Université de Fribourg

3D cartographic modeling of the Alpine Arc

Vouillamoz, Naomi ; Sue, Christian ; Champagnac, Jean-Daniel ; Philippe, Calcagno

In: Tectonophysics, 2012, p. -

We built a 3D cartography of the alpine arc, a highly non-cylindrical mountain belt, using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric line and the Crustal Penninic Front). It provides...

Université de Neuchâtel

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

Delacou, Bastien ; Sue, Christian ; Nocquet, Jean-Mathieu ; Champagnac, Jean-Daniel ; Allanic, Cécile ; Burkhard, Martin

In: Swiss Journal of Geosciences, 2008, vol. 101, no. 2, p. 377-385

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...

Université de Neuchâtel

Aseismic deformation in the Alps: GPS vs. seismic strain quantification

Sue, Christian ; Delacou, Bastien ; Champagnac, Jean-Daniel ; Allanic Cecile ; Burkhard, Martin

In: Terra Nova, 2007, vol. 19, no. 3, p. 182-188

Neotectonics of the Western and Central Alps is characterized by ongoing widespread extension in the highest zones of the chain and transcurrent/compressive tectonics at the external limits of the belt. The overall geodetically measured deformations also indicate extension across the Western Alps. There is a good qualitative coherency between seismotectonic and geodetic approaches. Here we...

Université de Neuchâtel

Origin of the current stress field in the western/central Alps : role of gravitational re-equilibration constrained by numerical modeling

Delacou, Bastien ; Sue, Christian ; Champagnac, Jean-Daniel ; Burkhard, Martin

In: Deformation Mechanisms, Rheology and Tectonics : from Minerals to the Lithosphere, 2005, vol. 243, p. 295-310

We interpret the strain and stress fields of the western / central Alpine arc on the basis of 2.5D finite element modelling and a recent seismotectonic synthesis. Models have fixed boundary forces and different crustal geometries, so that they respond to buoyancy forces (variations in gravitational potential energies). The seismotectonic regime, characterized by orogen-perpendicular extension in...

Université de Neuchâtel

Brittle orogen-parallel extension in the internal zones of the Swiss Alps (South Valais)

Champagnac, Jean-Daniel ; Sue, Christian ; Delacou, Bastien ; Burkhard, Martin

In: Eclogae Geologicae Helvetiae, 2003, vol. 96, p. 1-14

De nouvelles données de fracturation tardi-alpine dans le Sud Valais (Alpes Suisses) sont présentées ici. Nous avons utilisé différentes images satellites ainsi que le Modèle Numérique de Terrain (MNT) à 25m de résolution pour identifier et cartographier différentes structures morphologiques, linéaments ou escarpements de failles. Un contrôle sur le terrain nous a permis de...

Université de Neuchâtel

Active strike-slip faulting in the Chablais area (NW Alps) from earthquake focal mechanisms and relative locations

Delacou, Bastien ; Deichmann, Nicholas ; Sue, Christian ; Thouvenot, François ; Champagnac, Jean-Daniel ; Burkhard, Martin

In: Eclogae Geologicae Helvetiae, 2005, vol. 98, p. 189-199

La région du Chablais est caractérisée par une configuration géologique et structurale complexe, résultant de la mise en place de nappes de charriage de provenances variées (nappes Préalpines) chevauchantes sur les unités externes Helvétiques durant l’Oligocène. Alors que l’historique de la mise en place de ces nappes est bien compris, le régime tectonique actuel reste à définir....