Finite fault inversion of DInSAR coseismic displacement of the 2009 L’Aquila earthquake (central Italy)

We define the geometric and kinematic characteristics
of the fault activated during the Mw = 6.3, 6 April 2009
L’Aquila earthquake, from the modeling of Envisat and
COSMO-SkyMed (the first ever X-band interferogram
inverted for a coseismic dislocation study) DInSAR
interferograms. Our best-fit solution for the main shock is
represented by a normal fault 16 km long and 12 km wide,
with a small right-lateral component, dipping 47 SW with a
maximum slip of 90 cm. Although the seismic dislocation
probably ended at 1km depth, the updip projection of the fault
plane corresponds to the northern segment of the mapped
Paganica–S. Demetrio fault, where alignment of surface
breaks was observed in the field. The absence of this fault in
existing seismic source catalogues suggests that an improved
approach, involving detailed surface and subsurface
geological and geophysical investigations, is needed for
a better assessment of the seismic hazard at the local
scale.

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