Supraglacial forcing of subglacial drainage in the ablation zone of the Greenland ice sheet

• Published in: Geophysical Research Letters
• Main Authors: Bartholomew, Ian, Nienow, Peter, Sole, Andrew, Mair, Douglas, Cowton, Thomas, Palmer, Steven, Wadham, Jemma
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: Greenland; glacier; Ice Sheet
• Online Access: https://research-portal.st-andrews.ac.uk/en/publications/ff8a3992-73b9-43a7-82cd-2fcff8432506; https://doi.org/10.1029/2011GL047063; http://www.scopus.com/inward/record.url?scp=79955411433&partnerID=8YFLogxK

We measure hydrological parameters in meltwater draining from an outlet glacier in west Greenland to investigate seasonal changes in the structure and behaviour of the hydrological system of a large catchment in the Greenland ice sheet (GrIS). Our data reveal seasonal upglacier expansion and increase in hydraulic efficiency of the subglacial drainage system, across a catchment >600 km 2 , to distances >50 km from the ice-sheet margin. This expansion occurs episodically in response to the drainage of surface meltwaters into a hitherto inefficient subglacial drainage system as new input locations become active progressively further upglacier; this system is similar to Alpine glaciers. These observations provide the first synopsis of seasonal hydrological behaviour in the ablation zone of the GrIS.