THE DEFORMATION MEASUREMENT OF THE LAOHUSHAN FAULT BASED ON THE FRAM-SBAS METHOD

摘要

Haiyuan fault zone (in board sense) is located in the west of China, which is not only the important activity block boundary tectonic belt, but also an important strong earthquake activity belt.The Ms8.5 Haiyuan earthquake occurred in that fault zone in 1920. Studying the fracture activity and the seismic risk is meaningful and necessary.Scholars had made a lot research on the activity rate of the Haiyuan fault zone. However, most of their results are calculated by sparse discrete points, which is different with the observation location and the density of the point [1]. In resent years，the InSAR technology based on time series analyses to many SAR images has been used for measurement of interseismic deformation along active fault, such as Stacking, PSI and SBAS.In this paper, we use a promoted SBAS method called FRAM-SBAS to calculate the deformation velocity of the Laohushan fault, which is part of the Haiyuan fault zone (in board sense). The data of the InSAR time series analysis is during the period from September 2008 to August 2009 using 7 senses of ASAR images. The deformation velocity of the Laohushan fault is about -2～10mm/yr according to our calculation. At the same time the Laohushan fault has a different velocity in different part, so we segment the fault into 4 parts due to the deformation velocity.