The characteristics and formation of a High-Arctic proglacial icing

• Published in: Geografiska Annaler: Series A, Physical Geography
• Main Authors: Hodgkins, R, Tranter, M, Dowdeswell, JA
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2004
• Subjects: proglacial; icing; Aufeis; naled; hydraulic conductivity; SPITSBERGEN GLACIERS; SOLUTE ACQUISITION; SCOTT TURNERBREEN; MASS-BALANCE; SVALBARD; HYDROCHEMISTRY; MELTWATERS; HYDROLOGY; MODEL; FLOW; Arctic; Scott Turnerbreen; Svalbard; Arctic Archipelago; glacier; Ice; permafrost; Spitsbergen
• Online Access: https://pure.au.dk/portal/da/publications/the-characteristics-and-formation-of-a-higharctic-proglacial-icing(695e85eb-17ff-4754-a3d0-373e5477cb2e).html; https://doi.org/10.1111/j.0435-3676.2004.00230.x

Well-known from permafrost hydrology, icings (naled or Aufeis) are also frequently encountered at the margins of high-latitude glaciers. The morphology of a proglacial icing at Scott Turnerbreen in the Norwegian Arctic archipelago of Svalbard is described, and the process of formation is considered in detail. Ground thermal-regime modelling indicates an equilibrium permafrost depth of at least 200 m in the studied catchment, and it appears unlikely that groundwater contributes to icing formation. Meltwater flow through ice-marginal drainage channels is accompanied by estimated heat fluxes of up to about 190 W m(-2), suggesting that stored meltwater may continue to percolate through thawed sub-channel sediments when surface runoff is absent during winter. A hydraulic conductivity of 6.9 x 10(-3) m s(-1) is implied, which is consistent with other studies of glacier drainage systems. The long residence time of winter-draining meltwater, and solute rejection by refreezing water, account for high observed concentrations of solute in interstitial water in the icing. It has often been asserted that the presence of a proglacial icing indicates that a glacier is polythermal. However, as Scott Turnerbeen is entirely non-temperate, the presence of an icing cannot always be treated as a reliable guide to the thermal regime of a glacier.