Deglaciation patterns in the Upper Zemmgrund, Austria: An exploration of clean-ice disintegration scenarios

The European Alps are rapidly losing glacier mass due to climatic warming and are anticipated to be largely ice-free by the year 2100. Long-term glacier monitoring in the Alps provides a record of anthropogenically-driven climate change since the Little Ice Age maximum in ~1850. Understanding these long-term glacier changes provides a basis for mitigating hazards (e.g., mass movements) associated with a transition to a paraglacial environment and for predicting future scenarios. Here, we present a post-Little Ice Age-maximum record of glacial landscape changes in the Upper Zemmgrund, Austria, utilising a multi-method framework integrating multi-decadal geomorphological mapping, historical imagery and remote sensing of glacier change. This study contributes a high-resolution, quantifiable record of the transition from a glacial to paraglacial landscape. We find that individual glacier response to climatic change varies within the Upper Zemmgrund, attributed to glacier characteristics such as hypsometry and size. Nonetheless, all glaciers show signs of growing instability such as an increase in crevasses and the collapse of circular tension structures, which have dammed meltwater at the terminus of one glacier, posing a substantial hazard to downstream communities. Future glacier disintegration is anticipated to accelerate in the Upper Zemmgrund, which may result in an ice-free landscape within the next ~40–60 years.