A unique record of rock glacier kinematics and glacier interactions spanning more than 100 years in the Swiss National Park

Alberto Muñoz-Torrero Manchado (Université de Genève) mit Simon Allen, Alessandro Cicoira, Ruedi Haller, Markus Stoffel

The rock glaciers of the Swiss National Park were the first globally upon which in-situ measurements of surface displacement were realized starting with the pioneering work of Chaix in 1918. This globally unique long-term record is a main reason why these rock glaciers have recently been included by UNESCO as one of the top 100 IUGS geological world heritage sites. With our work we have filled the gap previously existing between the measurements from the early 20th century and the most recent measurements made in the last two decades. Through the application of photogrammetry techniques, we use this unique record of more than 100 years to geomorphologically analyze the spatiotemporal evolution of rock glaciers in the region, but also the interplay with their contributing glaciers. We show that these rock glaciers are in different phases of degradation with a general trend of deceleration and loss of volume. We observe how the changes in kinematics seem to be historically controlled by the hydrological contribution of their nearby glaciers, with which they have been in close contact since the end of the LIA, but which are now severely degraded.