Surface deformation caused by April 6th 2009 earthquake in L’Aquila (Italy): A comparative analysis from ENVISAT ASAR, ALOS PALSAR and ASTER

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.…”

“…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.…”

“…The paper by Goudarzi et al (2011), focuses on a well known, widely studied, seismic sequence, where the analysis of the surface deformation has been treated with an unprecedented amount of satellite and in situ data. This implies that the seismogenic fault, the co-seismic displacement field, the post-seismic movements, the reactivation of gravitative deformations, have been investigated in detail.…”

“…The main criticality of the paper concerns the results in Goudarzi et al (2011) about the post-seismic deformation, which is named post-seismic relaxation by the authors. The considerations made by the authors about this phenomenon start from the comparison of the co-seismic interferograms they obtained from ALOS and ENVISAT images, with the one from Goudarzi et al (2011), hereafter named COSMO-Feb19-Apr09.…”

“…The considerations made by the authors about this phenomenon start from the comparison of the co-seismic interferograms they obtained from ALOS and ENVISAT images, with the one from Goudarzi et al (2011), hereafter named COSMO-Feb19-Apr09. In Goudarzi et al (2011) it is asserted that the COSMO-Feb19-Apr09 interferogram shows "that the co-seismic surface deformation was initially concentrated to the north of the main event epicentre along a line passing L'Aquila and Poggio Picenze". Stemming from the analysis of COSMO-Feb19-Apr09 interferogram (see Fig.…”