Eos, Transactions American Geophysical Union

Global Positioning System Network monitors the western Alps


  • J. Chéry,

  • C. Vigny,

  • B. Meyer,

  • G. Ferhat,

  • M. Anzidei,

  • R. Bayer,

  • L. Boloh,

  • P. Briole,

  • A. Deschamps,

  • K. L. Feigl,

  • J. F. Gamond,

  • A. Geiger,

  • F. Jouanne,

  • M. Kasser,

  • M. Lepape,

  • J. Martinod,

  • G. Ménard,

  • J. C. Ruegg,

  • J. M. Scheubel,

  • J. J. Walch


A high-precision GPS network was installed in the Western Alps in September 1993 to map the movement of the African and Eurasian plates in the Mediterranean region. The GPS measurements will explain how convergence is distributed in the Western Alps, the largest, highest, and most deformed range in the Alpine collision zone. If a large earthquake strikes the region, the network will also help constrain the dislocation at depth.

Measurements of convergence will be made every five years. Global plate motion models predict a north-south mean convergence rate of 6 mm/yr between the African and Eurasian plates in the Western Mediterranean region (Figure lb). Most of this deformation is probably accommodated in the active mountain belts: the Pyrenees, Alps, Apennines, and Maghrebids. Deformation in these structures is complex.