Abstract ID: 28.7413 | Accepted as Poster | Poster | 2025-02-28 12:45 - 14:15 | Ágnes‐Heller‐Haus/Small Lecture Room

High temporal resolution monitoring of Alpine glacier dynamics provides essential insights into the glacier’s flow processes. At Hintereisferner in the Ötztal Alps (Austria) an ablation stake – the “ice lollipop” – was installed in 2020 and has been continuously monitored by an automated terrestrial laser scanning system until December 2022. This approach enables precise observations of horizontal and vertical flow and links the geodetic to the glaciological mass balance measurement at point scale.

The near-daily measurements over three hydrological years reveal a horizontal glacier flow of approximately 10 meters per year, with surface velocity increasing during the melt season. However, vertical motion patterns are more complex. In the melt season, the stake demonstrates a consistent downward trajectory, indicative of ice submergence. This is consistent with its location above a steep section of the glacier, where increased driving stress promotes extending flow and transverse crevasse formation. Conversely, a slight upward movement is observed in winter, consistent with emergence in the ablation zone.

These seasonal variations in the three-dimensional movement of Hintereisferner reflect the ice dynamics influenced by factors such as basal meltwater, bed separation, and bedrock irregularities. Further research, including multiple ice lollipops distributed over the glacier, is planned to learn more about these processes and their implications for the glacier’s behavior.