X- and C-Band SAR Surface Displacement for the 2013 Lunigiana Earthquake (Northern Italy): A Breached Relay Ramp?

Author

Stramondo, Salvatore ; Vannoli, Paola ; Cannelli, Valentina ; Polcari, Marco ; Melini, Daniele ; Samsonov, Sergey ; Moro, Marco ; Bignami, Christian ; Saroli, Michele

Author_Institution

Ist. Naz. di Geofisica e Vulcanologia, Rome, Italy

Volume

7

Issue

7

fYear

2014

fDate

Jul-14

Firstpage

2746

Lastpage

2753

Abstract

In this paper, we applied the differential interferometric synthetic aperture radar (DInSAR) technique to investigate and measure surface displacements due to the M_w 5.3 (M₁ 5.2), June 21, 2013 earthquake, occurred north of the Apuan Alps (NW Italy), in the discontinuity zone between the Lunigiana and Garfagnana area. Two differential interferograms showing the coseismic displacement have been generated using X-band and C-band data, taken from COSMO-SkyMed and RADARSAT-2 satellites, respectively. Both interferograms highlighted a clear pattern of subsidence of few cm located between the Lunigiana and Garfagnana basins. We then modeled the observed SAR deformation fields using the Okada analytical formulation and found them to be consistent with an extensional fault plane dipping toward NW at about 50 . The integrated analysis of DInSAR, geological data, modeling, and historical seismicity suggest that the fault responsible for the June 2013 earthquake corresponds to a breached relay ramp connecting the Lunigiana and Garfagnana seismogenic sources.

Keywords

earthquakes; faulting; geomorphology; geophysical techniques; radar interferometry; synthetic aperture radar; AD 2013; Apuan Alps; C-band SAR surface displacement; COSMO-SkyMed and RADARSAT-2 satellites; DInSAR technique; Garfagnana area; Lunigiana Earthquake; Lunigiana area; NW Italy; Northern Italy; Okada analytical formulation; X-band SAR surface displacement; breached relay ramp; coseismic displacement; differential interferograms; differential interferometric synthetic aperture radar; discontinuity zone; extensional fault plane; geological data; historical seismicity; integrated analysis; seismogenic sources; surface displacements; Deformable models; Earthquakes; Interferometry; Satellites; Surface topography; Synthetic aperture radar; Earthquakes; inversion modeling; normal fault; relay ramp; remote sensing; seismogenic source; surface displacement;

fLanguage

English

Journal_Title

Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of

Publisher

ieee

ISSN

1939-1404

Type

jour

DOI

10.1109/JSTARS.2014.2313640

Filename

6819006