GÄNDER (VS)

Active rock glacier

Elevation: 2420-2740m - Massif: Valais Alps (Mischabel) - Commune: Randa (VS)

The Gänder rock glacier, located on the orographic right side of the Mattertal is one of five rock glaciers that were found to be destabilized in the mid-2000s using satellite interferometry (InSAR). Its terminal part is destabilized at least since the 1970’s (development of scarps and velocities > 2m/y). However, only part of this destabilized section furnishes rock debris into a tributary channel of the Wildibach torrent. The destabilized part (between about 2500 and 2640 m a.s.l.) has moved at relatively constant velocities since the 1970’s. The front part is decelerating gradually since 2012. The first displacement measurements (DGPS) have been started there in 2009.

• Measurements and observations

  Geodetic (GNSS)
  Geophysics (geoelectric, refraction seismic)
  Remote Sensing (Webcam 2011-2013, aerial image)

• Figures

  

  Measured horizontal flow field (mean annual velocity).

   

   

  

  Annual horizontal surface velocity. Mean of a set of points selected in the most active part of the rock glacier. Annual survey interval

   

   

• Collaboration

  Gemeinde Randa

  Kanton Wallis – Dienststelle für Wald, Flussbau und Landschaft (DWFL)

• Publications

  Delaloye, R., Morard, S., Barboux, C.,  Abbet, D.,  Gruber, V., Riedo, M. and Gachet, S. (2013). Rapidly moving rock glaciers in Mattertal. In: Graf, C. (ed.) Mattertal – ein Tal in Bewegung. Publikation zur Jahrestagung der Schweizerischen Geomorphologischen Gesellschaft 29. Juni – 1. Juli 2011, St. Niklaus. Birmensdorf, Eidg. Forschungsanstalt WSL. 21-30. (pdf)