Postseismic deformation in South Iceland studied using multiple acquistion radar interferometry

Models of two different postseismic mechanisms, viscoelastic relaxation and afterslip, can both explain yearly GPS observations following two magnitude 6.5 earthquakes that occurred in South Iceland in 2000, as these models predict very similar horizontal displacements. However, the predicted vertical displacements of these models differ, and thus good information about the vertical displacements is needed to distinguish between these competing explanations. Within this project we attempt to retrieve information about the vertical deformation using persistent scatterer (PS) interferometric analysis with 32 ERS-2 SAR scenes of the area from 2000-2005. However, the results of the PS analysis were limited as the work was hampered by a typically low density of stable points in this rural farming area and by large Doppler centroids. More success was achieved by using a small baseline approach with ∼25 multilooked and filtered interferograms that were unwrapped and then used in time-series analyses.