Proglacial icings as records of winter hydrological processes

Abstract

Abstract. The ongoing warming of cold regions is affecting hydrological processes, causing deep changes, such as a ubiquitous increase in river winter discharges. The drivers of this increase are not yet fully identified mainly due to the lack of observations and field measurements in cold and remote environments. In order to provide new insights into the sources generating winter runoff, the present study explores the possibility of extracting information from icings that form over the winter and are often still present early in the summer. Primary sources detection was performed using time-lapse camera images of icings found in both proglacial fields and upper alpine meadows in June 2016 in two subarctic glacierized catchments in the upper part of the Duke watershed in the St. Elias Mountains, Yukon. As images alone are not sufficient to entirely cover a large and hydrologically complex area, we explore the possibility of compensating for that limit by using four supplementary methods based on natural tracers: (a) stable water isotopes, (b) water ionic content, (c) dissolved organic carbon, and (d) cryogenic precipitates. The interpretation of the combined results shows a complex hydrological system where multiple sources contribute to icing growth over the studied winter. Glaciers of all sizes, directly or through the aquifer, represent the major parent water source for icing formation in the studied proglacial areas. Groundwater-fed hillslope tributaries, possibly connected to suprapermafrost layers, make up the other detectable sources in icing remnants. If similar results are confirmed in other cold regions, they would together support a multi-causal hypothesis for a general increase in winter discharge in glacierized catchments. More generally, this study shows the potential of using icing formations as a new, barely explored source of information on cold region winter hydrological processes that can contribute to overcoming the paucity of observations in these regions.

Guidelines for cold‐regions groundwater numerical modeling

“…Groundwater processes in permafrost environments are also of great importance for northern infrastructure (McKenzie et al, 2020), as heat advection may accelerate thawing and environmental changes. As examples, cryohydrogeology is important for thawing under road embankments (Chen, Fortier, McKenzie, & Sliger, 2020) and the formation of aufeis (or icing) (Chesnokova, Baraër & Bouchard, 2020; Ensom et al, 2020). Permafrost thaw and groundwater flow also affects mining development in northern regions, leading potentially to increased dewatering and contaminant transport in mine tailings storage systems (Elberling, 2004; Journeaux Associates, 2012).…”

Shallow and deep groundwater moderate methane dynamics in a high Arctic glacial catchment

“…Winter baseflows, which are related to hydrologic systems that are active year-round, are increasing in response to climactic changes in glacierized (Walvoord and Striegl, 2007;Liljedahl et al, 2017;Chesnokova et al, 2020a) and non-glacierized (Lammers et al, 2001;Smith et al, 2007;St. Jacques and Sauchyn, 2009;Danilovich et al, 2019;Makarieva et al, 2019) catchments across the Arctic and subarctic.…”

Groundwater springs formed during glacial retreat are a large source of methane in the high Arctic

“…This creates and maintains a talik (an unfrozen volume of water-saturated sediments) at the surface that can be sustained for many years. Proglacial icings are common on Svalbard 18,19 and are found in other glaciated regions of the Arctic and sub-Arctic 17,20,21 .…”