Abstract
Abstract. Permafrost as a climate-sensitive parameter and its occurrence and distribution play an important role in the observation of global warming. However, field-based permafrost distribution data and information on the subsurface ice content in the large area of the southern mountainous Tibetan Plateau (TP) are very sparse. Existing models based on boreholes and remote sensing approaches suggest permafrost probabilities for most of the Tibetan mountain ranges. Field data to validate permafrost models are generally lacking because access to the mountain regions in extreme altitudes is limited. The study provides geomorphological and geophysical field data from a north-orientated high-altitude catchment in the western Nyainqêntanglha Range. A multi-method approach combines (A) geomorphological mapping, (B) electrical resistivity tomography (ERT) to identify subsurface ice occurrence and (C) interferometric synthetic aperture radar (InSAR) analysis to derive multi-annual creeping rates. The combination of the resulting data allows an assessment of the lower occurrence of permafrost in a range of 5350 and 5500 m above sea level (a.s.l.) in the Qugaqie basin. Periglacial landforms such as rock glaciers and protalus ramparts are located in the periglacial zone from 5300–5600 m a.s.l. The altitudinal periglacial landform distribution is supported by ERT data detecting ice-rich permafrost in a rock glacier at 5500 m a.s.l. and ice lenses around the rock glacier (5450 m a.s.l.). The highest multiannual creeping rates up to 150 mm yr−1 are typically observed on these rock glaciers. This study closes the gap of unknown state of periglacial features and potential permafrost occurrence in a high-elevated basin in the western Nyainqêntanglha Range (Tibetan Plateau).
Highlights
Information on permafrost distribution is of great importance in times of global warming, especially in high-mountain areas (Hock et al, 2019), because these areas are climatically sensitive (Barsch, 1996; Mollaret et al, 2019)
The spatial heterogeneity of our data and of topographic variations in permafrost occurrence prevents us from providing precise elevational limits; we provide an assessment of probable occurrence of permafrost in a range according to the findings of the three methods
By using the electrical resistivity tomography (ERT) method we found ice-poor permafrost in ice lenses in mineral soils next to the rock glacier that corroborates the idea of permafrost conditions outside of blocky material at an elevation of 5450 m a.s.l
Summary
Information on permafrost (defined as a thermal state of perennially cryotic ground, frozen for at least 2 consecutive years; Ballantyne, 2018; Washburn, 1979) distribution is of great importance in times of global warming, especially in high-mountain areas (Hock et al, 2019), because these areas are climatically sensitive (Barsch, 1996; Mollaret et al, 2019). If permafrost as perennial frozen ground ice is available, periglacial landforms are well suited to detect and to study changes of permafrost and the related ice content (Kneisel and Kääb, 2007; Kääb, 2013, Knight et al, 2019). These changes have an increasing impact on people and their livelihood (Gruber et al, 2017), e.g., due to the importance of long-term ground ice as a water resource (Jones et al, 2019) in arid/semiarid regions like the Andes (Azócar and Brenning, 2010; Rangecroft et al, 2016) or the Tien Shan (Bolch and Marchenko, 2006). The scientific and social importance leads to a stronger focus on permafrost areas, especially on the Tibetan Plateau (TP) where permafrost conditions react fast to atmospheric warming (Cheng and Wu, 2007; Lu et al, 2017)
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
