Morphology and surficial sediments of the Waldemar River confined outwash fan (Kaffiøyra, Svalbard)

Abstract

Abstract. The development and evolution of confined outwash fans in high Arctic regions depend on the rate of meltwater discharge, which is directly related to the glacier ablation rate, in turnassociated with climate conditions. Other factors controlling outwash fan morphology (e.g. depth and width of distributive channels) are processes of fluvial erosion, and the transport and deposition of sediments. These factors have not previously been considered together in relation to the evolution of the confined outwash fans which are commonly incised into the top of permafrost in the forefields of subpolar glaciers and in mountains in high Arctic regions. Morphology and surficial sediments of a confined outwash fan of the Waldemar River (NW Spitsbergen, Svalbard) were analysed on the basis of geomorphological and sedimentological studies. The results of our investigations show multiple relations between the depth and width of distributary channels, fan slope and textural features of glaciofluvial surficial sediments supplied into the fluvial system from the glacier and from lateral fluvial erosion of permafrost Morphology and surficial sediments of the Waldemar River confined outwash fan (Kaffiøyra, Svalbard)

Assessment of periglacial response to increased runoff: An Arctic hydrosystem bears witness

“…Note that even by considering a longer river bed due to the glacial retreat, the overall surface grew much wider over a 6-year (2010-2016) than in a 15-year (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) period. Furthermore, this significant amount of sediments is toppled over the catchment, combined with sediments from tundra erosion (in the foreland of the glacier marginal zone) as mentioned by Weckwerth and Sobota (2017). These processes are thus actively involved in the coastal dynamics such as progradation described by Bourriquen et al (2016).…”

Where will widening occur in an outwash braidplain? A new approach to detecting controls on fluvial lateral erosion in a glacierized catchment (north‐western Spitsbergen, Svalbard)

“…The width of the proximal part of the Waldemar River outwash braidplain varies from 70 m to 360 m (Figure 4), while the width of middle outwash increases from 360 m to 950 m, and the width of the distal part decreases from 950 m to 90 m (Figures 2 and 4). The morphology and surface sediments of the Waldemar River outwash were described and analysed in detail by Weckwerth et al (2017. The findings indicate that the proximal part of the outwash surface is dominated by inactive channels characterized by the most changeable and highest bankfull depths and widths, as compared to the middle and distal parts of the Waldemar River outwash (Figures 3 and 5).…”

“…F I G U R E 4 Downstream variation in braidplain slope (after Weckwerth et al, 2017 and width of proximal, middle and distal parts of the Waldemar River outwash (a) and transverse profiles in its proximal (b), middle (c) and distal (d) parts (see profile location in Figures 2 and 10D) Changes in air temperature and precipitation totals affect the mass balance of the glaciers, which leads to changes in river discharge, influencing fluvial activity in the forefields of contemporary glaciers (Costard et al, 2003;Lotsari et al, 2019;Strzelecki et al, 2018). Many years' worth of research in the catchment of the Waldemar River provides an important contribution to the understanding of fluvial processes (including lateral erosion) taking place in the river catchment (Sobota, 2005(Sobota, , 2014.…”

“…This reduces accommodation space for an active braidplain and is manifested in decreasing F I G U R E 1 3 Zones prone to active braidplain expansion (1-3) due to crossing the thresholds (T1(S), T2(S), T3(d 50 ), T4(d 50 )) in passive factors controlling braidplain widening in combination with braidplain slope changes (a) and spatial variation in median grain diameter of surficial sediments (b). Spatial variation in median grain diameter after Weckwerth et al (2017) [Colour figure can be viewed at wileyonlinelibrary.com] sediment sorting and surface sediments coarsening independently of the lowest braidplain slope (Figures 4,6 and 12c). The coarse grains that appear as a result of lateral erosion can be set in motion more easily on a channel bed composed of finer grains (Lamb et al, 2008;Solari & Parker, 2000).…”

“…This can also be helpful in refining locations for measuring the intensity of streambank erosion, especially in terms of long-term changes in braidplain width (Kociuba & Janicki, 2018;Palmer et al, 2014). Additionally, in proglacial setting the role of groundwater seeping and permafrost spatial distribution and dynamics of its active layer can also be considered (Carrivick & Heckmann, 2017;Costard et al, 2003;Kasprzak et al, 2017;Midgley et al, 2013;Outhet, 1974;Strzelecki et al, 2018;Walker et al, 1987;Walker & Arnborg, 1966;Weckwerth & Pisarska-Jamroży, 2015;Weckwerth et al, 2017 because its degradation due to fluvial and thermal erosion affects the transformation of landforms in glacierized catchments.…”