Millennial-scale fluctuations of the European Ice Sheet at the end of the last glacial, and their potential impact on global climate

Abstract

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Glacial chronology of the Sierra Nevada, California, from the Last Glacial Maximum to the Holocene

“…The west side had Fig. 3(a) (Zaragosi et al, 2001;Toucanne et al, 2015). Toucanne et al (2015), based on synthesis of previous studies.…”

“…The background patterns are derived from a chronology of the retreat of the European Ice Sheet (EIS) based on interpretation of neodymium isotopes and a wide range of other provenance and paleoclimate indicators in cores from the Bay of Biscay, by Toucanne et al (2015). The vertical pink bars labeled "R" are 'runoff events' in the 'Channel river' that flowed in the present position of the English Channel and drained nearly all of the southern margin of the European Ice Sheet.…”

“…The vertical pink bars labeled "R" are 'runoff events' in the 'Channel river' that flowed in the present position of the English Channel and drained nearly all of the southern margin of the European Ice Sheet. Toucanne et al (2015) interpreted these events as the result of melting and retreat of the southern margin of the ice sheet. The darker pink bar labeled "pediastrum event" shows the timing of the deposition of large numbers of pediastrum, a freshwater algae that presumably grew in proglacial and supraglacial lakes and indicates especially rapid and voluminous melting of the ice sheet (Zaragosi et al, 2001).…”

The last glaciation in Caithness, Scotland: revised till stratigraphy and ice-flow paths indicate multiple ice flow phases

“…Peak IRD flux coincident with Heinrich Event 2 at 24 ka is a feature of all records of the BIIS on its western margin (Scourse et al, 2009). The FIS margin was also close to its southernmost limits in Europe from 24.3 to 23.4 ka, 22.5 to 21.3 ka and again from 20.3-18.7 ka (Toucanne et al, 2015). This LGM timing is difficult to reconcile with radiocarbon dates on marine shells from the Witch Ground Basin that indicate the establishment of ice free conditions after 25 k cal.…”

The role of Arctic Ocean freshwater during the past 200 ky

“…Since the decay of the ice sheets surrounding the Nordic Seas was largely contemporaneous with events in the Arctic (cf. [9,18,74,85,88]), it appears difficult to distinguish between the individual effects of freshwater fluxes from the Greenland, Barents Sea and Scandinavian ice sheets and those originating from the Arctic Ocean. Therefore, the impact of deglacial excess Arctic freshwater discharge on the oceanographic system in the northern North Atlantic and the meridional overturning circulation remains elusive, at least for the time before the onset of the Younger Dryas (YD) cold event.…”