Seasonal Speedup Along the Western Flank of the Greenland Ice Sheet

作者：Ian Joughin, Sarah B. Das, Matt A. King, Ben Smith, Ian M. Howat, Twila Moon · 发表于：Science · 年份：2008 · DOI：10.1126/science.1153288 · 被引用次数：487 · 研究领域：Cryospheric studies and observations、Winter Sports Injuries and Performance、Climate change and permafrost

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.