Paleomagnetic correlations between Scandinavian Ice-Sheet fluctuations and Greenland Dansgaard–Oeschger events, 45,000–25,000 yr B.P.

Abstract

Two paleomagnetic excursions, the Skjong correlated with the Laschamp (about 41,000 GISP2 yr B.P.) and the Valderhaug correlated with the Mono Lake (about 34,000 GISP2 yr B.P.), have been identified in stratigraphic superposition in laminated clay deposited in ice-dammed lakes in three large caves in western Norway. During both periods the margin of the Scandinavian Ice Sheet advanced and reached the continental shelf beyond the outermost coastline. The mild, 4000-yr-long Ålesund interstade, when the coast and probably much of the hinterland were ice-free, separated the two glacial advances. The two paleomagnetic excursions have also been indirectly identified as increased fluxes of 36 Cl and 10 Be in the GRIP ice core, Greenland. This article presents a correlation between ice-margin fluctuations of the Scandinavian Ice Sheet and the stratigraphy of GRIP/GISP cores, using the paleomagnetic excursions and the 36 Cl and 10 Be peaks and thus circumventing the application of different dates or time scales. Some of the fluctuations of the Scandinavian Ice Sheet were of the "Allerød/Younger Dryas type" in the sense that its margin retreated during mild interstades on Greenland and readvanced during cold stades. However, some fluctuations were apparently not in phase with the Greenland climate.

Late Weichselian fluvial evolution on the southern Kara Sea Shelf, North Siberia

“…River systems may either be deflected by ice sheets or be totally dammed. This has also been proposed by several workers for the middle Weichselian glaciation in Siberia, when the Ob and Yenisei rivers were thus re-routed southward into the Caspian Sea via the Aral Sea, instead of a northward drainage into the Kara Sea (Mangerud et al, 2003(Mangerud et al, , 2004). …”

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 .…”

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

“…A striking feature of the sediments in the cave is that the palaeomagnetic excursions Laschamp and Mono Lake have been identified in the clay beds below and above the Ålesund Interstadial bed, respectively (Larsen et al 1987; Løvlie & Sandnes 1987) and thus constrain the age of the Ålesund Interstadial to the period between these two excursions. These could be correlated with the Greenland ice core stratigraphy (Mangerud et al 2003) because during excursions the magnetic field was weakened, resulting in increased production of cosmogenic isotopes in the atmosphere and thus peaks in the deposition of 10 Be and 36 Cl on Greenland (Yiou et al 1997; Wagner et al 2000; Beer et al 2002). The midpoint of Laschamp is in Greenland Interstadial (GIS) 10, dated to 40.5–42 kyr BP in the GICC05 time scale (Svensson et al 2008).…”