Analysis of Deformation Process of the L'Aquila Earthquake Detected by PSInSAR

Using 8 descending track Envisat ASAR images,time series of different interferograms and consequent co-seismic deformation field of the L'Aquila earthquake(Mw 6.3 on 6 April 2009) were obtained by PSInSAR method.Furthermore,deformation processes of rupture zone were numerically analyzed using Delaunay triangulation algorithms based on above results.The results show that:① The rupture center located at a low elliptic depression region.The cracking propagated along southeastward direction with an orientation of 135° and covered about 22×14 km2.② The deformation area was mainly located in the rupture center,which was formed at the epoch of earthquake and thereafter.The displacement of rupture center in radar line of sight was as high as 150 mm.③ The numerical analysis results of the entire deformation process in rupture zone detected by Envisat show that: from Jan.2008 to Feb.2009 before the earthquake,the ground deformation of target zone was not significant;from Feb.to Apr.2009 after the shock,the deformation field of rupture zone changed rapidly with a maximum of subsidence of 130 mm;from Jun.to Jul.2009,the settling velocity of deformation field was slowing-down;while on 30 Aug.2009,the subsidence rate shown from last SAR image turns to accelerate,and total settlement amount in rupture zone reached 150 mm.