Electromagnetic anomaly before earthquakes measured by electromagnetic experiments

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• 作者：Guoze Zhao (1)
  Yan Zhan (1)
  Lifeng Wang (1)
  Jijun Wang (1)
  Ji Tang (1)
  Qibin Xiao (1)
  Xiaobin Chen (1)
  
• 关键词：electromagnetic anomaly ; apparent resistivity ; artificial SLF method ; EM experiment ; magnetotellurics ; P318.6
• 刊名：Earthquake Science
• 出版年：2009
• 出版时间：August 2009
• 年：2009
• 卷：22
• 期：4
• 页码：395-402
• 全文大小：402KB
• 参考文献：1. Bleier T and Freund F (2005). Impending earthquake have been sending us warning signals and people are starting to listen. / IEEE, / Spectrum Int 12: 17-1.
  2. Bureau of Geology and Mineral Resources of Hebei Province (1989). / Regional Geology of Hebei Province. Geological Publishing House, Beijing, 566-84 (in Chinese).
  3. Huang Q (2002). One possible generation mechanism of co-seismic electric signals. / Proceedings of the Japan Academy 78(7): 173-78. CrossRef
  4. Johnston M and Uyeda S (1999). Electromagnetic methods for monitoring earthquakes and volcanic eruptions. / IUGG99 / Abstract. Birmingham, July 19-0, A72–A83.
  5. Ma X Y (1989). / Lithospheric Dynamics Atlas of China. China Cartographic Publishing House, Beijing, 20 (in Chinese with English abstract).
  6. Ma Z J, Fu Z X and Wang C M (1982). / Nine Strong Earthquakes in China. Seismological Press, Beijing, 1-16 (in Chinese).
  7. Mizutani H, Ishido T, Yokokura T and Ohnishi S (1976). Electrokinetic phenomena associated with earthquakes. / Geophys Res Lett 3: 365-68. CrossRef
  8. MT Group of Institute of Geology, State Seismological Bureau (1981). The crustal structure and its variation before and after Tangshan earthquake. In: MT Group of Institute of Geology, State Seismological Bureau and MT Group of Lanzhou Institute of Seismology, State Seismological Bureau eds. / Magnetotellurics. Seismological Press, Beijing, 89-5 (in Chinese).
  9. Parrot M (2002). The micro-satellite DEMETER. / Geodynamics 33: 535-41. CrossRef
  10. Qian F, Zhao B, Qian W, Zhao J, He S and Zhao Y (2009). HRT wave precursor before Wenchuan / MS8.0 earthquake and HRT wave predicting methods. / Science in China ( / Series D) 39(1): 11-3 (in Chinese).
  11. Reddy I K, Phillips R J, Whitcomb J H, Cole D M and Taylor R A (1976). Monitoring of time dependent electric resistivity by magnetotelluric. / J Geomagn Geoelec 28(2): 165-78.
  12. Saraev A, Petrel M and Molkin Z (2002). Correction of the electromagnetic monitoring data for tidal variations of apparent resistivity. / J Appl Geophys 49: 91-00. CrossRef
  13. State Seismological Bureau (1982). / Tangshan Earthquakes in 1976. Seismological Press, Beijing, 296-14 (in Chinese).
  14. Tang J, Zhao G Z, Wang J J, Li W J and Zhan Y (1998). Variation and analysis of resistivity before and after Zhangbei-Shangyi earthquake. / Seismology and Geology 20(2): 164-71 (in Chinese with English abstract).
  15. Tselentis G-A and Melis N S (1996). A note on evaluating VAN earthquake predictions. / Geophys Res Lett 23(11): 1 411- 414.
  16. Wang J, Shi S, Sun J, Jiang Z, Jin G, Xu C, Guan H and Bao Z (1993). The suggestion on the determining the earthquake factors using MT method and the preliminary observation. In: Liu G D and Deng Q H eds. / The Investigation on Electromagnetic Methods and the Prospecting. Seismological Press, Beijing, 269-79 (in Chinese).
  17. Yang Z X and Chen Y T (2004). Relocation of the 1998 Zhangbei-Shangyi earthquake sequence using the double difference earthquake location algorithm. / Acta Seismologica Sinica 17(2): 125-30. CrossRef
  18. Zhang Y, Ke Y, Guo S and An J (1987). To monitoring the electricity variation in the crust by MT. / Northwestern Seismological Journal 19(l): 54-1 (in Chinese with English abstract).
  19. Zhang Y, Liu X, An J and Jiang M (1994). Application of the MT repeated measurements to the medium and short term prediction of earthquake: Monitoring and studying a profile in the middle segment of Qilian Mountain by MT. / Chinese J Geophys 37(4): 200-10 (in Chinese with English abstract).
  20. Zhao G Z, Chen X B and Cai J T (2007a). Electromagnetic observation by satellite and earthquake prediction. / Progress in Geophysics 22(3): 667-73 (in Chinese with English abstract).
  21. Zhao G Z, Chen X B and Tang J (2007b). Advanced geo-electromagnetic methods in China. / Progress in Geophysics 22(4): 1 171- 180 (in Chinese with English abstract).
  22. Zhao G Z, Chen X B, Wang L F, Wang J J, Tang J, Wan Z S, Zhang J H, Zhan Y and Xiao Q B (2008). Evidence of crustal ‘channel flow-in the eastern margin of Tibetan Plateau from MT measurements. / Chinese Science Bulletin 53(12): 1 887- 893. CrossRef
  23. Zhao G Z, Tang J, Deng Q H, Wang J J, Chen X B, Zhan Y, Xuan F, Saraev A K, Pertel M I, Kotcherov A B, Khalmov M M and Zhai Y Z (2003). Artificial SLF method and the experimental study for earthquake monitoring in Beijing area. / Earth Science Frontiers 10(Suppl): 248-57 (in Chinese with English abstract).
  24. Zhao G Z, Tang J, Zhan Y, Chen X, Zhuo X, Wang J, Xuan F, Deng Q and Zhao J (2005). Relation between electricity structure of the crust and deformation of crustal blocks on the northeastern margin of Qinghai-Tibet Plateau. / Science in China ( / Series D) 48(10): 1 613- 626. CrossRef
  
