【摘要】 通过对丽江地区构造格架和丽江大震的震后调查 ,对丽江地震的发震环境进行了系统分析 ,认为丽江地震是在主压应力为近NS向区域应力场作用下 ,NE向丽江 小金河断裂左旋错动和NW向中甸 永胜断裂右旋错动 ,从而导致巨甸—九子海三角形断块东部近尖端部位出现局部拉张环境 ,最终导致近NS向西倾的玉龙雪山东麓断层北端撕裂而发震 .更多还原

【Abstract】 Based on the study of the regional tectonic framework and investigations of the Lijiang M S7.0 earthquake in 1996,the earthquake generating environments are systematically analyzed.Under the action of potential regional nearly NS compressive stress field,the sinistral slip of the NE strike Lijiang Xiaojinhe fracture and right lateral slip of NW strike Zhongdian Yongsheng fracture resulted in local and extension environment in the eastern triangle end of Yulongxueshan Jiuzihai faulted block, at last the north end of the nearly NS strike and dipping westwards Yulongxueshan’s east piedmont fault was ripped up and the Lijiang M S7.0 earthquake happened.更多还原