Abstract
Abstract. Rock glaciers are typical periglacial landforms. They can indicate the existence of permafrost, and can also shed light on the regional geomorphological and climatic conditions under which they may have developed. This article provides the first rock glacier inventory of Daxue Shan, south-eastern Tibetan Plateau. The inventory is based on analyses of Google Earth imagery. In total, 295 rock glaciers were identified in Daxue Shan, covering a total area of 55.70 km2 between the altitudes of 4300 and 4600 m above sea level. Supported by ArcGIS and SPSS software programmes, we extracted and calculated morphometric parameters of these rock glaciers, and analysed the characteristics of their spatial distribution within Daxue Shan. Our inventory suggests that the lower altitudinal boundary for permafrost across the eight aspects of observed slopes differs significantly and that the lower altitudinal permafrost boundary is ∼ 104 m higher on western than eastern-facing slopes. Moraine-type and talus-derived rock glaciers exhibit mean gradients that are all concentrated within the 22–35∘ range. However, lobate rock glaciers (27–45∘) have a higher mean gradient than tongue-shaped rock glaciers (22–35∘). Shady (i.e. N, NE, and E) slopes appear related to the presence of moraine-type rock glaciers, whereas sunny (i.e. W, SW, and S) slopes appear related to the presence of talus-derived rock glaciers. Rock glaciers in Daxue Shan are more concentrated within tertiary monzonitic granite, which is more sensitive than other lithological components to the freeze–thaw process. Continuous weathering of this substrate provides the ideal raw material for the rock glacier development. These results show that environmental controls (i.e. topographical, climatic, lithological factors) greatly affect the formation and development of rock glaciers. This study provides important data for exploring the relation between maritime periglacial environments and the development of rock glaciers on the south-eastern Tibetan Plateau (TP). It may also highlight the characteristics typical of rock glaciers found in a maritime setting.
Highlights
The term “rock glacier” was first proposed by the American scholar Capps (1910) when investigating Kennicott Glacier in Alaska
Tongueshaped rock glaciers have slopes with mean gradients which are concentrated in the 22–35◦ range, whereas those of lobate rock glaciers fall within the 27–45◦ range
The altitudes of the mountains and rock glacier lengths increase with latitude, whereas air temperatures decrease, which implies that the northern sector of Daxue Shan has an environment that is more conducive to the formation of rock glaciers and other periglacial landforms
Summary
The term “rock glacier” was first proposed by the American scholar Capps (1910) when investigating Kennicott Glacier in Alaska. Rock glaciers consist of perennially frozen masses of ice and debris that creep downslope under the weight of gravity (Haeberli, 1985; Barsch, 1996; Haeberli et al, 2006). The bodies of rock glaciers are similar to moraines in that, as their ice mass moves over a pore ice surface, they do not sort materials in relation to the thickness of the debris they contain. There are ∼ 73 000 rock glaciers globally (Jones et al, 2018a), with ∼ 1000 active rock glaciers in the Swiss Alps alone. The freeze–thaw process experienced by the ice masses within rock glaciers can exert a major impact on the hydrological cycle (Azócar and Brenning, 2010; Jones et al, 2018a, b), and creep of rock glaciers can significantly negatively influence any infrastructure built on top.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
