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Gravity-driven postseismic deformation following the Mw 6.3 2009 L’Aquila (Italy) earthquake
Author(s)
Language
English
Obiettivo Specifico
4T. Fisica dei terremoti e scenari cosismici
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/5(2015)
Electronic ISSN
2045-2322
Pages (printed)
16558
Issued date
November 10, 2015
Last version
http://www.nature.com/articles/srep16558
Abstract
The present work focuses on the postseismic deformation observed in the region of L’Aquila (central
Italy) following the Mw 6.3 earthquake that occurred on April 6, 2009. A new, 16-month-long dataset
of COSMO-SkyMed SAR images was analysed using the Persistent Scatterer Pairs interferometric
technique. The analysis revealed the existence of postseismic ground subsidence in the mountainous
rocky area of Mt Ocre ridge, contiguous to the sedimentary plain that experienced coseismic
subsidence. The postseismic subsidence was characterized by displacements of 10 to 35 mm along
the SAR line of sight. In the Mt Ocre ridge, widespread morphological elements associated with
gravitational spreading have been previously mapped. We tested the hypothesis that the postseismic
subsidence of the Mt Ocre ridge compensates the loss of equilibrium induced by the nearby coseismic
subsidence. Therefore, we simulated the coseismic and postseismic displacement fields via the finite
element method. We included the gravitational load and fault slip and accounted for the geometrical
and rheological characteristics of the area. We found that the elastoplastic behaviour of the material
under gravitational loading best explains the observed postseismic displacement. These findings
emphasize the role of gravity in the postseismic processes at the fault scale.
Italy) following the Mw 6.3 earthquake that occurred on April 6, 2009. A new, 16-month-long dataset
of COSMO-SkyMed SAR images was analysed using the Persistent Scatterer Pairs interferometric
technique. The analysis revealed the existence of postseismic ground subsidence in the mountainous
rocky area of Mt Ocre ridge, contiguous to the sedimentary plain that experienced coseismic
subsidence. The postseismic subsidence was characterized by displacements of 10 to 35 mm along
the SAR line of sight. In the Mt Ocre ridge, widespread morphological elements associated with
gravitational spreading have been previously mapped. We tested the hypothesis that the postseismic
subsidence of the Mt Ocre ridge compensates the loss of equilibrium induced by the nearby coseismic
subsidence. Therefore, we simulated the coseismic and postseismic displacement fields via the finite
element method. We included the gravitational load and fault slip and accounted for the geometrical
and rheological characteristics of the area. We found that the elastoplastic behaviour of the material
under gravitational loading best explains the observed postseismic displacement. These findings
emphasize the role of gravity in the postseismic processes at the fault scale.
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article
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