【摘要】 用云南地区地倾斜观测资料 ,分析研究了澜沧—耿马 7 6级地震、丽江 7 0级地震前的趋势性变化的典型特征 ,认为在云南 7 0级以上地震前 ,云南地区地倾斜各分项测值在震前 3年内普遍存在一些典型变化形态特征 :东西向大多数表现为首先加速东倾 ,然后又反向加速西倾的典型特征 ;北南向有的表现首先加速南倾 ,然后又反向加速北倾的典型特征 ;有的表现首先加速北倾 ,然后又反向加速南倾的典型特征。这个过程开始加速和反向加速的时间虽不一致 ,开始加速一般在震前 3年左右 ,而且似乎距离震中越近的测项 ,反向加速出现的越晚 ,其速率也较大。更多还原

【Abstract】 Based on the data of tilt observation at the fixed sites in Yunnan Province, the typical characterics of trend variation of tilt deformation before the occurren ce of M7 6 Lancang-Gengma earthquake and M 7 0 Lijiang earthqu ake are studied in this paper. The conclusion is made that 3 years before the oc crrence of M≥7 0 e arthquakes in Yunnan Province, the fixed deformation has the following features. In the east-west direction, the ground tilts acceleratedly toward east direct io n and then tilts acceleratedly toward the west direction. In some of the field o bservational sites, In the North-South direction the ground tilts acceleratedl y toward the south direction and then tilts acceleratedly toward the North. In oth er observational sites, the ground tilts acceleratedly toward the North and then tilts acceleratedly toward the South. Genarally, the ground begins to accelerat e to tilt about 3 years before the strong earthquake. It seems that the closer t he observational sites get to the epicenter, the later the reverse-acceleration time will be. In the same way, the closer the observational sites get to the epi center, the larger the velocity will become.更多还原