Mechanism of deformation around northern Hejin, China, observed by InSAR

:Interierometric synthetic aperture radar (InSAR) images reveal deformation around northern Hejin, Shanxi Province. The small baseline subset (SBAS) approach for InSAR-derived deformation indicates that the observed deformation pattern can be characterized by the sum of two phenomena: background subsidence from December 2003 to February 2009 with a cumulative displacement of approximately 5 cm and uplift from February 2009 to November 2010 with a cumulative displacement of approximately 2. 5 cm. Deformation modeling indicates that the local deformation was caused by the closing and opening of a sill beneath northern Hejin. The modeled sill which is approximately 5 km long, 2 km wide, is centered at 1. 5 km depth. The deformation was caused by the withdrawal and influx of subsurface water.