Dendritic subglacial drainage systems in cold glaciers formed by cut-and-closure processes

• Published in: Geografiska Annaler: Series A, Physical Geography
• Main Authors: Naegeli, Kathrin, Lovell, Harold, Zemp, Michael, Benn, Douglas I.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: /dk/atira/pure/core/subjects/geography; Geography; Arctic; Tellbreen; Spitsbergen
• Online Access: https://doi.org/10.1111/geoa.12059; https://researchportal.port.ac.uk/portal/en/publications/dendritic-subglacial-drainage-systems-in-cold-glaciers-formed-by-cutandclosure-processes(6bc17d24-9dad-466e-b677-4293fed3b401).html; https://researchportal.port.ac.uk/ws/files/1802021/Naegeli_et_al._2014_GEoA_accepted_manuscript_.pdf; http://onlinelibrary.wiley.com/doi/10.1111/geoa.12059/abstract;jsessionid=30C6CE4798655A8FE80D297BF4A7C9B3.f03t04

The routing and storage of meltwater and the configuration of drainage systems in glaciers exert a profound influence on glacier behaviour. However, little is known about the hydrological systems of cold glaciers, which form a significant proportion of the total glacier population in the climate sensitive region of the High Arctic. Using glacio-speleological techniques, we obtained direct access to explore and survey three conduit systems and one moulin within the tongue area of Tellbreen, a small cold-based valley glacier in central Spitsbergen. More than 600 m of conduits were surveyed and mapped in plan, profile and cross-section view to analyse the configuration of the drainage system. The investigations revealed that cold-based glaciers can exhibit a dendritic drainage network with supra-, en- and subglacial components formed most likely by cut-and-closure processes as well as surface-to-bed drainage via moulins. Furthermore, we observed that water is stored within the glacier and released gradually via subglacial conduits during the winter months, forming a large and active icing in the proglacial area. The presence of supra-, en- and subglacial components, the surface-to-bed moulin and the dendritic subglacial drainage network suggest that existing models and understanding of the hydrology of cold glaciers needs to be re-evaluated, mostly concerning the different possible pathways and processes that form the hydrological system.