Comparison of geomorphological field mapping and 2D‐InSAR mapping of periglacial landscape activity at Nordnesfjellet, northern Norway

Abstract

The ability to continuously monitor the dynamic response of periglacial landforms in a climate change context is of increasing scientific interest. Satellite radar interferometry provides information on surface displacement that can be related to periglacial processes. Here we present a comparison of two-dimensional (2D) surface displacement rates and geomorphological mapping at periglacial landform and sediment scale from the mountain Nordnesfjellet in northern Norway. Hence, 2D Interferometric Synthetic Aperture Radar (InSAR) results stem from a 2009-2014 TerraSAR-X dataset from ascending and descending orbits, decomposed into horizontal displacement vectors along an east-west plane, vertical displacement vectors and combined displacement velocity. Geomorphological mapping was carried out on aerial imagery and validated in the field. This detailed landform and sediment type mapping revealed an altitudinal distribution dominated by, weathered bedrock blockfields, surrounded primarily by slightly, to non-vegetated solifluction landforms at the mountain tops. Below, an active rockslide and associated rockfall deposits are located on the steep east-facing side of the study area, whereas glacial sediments dominate on the gentler western side. We show that 2D InSAR correctly depicts displacement rates that can be associated with typical deformation patterns for flat-lying or inclined landforms, within and below the regional permafrost limit, for both wet and dry areas. A net lowering of the entire landscape caused by general denudation of the periglacial landforms and sediments is here quantified for the first time using radar remote sensing.

Review of Works Combining GNSS and InSAR in Europe

“…A total of 14 nations have at least one reported application. The country with the highest number of contributions is Norway, represented by the cases of the Åknes landslide [114], the Gamanjunni rock slope [78], the Osmundneset landslide in Sognog Fjordane [115], the periglacial landscape activity at Nordnesfjellet [116], and the mapping [79] and monitoring [80] of landslides in North and West Norway. Norway is followed by Switzerland, with 6 contributions, including 3 peer reviewed articles in international journals and 3 proceedings, which focused on rock glacier detection and monitoring [117,118], slope instability monitoring events in the Western Alps [119,120], and deep-seated landslide recognition by Osco [121] and Aletsch Forest [122].…”

Structurally controlled rock slope deformation in northern Norway

“…The site has been continuously monitored from 2007, with installations of GNSS, laser, extensometers, ground-based radar (GB-InSAR), satellite corner reflectors, borehole instrumentation measuring displacement, water levels, temperature and vibrations (differential monitoring of stability, DMS), tiltmeters, meteorological station and web cameras (NVE 2019). The slide has been the subject of studies, investigations and theses since 1999 (Braathen et al 2004;Blikra et al 2006aBlikra et al , b, 2009Rønning et al 2008;Blikra and Longva 2009;Nordvik et al 2010;Ganerød 2013a, b;Skrede 2013;Elvebakk 2013Elvebakk , 2014Blikra and Christiansen 2014;Eriksen et al 2017a, b;Eckerstorfer et al 2018).…”

Insights in a remote cryosphere: A multi method approach to assess permafrost occurrence at the Qugaqie basin, western Nyainqêntanglha Range, Tibetan Plateau

“…We have used three different methods (A-C) to gain insights into permafrost-indicating periglacial landforms and to derive the lower occurrence of probable permafrost in the Qugaqie catchment ( Figure 2 (A) A geomorphological map visualizes the distribution and characteristics of landforms and geomorphometric features with the focus on periglacial landforms on a catchment-wide/regional scale. Periglacial landforms like rockglaciers (Barsch, 1996) and protalus ramparts (Scapozza, 2015) can potentially preserve ice over a long period of time (Ballantyne, 2018) and their activity and perennial creeping is an indicator for permafrost occurrence (Delaloye et al, 2010;Eckerstorfer et al, https://doi.org/10.5194/tc-2020-114 Preprint. Discussion started: 2 June 2020 c Author(s) 2020.…”