Kinematics at the Muragl rock glacier in Switzerland

To determine the influence of climate warming on permafrost, creep velocities of rock glaciers are a reliable measure, as they indirectly reflect the thermal conditions of a rock glacier. In this study, the kinematic and morphological characteristics of Muragl rock glacier in Switzerland were investigated using UAV images from 2015 and 2022, and correlations to changing ground surface and air temperatures over the same period were examined. Data collection was performed using repeated UAV surveys, annual terrestrial surveying, and continuous logging of ground surface temperatures. The collected data sets from the different methods were compared and tested for similar patterns in the rock glacier kinematics. The comparison of the UAV surveys and the terrestrial measurements showed heterogeneous patterns of the landform and agree with previous investigations. The central part of the rock glacier and the northern outburst lobe show higher velocities than the rest of the landform. Locally, creep velocities of up to 13.61m in seven years were calculated and the mass movements in the model of the creep behavior displayed surface changes up to 4m. The velocities of the individual years showed correlations with the average temperature measured in Switzerland. The change of the creep velocity during the mild and snow-poor winter of 2019/2020 was particularly recognizable. Furthermore, the creep velocities at Muragl rock glacier are relatively high in comparison to other rock glaciers in the region. Additionally, correlations between rising average temperatures in Switzerland, ground surface temperatures and the creep velocity at the Muragl rock glacier were clearly recognizable. The results of this study are advantageous to describe sensitivies of the cryosphere.