Inland advance of supraglacial lakes in north-west Greenland under recent climatic warming

• Main Authors: Gledhill, LA, Williamson, AG
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2018
• Subjects: arctic glaciology; climate change; ice and climate; melt - surface; remote sensing; Arctic; Greenland; Climate change; Ice Sheet
• Online Access: https://www.repository.cam.ac.uk/handle/1810/273354; https://doi.org/10.17863/CAM.20386

The inland advance of supraglacial lakes (SGLs) towards the interior regions of the Greenland Ice Sheet (GrIS) may have implications for the water volumes reaching the subglacial drainage system, and could consequently affect long-term ice-sheet dynamics. Here, we investigate changes to the areas, volumes, and elevation distributions of over 8000 manually delineated SGLs using 44 Landsat images of a 6200 km2 sector of north-west Greenland over three decades (1985–2016). Our results show that SGLs have advanced to higher maximum (+418 m) and mean (+299 m) elevations, and that there has been a near-doubling of total regional SGL areas and volumes over the study period, accelerating after 2000. These changes were primarily caused by an increased SGL area and volume at high (≥ 1200 m a.s.l.) elevations, where SGL coverage increased by over 2750 % during the study period. Many of the observed changes, particularly the post-2000 accelerations, were driven by changes to regional surface-temperature anomalies. This study demonstrates the past and accelerating response of the GrIS’s hydrological system due to climatic warming, indicating an urgent need to understand whether the increasingly inland SGLs will be capable of hydrofracture in the future, thus determining their potential implications for ice-sheet dynamics. LAG received a Hugh Brammer Vacation Study Grant (Downing College, Cambridge) to conduct the majority of the research. AGW was in receipt of a UK Natural Environment Research Council PhD studentship awarded through the Cambridge Earth System Science Doctoral Training Partnership (grant number: NE/L002507/1).