关键词: 耿马地震, 破裂带, 位错, 滑动矢量, 应力

Abstract: In this paper from the data of field investigation,a surface rupture zone of the Ge-ngma earthquake in Yunnan Province is studied. Meanwhile,a dislocation model of the tension-torsion fault type is suggested from the data on fault dislocation. It is shown that the seismogenic structure for the Gengma earthquake is dominated by right-lateral horizontal offset with horizontal extension. The maximum dislocation is 1.6 meter and the maximum strike slip is 0.96 meter. The preferred direction of sliding vector is NW-SE 55°at a dip angle about 30—40°. The result of stress analysis suggests that the preferred direction of principal compressive stress is N5—10° E at an elevation angle about 40—60° in the earthquake area.

Key words: Gengma earthquake, Rupture zone, Dislocation, Sliding vector, Stress