Quantification of strain rate in the Western Alps using geodesy: comparisons with seismotectonics - Archive ouverte HAL Access content directly
Journal Articles Swiss Journal of Geosciences Year : 2008

Quantification of strain rate in the Western Alps using geodesy: comparisons with seismotectonics

(1) , (2) , (3) , (4) , (1) , (1)
1
2
3
4

Abstract

The contrasted seismotectonic regime of the Western Alps is characterized by radial extension in the high chain, combined with local compressive areas at the foothill of the belt, and everywhere occurrence of transcurrent tectonics. Here, we compare this seismotectonic regime to a large-scale compilation of GPS measurements in the Western Alpine realm. Our analysis is based on the raw GPS database, which give the measured velocity field with respect to the so called “stable Europe”, and an interpolated velocity field, in order to smooth the database on a more regular mesh. Both strain rate and rotational components of the deformation are investigated. The strain rate field shows patch-like structure, with extensional areas located in the core and to the North of the belt and compressional areas located in its periphery. Although the GPS deformation fields (both raw and interpolated) are more spatially variable than the seismotectonic field, a good qualitative correlation is established with the seismotectonic regionalization of the deformation. The rotation rate fields (both raw and interpolated) present counterclockwise rotations in the innermost part of the belt and a surprising continuous zone of clockwise rotations following the arc-shape geometry of the Western Alps along their external border. We interpret this new result in term of a counterclockwise rotation of the Apulia plate with respect to the stable Europe. This tectonic scheme may induce clockwise rotations of crustal block along the large strike-slip fault system, which runs in the outer part of the belt, from the Rhône-Simplon fault to the Belledonne fault and Southeastward, to the High-Durance and Argentera fault
Fichier principal
Vignette du fichier
Delacou2008_Article_QuantificationOfStrainRateInTh.pdf (1.25 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-00338714 , version 1 (27-11-2021)

Licence

Attribution - CC BY 4.0

Identifiers

Cite

Bastien Delacou, Christian Sue, Jean-Mathieu Nocquet, Jean-Daniel Champagnac, Cécile Allanic, et al.. Quantification of strain rate in the Western Alps using geodesy: comparisons with seismotectonics. Swiss Journal of Geosciences, 2008, 101 (2), pp.377-385. ⟨10.1007/s00015-008-1271-3⟩. ⟨insu-00338714⟩
203 View
16 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More