Seasonal speedup along the western flank of the Greenland ice sheet

• Published in: Science
• Main Authors: Joughin, I, Das, SB, King, MA, Smith, BE, Howat, IM, Moon, T
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Assoc Advancement Science 2008
• Subjects: Earth Sciences; Physical Geography and Environmental Geoscience; Physical Geography and Environmental Geoscience not elsewhere classified; Greenland; glacier; Ice Sheet; Jakobshavn
• Online Access: https://doi.org/10.1126/science.1153288; http://ecite.utas.edu.au/81952

It has been widely hypothesized that a warmer climate in Greenland would increase the volume of lubricating surface meltwater reaching the ice-bedrock interface, accelerating ice flow and increasing mass loss. We have assembled a data set that provides a synoptic-scale view, spanning ice-sheet to outlet-glacier flow, with which to evaluate this hypothesis. On the ice sheet, these data reveal summer speedups (50 to 100%) consistent with, but somewhat larger than, earlier observations. The relative speedup of outlet glaciers, however, is far smaller (<15%). Furthermore, the dominant seasonal influence on Jakobshavn Isbrae's flow is the calving front's annual advance and retreat. With other effects producing outlet-glacier speedups an order of magnitude larger, seasonal melt's influence on ice flow is likely confined to those regions dominated by ice-sheet flow.