Modelling Late Weichselian evolution of the Eurasian ice sheets forced by surface meltwater-enhanced basal sliding

• Published in: Journal of Glaciology
• Main Authors: Clason, Caroline C., Applegate, Patrick, Holmlund, Per
• Format: Article in Journal/Newspaper
• Language: English
• Published: Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK) 2014
• Subjects: glacial geomorphology; glacier hydrology; ice-sheet modelling; surface melt; Geosciences; Multidisciplinary; Multidisciplinär geovetenskap; Greenland; glacier; Ice Sheet; Journal of Glaciology
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-97432; https://doi.org/10.3189/2014JoG13J037

We simulated the Late Weichselian extent and dynamics of the Eurasian ice sheets using theshallow-ice approximation ice-sheet model SICOPOLIS. Our simulated Last Glacial Maximum ice-sheetextents closely resemble geomorphological reconstructions, and areas of modelled fast flow areconsistent with the known locations of palaeo-ice streams. Motivated by documented velocity responseto increased meltwater inputs on Greenland, we tested the sensitivity of the simulated ice sheet to thesurface meltwater effect (SME) through a simple parameterization relating basal sliding to local surfacemelt rate and ice thickness. Model runs including the SME produce significantly reduced ice volumeduring deglaciation, with maximum ice surface velocities much greater than in similar runs that neglectthe SME. We find that the simple treatment of the SME is not applicable across the whole ice sheet;however, our results highlight the importance of the SME for dynamic response to increased melting.The southwest sector of the Scandinavian ice sheet is most sensitive to the SME, with fast flow in theBaltic ice stream region shutting off by 15 kaBP when the SME is turned on, coincident with a retreat ofthe ice-margin position into the Gulf of Bothnia.