Abstract
In Western Europe, the Western Alps is one of the most seismically active regions with a large density of earthquakes and some historical damaging earthquakes. There is no consensus on the driver of seismicity in the region, although the African-Eurasian tectonic convergence hypothesis is not consistent with the seismic extension in the inner part of the Alps. The last decade's improvement of GNSS coverage allows a sufficient resolution on strain rate map to point out deformation of 10-9 yr-1, necessary to study active processes in low deformation region. With the final goal to study surface processes as a driver of seismicity, the objective of this study is to give a robust strain rate map of the Western Alps. We used three datasets processed independently (two velocity fields communicated; one velocity field computed from available position time series in this study) to identify common signals. The precise comparison between datasets confirms the radial extension rate in the inner part of the Alps. The strain rate map computed in this study shows significant deformation, that could be linked with surface processes and micro-plate rotation.