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1.
震前电磁辐射接收记录表明,河北张北地震前在北京,山西太原,河南安阳、洛阳记录到震前异常,这些异常全部在地震发生前结束,若在地震前能全面掌握这些异常,似能预报出河北张北地震。这些异常进一步表明电磁波接收仪能反映地震前兆。指出,为更好地发挥电磁波接收仪的作用,需要解决用计算机网络传递数据的问题。 相似文献
2.
There are many reports about the abnormal electromagnetic signals observed before great earthquakes. In particular, the signals of electromagnetic anomalies before the Hyogo-Ken Nanbu, Japan, MS=7.2 earthquake on January 17, 1995 (Hayakawa, et al, 1996) and those before the Loma Prieta, USA, MS=7.1 earthquake on October 19, 1989 (Fraser-Smith, et al, 1990) are especially remarkable. However, what the above authors reported are only the phenomena of one or two observatories. In order to … 相似文献
3.
汶川8．0级地震前电磁辐射异常变化特征初步研究 总被引：1，自引：0，他引：1
汶川8．0级地震前,距离震中只有35km的金河电磁波台记录到了宝贵的电磁扰动信息。本文分析了汶川5．12大地震前后该台的电磁波异常变化特征,表明：①强震前确实有电磁辐射异常存在,震前存在丰富的电磁扰动信息;②电磁扰动前兆异常在时间进程上有明显的阶段性变化特征,这可能是地震孕育不同阶段特征的反映。 相似文献
4.
通过省内、省外台站分布情况、台址情况、观测记录仪器使用情况,观测记录仪器的性能指标,如观测仪器探头类型、架（埋）设方式,记录仪器的采样率、分辨率,震例情况等从电磁辐射的发生机理出发进行深入细致的分析,找出地震前电磁辐射异常信息量、异常起始时间及持续时间与震中距、震级的关系。 相似文献
5.
《地震学报(英文版)》1996,9(3):447-454
In order to investigate the physical mechanism of seismo-electromagnetic signals, many scholars from China and other countries
have carried out laboratory and field experiments of rock samples by loading them up to fracture in recent ten-odd years.
In each of these experiments, the phenomenon of electromagnetic radiation was observed during the process of rock sample fracture.
However, the experimental results can not explain the non-synchronous electromagnetic radiation in actual observation records.
In these records, some stations displayed anomalies but some others did not, and the signals of different frequency bands
observed by the same station did not occur simultaneously. This has brought about many difficulties to the application of
electromagnetic radiation in earthquake prediction. The experimental result of this paper can explain the phenomenon of non-synchronous
electromagnetic radiation. In the experiment of this paper, rock samples are uniaxially compressed up to fracture. The antennas
of different frequency bands are installed two meters away from the rock sample in different directions. The electromagnetic
signals during the whole process of rock sample fracture are recorded synchronously by a 14-channel tape recorder. The experimental
results are as follows: (1) signals of the four frequency bands: VLF, MF, HF and VHF, are all recorded during the main fracturing
process of rock samples, but signals of different frequencies may somtimes occur non-synchronously; (2) the intensity of electromagnetic
radiation is the highest at the moment when the main fracture occurs, but signals in different directions are of different
intensities. The above results are consistent with the non-synchronous electromagnetic radiation observed in real earthquakes.
It seems possible to predict the orientation of future seismic source by the electromagnetic method of the LF or VLF frequency
bands.
Contribution No. 95A0075, Institute of Geophysics, SSB, China.
The paper is translated by Prof.Jie-Fan HUANG, Peking University from the Chinese into English version. 相似文献
6.
