Comment on “Surface deformation caused by April 6th 2009 earthquake in L’Aquila (Italy): A comparative analysis from ENVISAT ASAR, ALOS PALSAR and ASTER” by M.A. Goudarzi, T. Woldai, V.A. Tolpekin

The present work concerns some observations about the paper by Goudarzi et al. (2011), related to the
surface deformation analysis carried out for the earthquake that hit the city of L’Aquila, Italy, on April
2009 and based on SAR Differential Interferometry (DInSAR) technique.
We have manly identified a criticality about the post-seismic deformation, named by the author postseismic
relaxation. The analysis performed by Goudarzi et al. (2011) leads to misleading conclusions in
terms of seismic hazard all over the epicentral region. Here, some considerations driven by literature
and interferograms comparison demonstrate the incorrectness of their interpretation concerning the
coseismic and post seismic surface deformation.