CRUSTAL DEFORMATION ASSOCIATED WITH THE HSINGTAI (邢台) EARTHQUAKE IN MARCH, 1966
THE GEODETIC SURVEY BRIGADE FOR EARTHQUAKE RESEARCH, NATIONAL SEISMOLOGICAL BUREAU
The Hsingtai Earthquake in March 1966 was an earthquake swarm. Five strong shocks with magnitudes of 6.0 or greater occurred in the strongly subsiding Shulu (束鹿) Graben of the Hsingtai-Hengshui (邢台-衡水) Upheaval. The results of le-velling survey show significant subsidence in the graben area before, during and after the seismic active periods. The results of the geodetic survey suggest a dislo-cation model of the tension-torsion fault type, mainly of right lateral horizontal offset, accompanied by movements of horizontal extension and vertical subsidence for the Hsingtai Earthquake. The repeated levellings during the intervals between the two main shocks and other strong shocks reveal that strong subsidence took place in the epicentral area of strong shocks while in area of probable future shocks conspi-cuous uplift was observed. The vertical crustal deformation before and after the Hsingtai Earthquake has probably 4 stages, characterized in general by deformation in the same direction.