利用DEMETER卫星数据分析强震前后的电离层异常 总被引：1，自引：0，他引：1
基于法国DEMETER卫星观测的离子温度(Ti)、 VLF电磁场单频点频谱数据探索了2008年5月12日汶川MS8.0、 2010年1月12日海地MS7.3和2010年2月27日智利MS8.8等3次强震前后与地震有关的电离层异常现象. 结果发现, 汶川地震前3天(5月9日)震中北偏西方向离子温度明显升高, 震前4天(5月8日)VLF磁场低于200 Hz的频段范围频谱在震中2°以内有明显突升; 智利地震前9天(2月18日)震中北东方向离子温度有剧烈扰动, 震前4天(2月23日)VLF磁场100—160 Hz频段范围内出现突升; 海地地震震前没有观测到明显的异常现象, 但地震发生当天(震后约4—5小时)的Ti, 40—160 Hz频段电场频谱, 以及120—480 Hz磁场频谱均有明显突升, 应为地震发生后能量释放所引起. 分析认为, 不同地震由于发震机制等各种情况的不同, 其地震前后的表现也各不相同. 虽然目前没有直接的证据表明本文研究的异常变化是由地震的孕育和发生引起的, 但在数据处理中已尽可能排除了太阳、 地磁等因素的影响, 并且研究结果与前人的研究经验吻合, 因此本文发现的异常可能与地震发生的关系较大. 相似文献
7.
本文分析了2010年10月-2011年3月云南通海ELF地震台站观测的电磁场资料,研究发现该资料变化与2011年发生在中国大陆"3·10"盈江5.8级及"3·24"缅甸7.2级地震存在以下关系,(1)470～1 Hz的磁场自功率密度谱(PSD)在2011年盈江5.8和缅甸7.2级地震前出现了脉冲丛集异常,异常幅度分别比正常月份变化约1～3个数量级.异常的幅度与观测点的电极方位和信号的频率有密切的关系.(2)2011年3月10日盈江地震的异常变化是先从地壳的深部向浅部发展,在震前25天2.6 km处的电阻率开始发生变化,震前10天400 m处的电阻率变化,出现了勺形的变化形态,阻抗相位同步变化.3月24日的缅甸7.2级地震,震前10天深部、浅部的电阻率同步发生了大幅度变化,阻抗相位发生转折,这可能是强震的变化特性. 相似文献
8.
Network of seismo-geochemical monitoring observatories for earthquake prediction research in India 总被引：2，自引：0，他引：2
Hirok Chaudhuri Chiranjib Barman A. N. Sekar Iyengar Debasis Ghose Prasanta Sen Bikash Sinha 《Acta Geophysica》2013,61(4):1000-1025
Present paper deals with a brief review of the research carried out to develop multi-parametric gas-geochemical monitoring facilities dedicated to earthquake prediction research in India by installing a network of seismo-geochemical monitoring observatories at different regions of the country. In an attempt to detect earthquake precursors, the concentrations of helium, argon, nitrogen, methane, radon-222 (222Rn), polonium-218 (218Po), and polonium-214 (214Po) emanating from hydrothermal systems are monitored continuously and round the clock at these observatories. In this paper, we make a cross correlation study of a number of geochemical anomalies recorded at these observatories. With the data received from each of the above observatories we attempt to make a time series analysis to relate magnitude and epicentral distance locations through statistical methods, empirical formulations that relate the area of influence to earthquake scale. Application of the linear and nonlinear statistical techniques in the recorded geochemical data sets reveal a clear signature of long-range correlation in the data sets. 相似文献
9.
Manana Kachakhidze Nino Kachakhidze-Murphy Giorgi Khazaradze Badri Khvitia 《地震科学（英文版）》2021,34(2):168-176
It is widely known that very low frequency/low frequency (VLF/LF) radiation has been recorded prior to large earthquakes in several seismically active countries of the world. The networks employed to detect this radiation consist of stationary transmitters and receivers. However, there are reported cases of existing networks being unable to detect any electromagnetic radiation prior to large earthquakes. In this study, we determined the optimal arrangement of a mobile VLF/LF electromagnetic radiation network to ensure the detection of an upcoming earthquake precursor. We consi-dered the possible arrangements of the VLF/LF mobile network based on certain physical considerations, and deve-loped a relatively simple arrangement that is completely different from the existing stationary networks. The suggested design will significantly increase the number of detected/predicted earthquakes by using the relevant electromagnetic radiation receivers strategically placed in regions of increased tectonic and seismic activity. 相似文献
10.
11.
叙述了地震时埋地管道可能遭受的破坏形式、影响管道震害的因素及破坏等级的划分。论述了用模糊数学法进行埋地管线震害预测的方法和步骤，利用这一方法对忻州市供水管网主干线进行了震害预测，给出了在地震烈度Ⅶ度～Ⅸ度作用下的震害预测结果。 相似文献
12.
