Quantifying supraglacial meltwater pathways in the Paakitsoq region, West Greenland

• Main Authors: Koziol, C, Arnold, N, Pope, A, Colgan, W
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2017
• Subjects: crevasses; glacier hydrology; surface-melt; Greenland; glacier; Ice Sheet
• Online Access: https://www.repository.cam.ac.uk/handle/1810/263259; https://doi.org/10.17863/CAM.8585

Increased summer ice velocities on the Greenland ice sheet are driven by meltwater input to the subglacial environment. However, spatial patterns of surface input and partitioning of meltwater between different pathways to the base remain poorly understood. To further our understanding of surface drainage, we apply a supraglacial hydrology model to the Paakitsoq region, West Greenland for three contrasting melt seasons. During an average melt season, crevasses drain ~47% of surface runoff, lake hydrofracture drains ~3% during the hydrofracturing events themselves, while the subsequent surface-to-bed connections drain ~21% and moulins outside of lake basins drain ~15%. Lake hydrofracture forms the primary drainage pathway at higher elevations (above ~850 m) while crevasses drain a significant proportion of meltwater at lower elevations. During the two higher intensity melt seasons, model results show an increase (~5 and ~6% of total surface runoff) in the proportion of runoff drained above ~1300 m relative to the melt season of average intensity. The potential for interannual changes in meltwater partitioning could have implications for how the dynamics of the ice sheet respond to ongoing changes in meltwater production. C.P. Koziol acknowledges the support of St. John's College (Cambridge). A. Pope was supported by NSF award GEO-1331100 and W. Colgan was supported by NASA award NNX13AP73G. WorldView imagery was provided by the Polar Geospatial Center at the University of Minnesota, which is supported by grant ANT-1043681 from the US National Science Foundation.