台湾美浓Mw6.4地震InSAR形变场初步分析

摘要

On February 6,2016,a Mw6.4 earthquake occurred in Meinung district of Kaohsiung city,Taiwan,China.The epicenter area,determined by seismic data,lies in a region bounded by Chaochou and Chishan faults.The co-seismic surface deformation of the region is extracted using Sentinel-1A radar data based on differential interferometry.We get reliable co-seismic displacement fields compared with GPS data.InSAR-derived displacement field shows that there is an uplift zone along line-of-sight of about 30 km diameter,located at about 15 km west of the epicenter with a maximum displacement of about 12 cm.There is no apparent rupture around the macro-epicenter from the spatial distribution of displacement.The InSAR application of determining the macro-epicenter quickly shows the scientific significance of relief supplies and rapid assessment after earthquake.%利用欧洲航天局最新发射的宽刈幅、高分辨率Sentinel-1A卫星,第一时间获取2016-02-06台湾美浓Mw6.4地震干涉像对,使用I-InSAR技术获取美浓地区的同震形变场.利用震中附近39个同震GPS观测进行对比验证后显示,InSAR获取的同震形变场精度优于1 cm(3σ).形变发生在宏观震中30 km×30 km范围内,主要表现为沿雷达视线向抬升,最大抬升约12 cm.从形变场空间分布特征可以看出,空间连续性较好,说明宏观震中附近地表未发生明显破裂.宏观震中并不与震中位置重合,而是位于震中西部约15 km处.