By use of the specialized under ground electrodes as the sensor, the Experimental Multi-station Network observed Seismic Electromagnetic
radiationsprior to the moderately strong earthquake. From the great number of electromagnetic anomalies recorded by the network continuously
for about 10 years, it can be sure that the anomalies are related to earthquakes aboveM
s 5 within 300 km. The stronger the magnitude of the earthquake is, the better the relation is. The abnormal electromagnetic
radiation information appears in a short-time before the moderately strong earthquake. The continuous automatic pen recording
shows that the electromagnetic information is the waveform of the paroxysmal wave group, and has the features of undulating
enhancement, amplitude in inversely proportion to epicentral distance, frequency increase, regional similarity of wave froms
and directivity, etc.. It also contains some quantitative elements related to the parameters of the earthquake. The above
characteristics and correlative elements can provide important bases for predicting the three elements of the earthquake.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 83–90, 1993.
Associate Professor Da-Yuan CHANG and Teacher Feng CHEN have gave us a lot of help during the study. 相似文献
13.
14.
—The 1989 M s = 7.1 Loma Prieta earthquake was preceded for 12 days by what have been claimed as precursory ultra-low-frequency (ULF) magnetic noise anomalies ten times background, and by a very high peak up to 100 times background just 3 hours before the earthquake. We propose that these anomalous fields could have been due to the formation of a long thin highly-conductive region along the earthquake fault, which magnified the external electromagnetic waves incident on the earth’s surface. We use a simplified quantitative model, assuming a highly-conductive elliptic cylinder embedded in a layered resistivity structure, which we base on independent magnetotelluric measurements. The magnetic-field anomaly observed 3 hours before the main shock can be modeled by assuming an elliptic conductor extending from the surface to the hypocenter with a conductivity of 5 S · m?1. Our computed anomaly matches the observed anomaly to within a deviation of 35% over an observed frequency range of over 2 orders of magnitude, over which the measured anomaly varies from only about twice background (at 5 Hz) to about 100 times background (at 0.01 Hz). In addition, other anomalies recorded up to 12 days before the earthquake, can be modeled in detail by varying only the size of the elliptic conductor.¶We show that such an increase in conductivity could be caused by a precursory reorganization of the geometry of fluid-filled porosity in the fault-zone, which we call a dilatant-conductive effect. The extreme observed magnetic anomalies can be modeled using the high fault-zone porosity (c. 10%) and fluid conductivity (equivalent to 2 M NaCl) implied by other workers’ magneto-telluric measurements, but without requiring the large-scale precursory fluid flow characteristic of other published models for the magnetic-field precursors. 相似文献
15.
2009年利用大功率人工源极低频电磁技术(CSELF)在位于华北、华南、东北、西北和西南的12个地震台站和几个流动观测点进行了连续30天新的观测试验.结果表明,利用CSELF技术可以在1700 km之外测量到人工源电磁场信号,计算得到的电、磁场功率谱密度和视电阻率与天然源信号相比,抗干扰能力更强,观测信号更稳定,特别有利于识别和捕捉地震等诱发的电磁异常现象,在地震预测监测中具有很大的研究应用潜力.试验还发现,各地震台站和流动测点观测的CSELF信号的强度,与台站或者测量的电、磁场分量相对于发射源的距离、方位有明显的关系;发现在离开发射源的相对近区,场强随距离的衰减,比在相对远区更快;发现接收磁场信号比电场信号较易获得更高信噪比的数据. 相似文献
16.
Introduction The occurrence of earthquake has relations not only with seismogenic process of source area,but also with the environment of inner (earth space) and outer (earth-sun space). The varyinggeomagnetic field is natural medium that connects with both factors (DING, 1988). There are two kinds of basic ideas using the diurnal-variation anomalies of the verti-cal-component (Z) in geomagnetic field to predict earthquake. The first kind is local geomagneticanomalies that are obta… 相似文献
17.
