pure and applied geophysics

, Volume 124, Issue 4–5, pp 941–955 | Cite as

A possible change in stress field orientation due to the 1976 Tangshan earthquake

  • Zhonghuai Xu
  • Suyun Wang


Two techniques are used to study the stress field in the Tangshan region. First, the mean directions of principal stress axes in three subregions of the Tangshan aftershock region are determined from 29 focal mechanism solutions. In doing so a slip-fitting technique is applied which determines the mean stress tensor by minimizing the angle between the observed slip direction on every fault plane and the calculated shear stress resolved onto the fault planes. Each of the two nodal planes of the focal mechanism solutions are alternately considered as a possible fault plane. Second, by making a grid search over all possible orientations of stress axes, the meanP,B andT axes in the Tangshan region, both before and after the Tangshan mainshock, are found on the basis of firstP-wave polarity readings from a number of small earthquakes. The results indicate that there is a possible azimuthal change of the principal stress axes in the focal region due to the occurrence of the mainshock.

Key words

Stress orientation change Tangshan earthquake 


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  1. Angiller, J. (1979),Determination of mean principal direction of stresses for a given fault population. Tectonophysics56, T17-T26.Google Scholar
  2. Angillier, J. (1982),Inversion of field data in fault tectonics to obtain the regional stress. I.Single phase fault populations: A new method of computing the stress tensor, Geophysics. J. R. astr. Soc.,69(3), 607–622.Google Scholar
  3. Ellsworth, W. L. andXu Zhonghuai (1980),Determination of the stress tensor from focal mechanism data EOS61, 117.Google Scholar
  4. Ellsworth, W. L. (1981),A general theory for determining the state of stress in the Earth from fault slip measurements, Terra Cognita2(2), 170–171.Google Scholar
  5. Etchecopar, A., Vasseur, G. andDaignieres, M. (1981),An inverse problem in microtectonics for the determination of stress tensor from fault striation analysis, J. Struct. Geol.3(1), 51–55.Google Scholar
  6. Hebei Provincial Seismological Bureau. The Catalog of Tangshan Earthquakes, (Seismological Press, Beijing, 1980)Google Scholar
  7. Li Qin-zu, Diao Guiling andDai Yinghua (1983),The stress release and adjustment process during Tangshan earthquake sequence, Acta Geophysica Sinica26(3), 224–236.Google Scholar
  8. Smirnov, F. E. (1956),Courses of advanced mathematics Vol. 3, 1 (Originally in Russian, translated into Chinese).Google Scholar
  9. Wang Suyun andXu Zhonghuai (1985),Seismo-tectonic stress field in east China, Acta Seismologica Sinica7(1), 17–32.Google Scholar
  10. Xu Zhonghuai, Yan Ming, andZhao Zhonghe (1983),Evaluation of the direction of tectonic stress North China from recorded data of a large number of small earthquakes, Acta Seismologica Sinica5(3), 268–279.Google Scholar
  11. Yamakawa, N. (1971),Stress fields in focal regions, J. Phys. Earth19, 347–353.Google Scholar
  12. Zoback, M. L., andZoback, M. (1980),State of stress in the conterminous United States, J. Geophys. Res.85(B11), 6113–6156.Google Scholar
  13. The 1976 Tangshan Earthquake. Edited by a special editorial group under the Chinese State Seismological Bureau (Seismological Press, Beijing, 1982), pp. 459 (in Chinese).Google Scholar

Copyright information

© Birkhäuser Verlag 1986

Authors and Affiliations

  • Zhonghuai Xu
    • 1
  • Suyun Wang
    • 1
  1. 1.Institute of GeophysicsState Seismological BureauBeijingChina

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