摘要
由倾斜断层的静态位错模式计算了唐山地震引起的剩余倾斜场的空间分布和泰安等倾斜仪台站处的理论倾斜阶跃,讨论了按不同震源参数计算得到的剩余倾斜场的空间分布特征和断层参数对倾斜变化的影响。各台站倾斜阶跃的观测值是:泰安,1.4×10^(-8)(北),1.1×10^(-7)(东);沙城,2.4×10^(-7)(北);易县,-1.3×10^(-7)(西),单位为弧度。观测值与理论计算值的比较表明,观测的和计算的倾斜阶跃的方向是一致的,但数值上观测值较大。观测的和计算的倾斜阶跃方向的一致性说明了观测到的阶跃与地震的关系,而观测值较大则说明观测的倾斜阶跃仍包含其他局部因素的影响。观测倾斜阶跃的上升时间约3小时。分析表明,它可能是地震滑动和无震缓慢蠕动的综合效应。
Spatial distributions of residual tilt field and tilt steps at Tai-an,Sha-cheng and Yi-xian stations due to Tangshan earthquake were calculated by using the dislocation model for an inclined fault and characteristics of the spatial distribution as well as the effects of source parameters on the tilt are discussed here in detail.The observed tilt steps are as follows:Tai-an,1.4×10^(-8)(N),1.1×10^(-7)(E);Sha-cheng,2.4×10^(-7)(N);Yi-xian,-1.3×10^(-7)(W)Bad.A comparison of the observed and theoretical tilt steps indicates that the senses of the tilt steps at these stations are in good agreement.It shows that the observed steps are closely related to the earthquake,but on the other hand,the magnitudes of all the observed steps are larger than the calculated ones.It seems that there are still other effects which would affect the tilt steps observed.The rise-time of observed steps is nearly 3 hours;it seems to support the idea that the observed steps are caused by both seismic and aseismic slips during the process of earthquake.
作者
李兴才
陈运泰
LI XING-CAI;CHEN YUN-TAI(Institute of Geophysics,State Seismological Bureau)
出处
《地球物理学报》
1982年第3期219-226,共8页
Chinese Journal of Geophysics
