摘要
地表观测的重复重力数据综合反映了地表观测点的位置变化、地壳内部密度变化和地壳内部构造变形 ,通过反演这些数据得到的断层位错运动的时间变化综合反映了地壳内部形变和密度变化的耦合运动。为此 ,利用滇西 1985年以来的重复重力观测数据 ,结合地质调查和地球物理推断结果确定断层运动模型作为约束 ,并考虑到观测数据和模型粗差 ,反演获得了滇西主要活动断裂运动的时间变化分布。结果表明 ,滇西 1985～ 2 0 0 1年断层运动的时间变化表现出断层往复运动特征 ,较好地反映了区内Ms≥ 6 .0地震 (如 1996年丽江Ms7.0地震、1998年宁蒗Ms6 .2地震和 2 0 0 0年姚安Ms6 .5地震等 )的孕育过程。指出强震孕育过程遵循地壳内部密度和地壳形变耦合运动模式 (简称DD耦合运动模式 ) 。
The surface repeated gravimetric data can reflect synthetically the site changes of the surface measured points, the changes of crustal density and its tectonic deformation, the time changes of fault dislocation and its slip derived by inversion also reflect the coupling movement between crustal deformation and its density changes. In this paper we preliminarily inverted and obtained the time change distribution of the main active faults in the western Yunnan, using the repeated gravimetric data since 1985, combining with its geological investigation and geophysical results to determine the model of fault movement as restriction,and considering the gross errors of observation data and inverted model. The results show that the time changes of fault movement during 1985 to 2001 have the characteristics of reciprocating motion,and have preferably reflected the development process of the \%M\%s≥6.0 earthquake (such as Lijiang \%M\%s7.0 earthquake in 1996, Ninglang \%M\%s6.2 earthquake in 1998 and Yaoan \%M\%s6.5 earthquake in 2000) in study area. And we have pointed out that the seismogenic process follow the mode of the coupling movement between crustal deformation and its density changes (simply, DD mode of coupling movement), and have given the basic picture of the DD mode from fault dislocation movement.
出处
《大地测量与地球动力学》
CSCD
2002年第2期68-74,共7页
Journal of Geodesy and Geodynamics
基金
国家 973计划项目 (G19980 40 70 3 )
地震科学联合基金资助项目 (10 10 0 5 )