In order to add earthquake monitoring methods and develop new method research, the ELF Network for Earthquake Monitoring selected 30 stations in the Capital Circle and the Sichuan-Yunnan region. Finding electromagnetic field background variation is the basis of distinguishing the seismic electromagnetic anomalies. This paper introduces the data acquisition and selection of the Shexian, Anqiu, Lijiang and Dali stations which have recorded for longer time with better data and are located on the similar latitude. Then we use the natural source electromagnetic field''s auto-power spectrum to express the intensity of the electromagnetic field. By using power spectral data of many frequencies in the observation frequency band, after the data pre-processing and sliding average noising, the background variation of extremely low frequency stations and the range ability were acquired. Taking the Baoshan M5.1 earthquake on October 30, 2015 and Dali M5.0 earthquake on May 18, 2016 as examples, the authors analyzed the earthquake electromagnetic anomaly characteristic of ELF stations around the earthquakes. 相似文献
18.
对于电磁卫星所观测到的地震震前电磁异常现象的机制，即电磁异常如何从岩石圈穿过大气层耦合到电离层及其以上空间，目前仍是尚未解决的问题.本文主要介绍目前大量有关地震岩石圈异常的机制研究，力图从卫星地震电磁异常的源头—岩石圈地震来获得相关认识.岩石圈地震前兆异常包括：地表变形、水位变化、悬浮薄雾、超低频（ULF）电磁异常、山脊或山顶发光闪电、卫星红外图片大范围数度温度异常、磁场高于地磁偶极场的0.5%、电离层等离子体密度变化、动物奇异行为等.人们提出了许多试图解释各种异常现象的假说，如热耦合假说、气泡运移假说、边界位错充电假说、离子空穴运移假说等.本文希望通过对以上各种假说提出的基础、物理机理以及异常现象解释的探讨，促进对岩石圈地震前兆异常现象机理认识，从而为地震电磁异常的正确认识提供更有力的帮助. 相似文献
19.
ELECTROMAGNETIC ANOMALOUS PULSES BEFORE AND AFTER EARTHQUAKES(M>6.0) IN CHINA CONTINENT IN 2008 
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下载免费PDF全文 In this paper,we provided the electromagnetic anomaly phenomena prior to five earthquakes with magnitude MW>6.0 occurring in China continent in 2008.The electromagnetic data in frequency bands 800~0.1Hz are recorded at two stations located in Urumqi,Xinjiang Uygur Autonomous Region (URQ) and Tonghai,Yunnan Province (TH).The time series of four horizontal components of the electromagnetic field at the stations are converted to the spectra using Fast Fourier Transform.The relationship between the electromagnetic anomalous phenomena and the earthquake events is studied through analyzing the temporal variation of electromagnetic spectra and comparing them with earthquake events.This study provides the new examples for electromagnetic anomaly phenomena before the earthquakes.The following features can be found.①The obvious anomalous power spectrum density (PSD) of electromagnetic fields in frequency band of 128~0.5Hz appeared before earthquakes.The anomalous PSD is related to the earthquake magnitude and the epicenter distance.The anomaly size of magnetic PSD is about 1-3 orders of magnitude bigger than the background field before Wenchuan MS8.0 earthquake.② The changes of parameters are also related with frequency of the signal;The ELF signal strength observed at seismic stations is significantly related with distance between the stations or the measured magnetic and electrical field components and the source of earthquake.We also found that the field strength attenuated faster in area closer to the source than in far area.It is clear that the magnetic signals have higher signal noise ratio than the electric data.③ The amplitudes are also related with the azimuth of the earthquake to station and with the frequency of the data.④ The anomalous pulses showed cluster phenomenon in time. 相似文献
20.
小波极大值方法及其在电磁异常信号提取中的应用 总被引：2，自引：2，他引：0
小波极大值法作为一种数据挖掘技术已经受到关注,并在地震科学研究领域开始进行应用研究。它能在长时间的观测数据中快速提取出不同时间、不同频率的有关异常信息。文中介绍了如何应用小波极大值法提取电磁场异常信息,即利用连续小波变换计算小波系数,计算各尺度小波系数的极大值,结合表征信号奇异性的Lipschitz指数分析异常的真实性,进而研究极大值在时间分布上的特点或规律,捕捉有关的电磁异常现象。利用该方法对2013年4月20日四川芦山7.0级地震后35d的连续观测的电磁场数据进行了分析,发现存在3次电磁场异常,探讨了这些异常可能与地震活动性之间存在的关系。尽管用这种方法尚不能确定发现的电磁场异常现象与地震有某种特定的关系,但是证明了小波极大值方法在连续观测数据中提取电磁异常现象的有效性。 相似文献