Ice-stream stability on a reverse bed slope

• Main Authors: Stewart S. R. Jamieson, Andreas Vieli, Stephen J. Livingstone, Colm Ó Cofaigh, Chris Stokes, Claus-dieter Hillenbr, Julian A. Dowdeswell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2012
• Subjects: Antarctic; Greenland; Marguerite; Marguerite Bay; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.400.7568; http://www.seas.harvard.edu/climate/seminars/pdfs/Jamieson_NatGeo_2012.pdf

Marine-based ice streams whose beds deepen inland are thought to be inherently unstable1–3. This instability is of particular concern because significant portions of the marinebased West Antarctic and Greenland ice sheets are losing mass and their retreat could contribute significantly to future sea-level rise4–7. However, the present understanding of icestream stability is limited by observational records that are too short to resolve multi-decadal to millennial-scale behaviour or to validate numerical models8. Here we present a dynamic numerical simulation of Antarctic ice-stream retreat since the Last Glacial Maximum (LGM), constrained by geophysical data, whose behaviour is consistent with the geomorphological record. We find that retreat of Marguerite Bay Ice Stream following the LGM was highly nonlinear and was interrupted by stabilizations on a reverse-sloping bed, where theory predicts