GONG SHAOJING, WU ZIIANFENG. 1986: POSSIBLE CHANGES OF EARTH CONDUCTIVITY ACCOMPANYING THE TANGSHAN EARTHQUAKE OF 1976. Acta Seismologica Sinica, 8(1): 28-36.
Citation: GONG SHAOJING, WU ZIIANFENG. 1986: POSSIBLE CHANGES OF EARTH CONDUCTIVITY ACCOMPANYING THE TANGSHAN EARTHQUAKE OF 1976. Acta Seismologica Sinica, 8(1): 28-36.

POSSIBLE CHANGES OF EARTH CONDUCTIVITY ACCOMPANYING THE TANGSHAN EARTHQUAKE OF 1976

More Information
  • Published Date: August 31, 2011
  • Time changes in transfer functions of short period geomagnetic variations are studied in order to investigate the possible anomaly of earth conductivity in relation to the Tangshan earthquake of 1976. The results indicate that there are appreciable negative anomalies in the transfer functions A at two observatories located respectivily 5 km and 60 km from the aftershock area. But the anomalous change of A is not obvious at another observatory, 145 km to the west of the aftershock area. If anomalous change of earth conductivity exists, then the depth of greatest change is that corresponding with the period of 14—20 min., and the inclination of the boundary of the conductor under ground may have decreased about 2.7°at Changli.
  • [1] Yangihara, K., Secuiar variation of the electrical conductivity anomaly in the central part of Japan, Mem. Kakioka Mag. Obs., 15, 1—11, 1972.

    [2] Rikitake, T., Changes in the direction of magnetic vector of short—period geomagnetic variations before the 1972 Sitka, Alaska, earthquake, J. Geomagn. Geoelec. 31, 441—448, 1979.

    [3] Chen Bofang(陈伯舫),A search for correlation between time change in transfer functions and seismic activity in north Taiwan, J. Geomagn. Geoelec., 33, 635—643, 1981.

    [4] Miyakoshi, J., Secular variation of Parkinson vectors in a seismically active region of middle Asia, J.Fac. General Education, Tottori Univ., 8, 209——218, 1975.

    [5] Beamish, D., A geomagnetic precursor to the 1979 Carlisle earthquake, Geophys. J. R. as}r. Sac., 68, 531—543, 1982.

    [6] 中国科学院数学研究所数理统计组,迥归分析方法,科学出版社,1974.

    [7] 陈伯舫,渤海西岸的电导率异常,地球物理学报,17, 169—172, 1974.

    [8] 祁贵仲、詹志佳、侯作中、范国华、王志刚、白彤霞, 渤海地区地磁短周期变化异常,上地慢高导层的分布及其与唐山地震的关系,中国科学, 7, 869—879, 1981.

    [9] Rikitake, T, Crustal dilatancy and geomagnetic variations of short period, J. Geomagn., Geoelec.,28, 145—156, 1976.
  • Related Articles

Catalog

    Article views (1019) PDF downloads (107) Cited by()

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return