Deformation in the Jura Mountains (France): First results from semi-permanent GPS measurements

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05/05/2006

Walpersdorf, A.(a), Baize, S.(b) , Calais, E.(c) , Tregoning, P.(d), Nocquet, J.-M.(e)
Earth and Planetary Science Letters
Volume 245, Issue 1-2, 15 May 2006, Pages 365-372

Type de document > *Article de revue
Mots clés publication scientifique > géologie , GPS , séismes
Unité de recherche > IRSN/DEI/SARG/BERSSIN
Auteurs > BAIZE Stéphane

New GPS estimates of relative motion across the Jura Mountain Belt with respect to the Eurasian Plate indicate less than 1 mm/yr of convergence, considerably less than previous estimates. Velocity uncertainties have been evaluated by several methods and range from 0.2 to 0.5 mm/yr for the semi-permanent stations. The major, statistically-significant strain feature inferred by the Jura GPS measurements is along-arc extension, compatible with tectonic studies. That the detected deformation is small in magnitude highlights two important issues: previous estimates are over-stated and that the approach of using semi-permanent GPS installations is capable of detecting small tectonic signals. Using the upper bound as the rate of convergence, we estimate that this would generate an earthquake of magnitude 5-5.5 every 15 to 75 yr.

a- Laboratoire de Géophysique Interne et Tectonophysique, Joseph Fourier University, Maison des Géosciences, BP 53, 38041 Grenoble Cedex 9, France
b- IRSN-Seismic Hazard Division, France
c- Purdue University, West Lafayette, IN, United States
d- Research School of Earth Sciences, The Australian National University, Canberra, Australia
e- Géosciences Azur, Valbonne, France