• 作者单位：Guoze Zhao (1)
  Yan Zhan (1)
  Lifeng Wang (1)
  Jijun Wang (1)
  Ji Tang (1)
  Qibin Xiao (1)
  Xiaobin Chen (1)
  
  1. Institute of Geology, China Earthquake Administration, Beijing, 100029, China
  
• ISSN：1867-8777

文摘

Three experiments are carried out for earthquake monitoring using electromagnetic (EM) methods in recent years. Some earthquakes occurred in chance of the measurement time period for each experiment and the anomalies were recorded before the shocks. The observation at a site 20 km away from the epicenter of Zhangbei M S6.2 earthquake in 1998 shows that the apparent resistivity decreases in the strike direction before and/or during the earthquake and the resistivity increases in the decline direction. This anomalous variation in apparent resistivity accounts for about 20%. The apparent resistivities at a site in the epicentral area decrease in the strike and decline directions before and/or during the earthquake and increase after shocks. The experiments using artificial electromagnetic signals with super low frequency carried out in 1999 show that the resolution and stability of electric and magnetic spectra are improved. The spectra of electric and magnetic fields and apparent resistivity at the Baodi station began to anomalously change two days before the Qian’an earthquake with 120 km distant to the station. The anomalous variation of electric and magnetic spectra is about twice as great as normal variation and the apparent resistivity changes by about 20%. The measurements in active seismic area of Yunnan province in the year 2005 indicate that the electric and magnetic spectra anomalously change by one order before the Taoyuan earthquake about 100 km away from the observatories. But the measurements at the sites in Beijing area 2 000 km away from the epicenter do not show any anomaly.