Brief Communication: Further summer speedup of Jakobshavn Isbræ

• Published in: The Cryosphere
• Main Authors: Joughin, Ian, Smith, Ben, Shean, David, Floricioiu, Dana
• Other Authors: Bamber, Jonathan L., Gruber, Stephan, Gudmunsson, Hilmar G., van den Broeke, Michiel
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2014
• Subjects: SAR-Signalverarbeitung; Jakobshavn Isbræ; Jakobshavn; Jakobshavn isbræ; The Cryosphere
• Online Access: https://elib.dlr.de/92560/; http://www.the-cryosphere.net/8/209/2014/

We have extended the record of flow speed on Jakobshavn Isbræ through the summer of 2013. These new data reveal large seasonal speedups, 30 to 50% greater than previous summers. At a point a few kilometres inland from the terminus, the mean annual speed for 2012 is nearly three times as great as that in the mid-1990s, while the peak summer speeds are more than a factor of four greater. These speeds were achieved as the glacier terminus appears to have retreated to the bottom of an over-deepened basin with a depth of ~1300m below sea level. The terminus is likely to reach the deepest section of the trough within a few decades, after which it could rapidly retreat to the shallower regions ~50 km farther upstream, potentially by the end of this century.