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

Abstract : 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.