Contribution of real-time kinematic GPS in the study of creeping mountain permafrost: Examples from the Western Swiss Alps

The use of real-time kinematic (RTK) GPS for studying the dynamics of creeping mountain permafrost is evaluated on the basis of measurements carried out on three test sites in the Western Swiss Alps. The high precision of the method and its ease of use make the RTK GPS appropriate for this kind of study. A wide range of information can be obtained by comparing the position of a set of surveyed points after two campaigns of measurement: determination of both horizontal and vertical components of surface movements, identification of compression and extension zones, estimation of thickness variation and, finally, determination of three-dimensional (3D) rotational movements of individual boulders. Temporal variations of all these parameters can then be identified after more than two repetitions of the measurement series. The results obtained on the test sites are presented and discussed from a geomorphological point of view. They were sometimes surprising, for instance the strong difference in surface velocities of two morphologically similar rock glaciers situated in the same area or the small 3D rotation of blocks located on the front of a rapidly moving rock glacier. Copyright (C) 2004 John Wiley Sons, Ltd.