Rapid last-deglacial thinning and retreat of the marine-terminating southwestern Greenland ice sheet

The Greenland Ice Sheet during the last glacial cycle: Current ice loss and contribution to sea-level rise from a palaeoclimatic perspective

“…Thus the LGM ice margin probably extended all the way to the shelf edge in the Disko-and Uummannaq Troughs Jennings et al, 2013), and this supports the idea that the Hellefisk moraines reflect the LGM ice extent in the area immediately to the south. It is noted by Funder et al (2011) that their LGM reconstruction should be regarded as a minimum scenario, particularly in northeast Greenland, and a range of new results indicate that it is too conservative also in west Greenland (Corbett et al, 2013;Ó Cofaigh et al, 2013;Roberts et al, 2013;Lane et al, 2014;Winsor et al, 2015). Some of these more recent studies were considered by Lecavalier et al (2014) when they constructed the LGM mask for their model simulation (Fig.…”

“…Kelly, 1985;Roberts et al, 2009), however, from recent studies (e.g. Corbett et al, 2013;Roberts et al, 2013;Lane et al, 2014;Winsor, 2014;Winsor et al, 2015) it seems likely that most trimlines in Greenland reflect an englacial thermal boundary rather than the LGM ice surface, i.e. that they mark a transition from warm-based ice (below the trimline) to cold-based, non-erosive ice (above the trimline).…”

“…4A), but they stress that this is most probably a minimum scenario, given that some of the deposits may be recessional features formed during retreat of the ice margin rather than when it was at its largest. Other authors have favoured a scenario with more extensive LGM ice cover in this area (Ó Cofaigh et al, 2004;Håkansson et al, 2007Håkansson et al, , 2009, arguing that areas previously interpreted as being ice-free based on weathering limits could rather have been covered by cold based, non-erosive ice during the LGM, an interpretation that seems likely in light of new results from west Greenland (Corbett et al, 2013;Roberts et al, 2013;Lane et al, 2014;Winsor, 2014;Winsor et al, 2015).…”

“…4A). Originally Kelly (1985) interpreted the inner Fiskebanke moraines to have formed during the LGM based on altitudes of onshore weathering limits (Rinterknecht et al, 2009;Roberts et al, 2009); however, as discussed above these trimlines likely reflect englacial thermal boundaries rather than the top of the ice sheet (van Tatenhove et al, 1996;Weidick et al, 2004;Winsor et al, 2015). Thus the LGM ice margin probably extended all the way to the shelf edge in the Disko-and Uummannaq Troughs Jennings et al, 2013), and this supports the idea that the Hellefisk moraines reflect the LGM ice extent in the area immediately to the south.…”

“…It was the period when the ice margin first retreated onto land after the LGM along most of the Greenland coast, and in many areas it retreated all the way to its present position and beyond (Hughes et al, 2012;Larsen et al, 2014;Carlson et al, 2014;Dyke et al, 2014;Winsor, 2014;Winsor et al, 2015).…”