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根据精密水准重复测量和跨断层形变观测资料,应用地壳形变图象动力学方法,研究了唐山地震震源区及其周围地区震前22年至震后9年间地壳形变场的时空演化过程.地壳不稳定区先出现在外围,由外向内扩展包围震源区,震源区出现不稳定但不失稳;经过短暂稳定,又出现由外向内的第2次不稳定过程,导致震源失稳.失稳前出现的“形变空区”与“地震空区”及“断层闭锁区”其空间分布重叠,出现时间略有先后;震源区断层出现临界预滑动后地震发生.地壳形变场演化过程与应力场数值模拟等研究结果能相互印证,支持以坚固体为核的孕震系统演化模式.
Based on the data of repeated measurements and data of stratigraphic deformation, the temporal and spatial evolution of the crustal deformation field from 22 years ago to 9 years after the earthquake in the focal region of the Tangshan earthquake and its surrounding area was studied by crust deformation image dynamic method. The crustal instability zone first appeared in the periphery, enlarging and surrounding the source area from outside to inside, and the source area appeared unstable but not destabilized. After a brief stabilization, the second instability process from outside to inside resulted in instability of the source. The spatial distribution of “deformed empty zone” before “unstable zone” and “earthquake zone” and “fault locked zone” overlap slightly with each other in sequence; the occurrence of the earthquake after the occurrence of the critical pre-slip in the source zone fault. The crustal deformation field and the numerical simulation of stress field can confirm each other and support the evolutionary model of the seismogenic system with solid as nucleus.