¹⁴C‐dated fluctuations of the western flank of the Scandinavian Ice Sheet 45–25 kyr BP compared with Bølling–Younger Dryas fluctuations and Dansgaard–Oeschger events in Greenland

Abstract

We present 32 accelerator mass spectrometry (AMS) 14 C dates obtained on well-preserved bones from caves in western Norway. The resulting ages of 34-28 14 C kyr BP demonstrate that the coast was ice-free during the socalled Å lesund Interstadial. New AMS 14 C dates on shells aged 41-38 14 C kyr BP are evidence of an earlier (Austnes) ice-free period. The Å lesund Interstadial correlates with Greenland interstadials 8-7 and the Austnes Interstadial with Greenland interstadials 12-11. Between and after the two interstadials, the ice margin reached onto the continental shelf west of Norway. These events can be closely correlated with the Greenland ice core stratigraphy, partly based on identification of the Laschamp and Mono Lake palaeomagnetic excursions. We found that the pattern of the NGRIP d 18 O curves for the two periods Greenland Interstadial (GI) 8 to Greenland Stadial (GS) 8 and GI 1-GS 1 (Bølling-Younger Dryas) were strikingly similar, which leads us to suggest that the underlying causes of these climate shifts could have been the same. We therefore discuss some aspects of glacial fluctuations during the Bølling-Younger Dryas in order to elucidate processes during Dansgaard-Oeschger events.

Pink marine sediments reveal rapid ice melt and Arctic meltwater discharge during Dansgaard–Oeschger warmings

“…New data from Norway [43][44][45] , Sweden and Finland 46,47 indicate that the Scandinavian ice sheet during MIS 3 was more dynamic than previously recognized. The evidence is lacking in temporal ARTICLE resolution, but two rapid advances beyond the coastline of Norway seem well-documented 39,40,43 .…”

“…The second advance is correlated with Greenland stadial 7 and dated to c. 34.5 kyr BP. The intervening period includes the Ålesund interstadial, which has been correlated with the period corresponding to Greenland interstadials GI8-GI7 (38.2-34.5 kyr BP on the GICC05 timescale) 39,45 .…”

Timing of glacier response to Younger Dryas climatic cooling in Scotland

“…Here we report new evidence that provides more precise chronological constraints for growth of YD ice in the Loch Lomond Global and Planetary Change 79 (2011) (Palmer et al, 2010) and with some evidence for growth of the Main Inland Ice Sheet in Norway during the YD (Mangerud et al, 2010).…”

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

“…Whereas IRD fluxes indicate that the BIIS remained at the shelf edge (Wilson et al, 2002), cave sediments in western Norway indicate ice retreat to the present coast at 29.7 ka (Mangerud et al, 2010;Valen et al, 1996) and inter-till sediments in Denmark indicate ice recession from maximum limits there at 27 and 24 ka (HoumarkNielsen and Kjaer, 2003). Combined with the IRD flux increases initiated at 27 ka on the western Irish margin and at 25 ka on the Goban Spur (Scourse et al, 2009), this timing suggests the BIIS and FIS were not fixed at LGM limits but fluctuated markedly, consistent with the behaviour of the last BIIS in simulations (Hubbard et al, 2009).…”