Study of the Dissimilar Deformation of Huxian, Near the Qinling Piedmont Fault (China), by Multiband InSAR Time-Series Technology

In recent years, small earthquakes around Huxian, near the Qinling Piedmont Fault (China), have attracted much attention from the local government. Due to the blindness to the characteristics of Huxian ground deformation, it is highly desirable to conduct ground deformation surveys in this area, as well as study the relationship between ground deformation and these earthquakes. To understand the surface-deformation characteristics of Huxian and the seismic background better, InSAR time-series processing was applied to C-, L-, and X-band SAR images of Huxian. InSAR results show that the surface motion was uplifting from 2007 to 2010, and the surface motion subsided from 2014 to 2015. The 2-dimensional deformation rate field from 2007 to 2010 was obtained by using ascending L-band images and descending C-band images. Models in elastic half-space were used to invert the depth of the surface-deformation power source, the results of which are less than 2.0km below the ground surface. The inversion results were compared with the available seismic records. Possible reasons for the surface deformation are discussed. According to our study, the observed movement has weak correlation with earthquakes even though the small earthquake activity in this area increased suddenly during recent years.