The Dösen Rock Glacier in Central Austria: A key site for multidisciplinary long-term rock glacier monitoring in the Eastern Alps

Abstract

Rock glaciers are distinct landforms in high mountain environments indicating present or past permafrost conditions. Active rock glaciers contain permafrost and creep slowly downslope often forming typical flow structures with ridges and furrows related to compressional forces. Rock glaciers are widespread landforms in the Austrian Alps (c. 4600). Despite the high number of rock glaciers in Austria, only few of them have been studied in detail in the past. One of the best studied ones is the 950 m long Dösen Rock Glacier located in the Hohe Tauern Range. This rock glacier has been investigated since 1993 using a whole suite of fieldbased and remote sensing-based methods. Research focused on permafrost conditions and distribution, surface kinematics, internal structure and possible age of the landform. Results indicate significant ground surface warming of the rock glacier body during the period 2007-2015 accompanied by a general acceleration of the rock glacier surface flow velocity (max. 0.66 m/a) over the last two decades. This speed-up is possibly related to higher ice temperature and water content. As judged from various geophysical measurements, the maximum thickness of the rock glacier is about 30-40 m with an active layer of several meters depending on the location. The permafrost thickness beneath the active layer was quantified to be between 10 m (at the margins) and 40 m (at the central and upper parts). Massive sedimentary ice has not been observed or detected by geophysics so far at the central and lower part but might exist to in the rooting zone of the rock glacier as indicated from field evidences. The Dösen Rock Glacier is primarily a talus-derived rock glacier although a small glacier might have existed some times in the past in the eastern part of the rooting zone. Age estimations of the rock glacier by using the Schmidt-hammer exposure-age dating method indicate a formation period of several thousand years with alternating periods of faster and slower evolution. Research findings at this typical alpine rock glacier in the Austrian Alps clearly point out that the morphogenesis, the internal structure as well as the climaterock glacier relationship is complex but typical for such peculiar alpine landforms.________________________________________

Pluri‐decadal evolution of rock glaciers surface velocity and its impact on sediment export rates towards high alpine torrents

“…In the European Alps, past and recent inventories allowed to evidence their abundance above roughly 2500 m of elevation (e.g., Kofler et al, 2020;Lambiel & Reynard, 2003;Marcer et al, 2017). Over the last two decades, rock glaciers velocity and its evolution through time have been investigated by numerous studies (e.g., Bodin et al, 2018;Delaloye et al, 2008;Kellerer-Pirklbauer et al, 2017;Lambiel & Delaloye, 2004;PERMOS, 2019). As a result, a clear accelerating trend of rock glaciers displacement rates could be underlined for most surveyed sites as a consequence of warming air temperatures inducing higher ground temperatures and liquid water content (e.g., Cicoira et al, 2019;Ikeda et al, 2008;Kellerer-Pirklbauer & Kaufmann, 2012;PERMOS, 2019;Roer et al, 2008;Seppi et al, 2019).…”

Rock Glacier Characteristics Under Semiarid Climate Conditions in the Western Nyainqêntanglha Range, Tibetan Plateau

“…In the context of climate change, glacial and periglacial landscapes are receiving increased attention as a water resource, especially in semiarid climates with growing population, for example, the Tibetan Plateau (Bolch et al., 2019; Hock et al., 2019; Immerzeel et al., 2020; Sun et al., 2018). Glacial and periglacial landforms are sensitive to climate warming and represent significant water reservoirs in semiarid environments and lowlands (Halla et al., 2021; Jones, Harrison, Anderson, & Betts, 2018; Jones, Harrison, Anderson, Selley, et al., 2018; Karjalainen et al., 2020; Kellerer‐Pirklbauer et al., 2017; Müller et al., 2016). In the western Nyainqêntanglha range on the Tibetan Plateau periglacial conditions and related landforms prevail (Anslan et al., 2020; Buckel et al., 2021; Keil et al., 2010; Reinosch et al., 2020).…”

“…The movement creates a lobate or tongue shaped landform with typical furrows and ridges (Janke & Frauenfelder, 2008). The lithologic composition and the resulting clast size of rock glaciers is indicative of its kinematics, activity and ice content (Barsch, 1996;Degenhardt, 2009;Kellerer-Pirklbauer et al, 2017). Although a widespread feature on the Tibetan Plateau Z.…”

Multi‐temporal 3D point cloud‐based quantification and analysis of geomorphological activity at an alpine rock glacier using airborne and terrestrial LiDAR

“…To support the interpretation of quantified surface changes, additional information on the distribution of resistivity values in the subsurface is derived from electrical resistivity tomography (ERT). Overall, this enables further insights into the internal conditions and the composition of the rock glacier . The integration of ERT and LiDAR has been shown to be highly valuable for understanding geomorphological processes in other fields of geoscientific application .…”

“…Overall, this enables further insights into the internal conditions and the composition of the rock glacier. 59 The integration of ERT and LiDAR has been shown to be highly valuable for understanding geomorphological processes in other fields of geoscientific application. 60,61 For surface changes of rock glaciers, only one study was found which combines airborne LiDAR and ERT.…”