Send to

Choose Destination
Sci Adv. 2019 Apr 24;5(4):eaau1380. doi: 10.1126/sciadv.aau1380. eCollection 2019 Apr.

Ice-stream demise dynamically conditioned by trough shape and bed strength.

Author information

Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, UK.
British Geological Survey, The Lyell Centre, Edinburgh EH14 4AP, UK.
Department of Geography and Planning, Durham University, Durham DH1 3LE, UK.
Scottish Universities Environmental Research Centre, East Kilbride, Glasgow G75 0QF, UK.
Department of Geography, University of Liverpool, Liverpool L69 3BX, UK.
Department of Geography, University of Sheffield, Sheffield S10 2TN, UK.
School of Ocean Sciences, Bangor University, Menai Bridge LL59 5AB, UK.
NERC Radiocarbon Facility, East Kilbride, Glasgow G75 0QF, UK.
Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth SY23 3DB, UK.


Ice sheet mass loss is currently dominated by fast-flowing glaciers (ice streams) terminating in the ocean as ice shelves and resting on beds below sea level. The factors controlling ice-stream flow and retreat over longer time scales (>100 years), especially the role of three-dimensional bed shape and bed strength, remain major uncertainties. We focus on a former ice stream where trough shape and bed substrate are known, or can be defined, to reconstruct ice-stream retreat history and grounding-line movements over 15 millennia since the Last Glacial Maximum. We identify a major behavioral step change around 18,500 to 16,000 years ago-out of tune with external forcing factors-associated with the collapse of floating ice sectors and rapid ice-front retreat. We attribute this step change to a marked geological transition from a soft/weak bed to a hard/strong bed coincident with a change in trough geometry. Both these factors conditioned and ultimately hastened ice-stream demise.

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center