山西带形变监测场地情况调查

对山西带跨断层短水准流动测量场地、定点台站跨断层水准场地和区域流动GPS场地及分布情况进行了调查、汇总和分析。调查了10个流动水准测量场地和4个定点台站水准测量场地,所跨断层绝大多数走向为北北东至北东向,多具有右旋正走滑活动性质,反映了山西带总体构造特征。同时发现,偶有近东西向断裂或北西向断裂与其互相切割,应该是容易造成应力集中的地方。整个山西带布有区域GPS观测点40个,每年正常观测1次的有39个,点距多为几公里到几十公里不等,在整个断层带上的分布比较均匀,并已积累了十几年的流动观测资料。结合地质资料和历史地震的活动特点,认为山西带再次孕育强震的可能性较大,这些多手段形变测量场地的布设情况、时间和空间上的相互联系及多年复测资料的积累对强震预测研究有重要价值。

Investigation on Monitoring Sites of Crustal Deformation in Shanxi Seismic Belt

In this paper,several kind of crust deformation monitoring sites including mobile short leveling site across faults,station leveling sites and the regional mobile GPS monitoring sites in Shanxi seismic belt are investigated,analyzed and summarized.Most of the monitoring data in Shanxi including from 10 mobile short leveling sites and 4 station leveling sites have shown the general features of Shanxi seismic belt：most of the faults’ strikes are NNE to NE,and with the active way of normal right-lateral strike slip.Besides,these faults and few other faults with direction of near east-west or north-west are cut each other where is the place likely to cause stress concentration.There are 40 regional GPS spots in Shanxi seismic belt,and 39 spots are observed once a year.The distance between two adjacent spots is from a few kilometers to dozens of kilometers,and they are well distributed on the fault zone.Re-monitoring data from these spots have been accumulated more than ten years.From study on the feature of historic seismicity and the geological data,it’s considered that strong earthquake will come again more possibly in Shanxi belt.Thus information about different kinds of crust deformation monitoring sits,the relationship between the sites in time and space,and the accumulation of years monitoring data are all important for researches on earthquake prediction.