莱州M4.6地震前山东形变异常特征

摘要

The leveling data crossing fault in Changjiazhuang,the NS component of tiltmeter in Yantai and gravity data in Taian before Laizhou M4.6 earthquake were analyzed.The result shows that each of the 3 kinds of observation data appeared mid-term or short-term trend abnormities.The characteristics of the abnormities is:the closer of the distance from epicenter,the earlier it occured,and the farther from epicenter,the longer it lasted for.The distance away epicenter of the farthest abnormal point reaches 276 km,and the abnormities are connected to the geological structure.%分析莱州M4.6地震前山东形变观测存在的常家庄跨断层流动短水准、烟台水平摆倾斜NS向和泰安重力异常变化特征.结果显示,3个观测分量的异常均为中、短期趋势异常,震中距最小的异常出现的最早,持续时间最长;震中距最大的异常出现的最晚,持续时间最短.异常点分布在震中周围276 km范围内,且与地质构造有一定关系.结合地质构造和地震活动性探讨了异常产生的可能机理.