Response of the large-scale subglacial drainage system of Northeast Greenland to surface elevation changes

• Published in: The Cryosphere
• Main Authors: N. B. Karlsson, D. Dahl-Jensen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2015
• Subjects: geo; envir; Greenland; glacier; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-9-1465-2015; http://www.the-cryosphere.net/9/1465/2015/tc-9-1465-2015.pdf; https://doaj.org/article/90070b41965242209d29539f7f42499c

The influence of subglacial water on the dynamics of ice flow has been the object of increasing interest in the past decade. In this study we focus on large-scale, long-term changes in surface elevation over Northeast Greenland and the corresponding changes in subglacial water routeways. Our results show that over timescales ranging from decades to millennia the area may experience redistribution of and fluctuation in subglacial water outflux under the main glacier outlets. The fluctuations in subglacial water routing occur even in the absence of external forcing. Based on these results we conclude that changes in the subglacial water routeways are an intrinsic part of the drainage basin dynamics, where the subglacial system is likely always in a transient state. The results also imply that fluctuations at the margins observed at present might originate from changes several hundred kilometres upstream. Since surface elevation changes may propagate upstream over timescales much longer than the observational period, the cause of the fluctuations may not be present in current observational records.