forbush decreases in galactic cosmic rays caused by large-scale disturbances of the interplanetary medium for more than half a century has been created based on this series. The capabilities of the database make it possible to perform a correlation analysis of various parameters of the space environment (characteristics of the Sun, solar wind, and interplanetary magnetic field) with the parameters of cosmic rays and to study their interrelationships in the solar–terrestrial space. The features of reception coefficients for different stations are considered, which allows the transition from variations according to ground measurements to variations of primary cosmic rays. The advantages and disadvantages of this variant of the global survey method and the opportunities for its development and improvement are assessed. The developed method makes it possible to minimize the problems of the network of neutron monitors and to make significant use of its advantages. 相似文献