34 measurements A total of 55 measurement points have been surveyed twice a year since 2003 using differential real time kinematic (KTK) GIS on boch the Grabengufer rock glacier and the landslide. The GPS reference station was set up on a stable punt close to the rock glacier (Lambiel and Delaloye, 2004). The accuracy of one single measurement in horizontal components is usually better than 3 cm. mostly close to 1 cm. The accuracy in elevation is slightly higher. As two measurements are necessary for determining displacement rates the inaccuracy range of the KIK GPS technique is about 5 cm.