Quaternary of Norden

Abstract

The Nordic countries have experienced multiple glaciations and intervening interglacials during the last ca. 2.5-3 million years. Although evidence from Greenland and Iceland shows that ice sheets started to expand some time before 3 Ma, little is known about the glaciations and intervening interglacials older than the last Glacial Maximum due to repeated phases of glacial erosion and reworking. The extensive Saalian glaciation (c. 140 ka BP) contributed to high sea levels in Greenland and in the Baltic area during the early part of the last interglacial (Eemian). Temperatures were about 5 ºC higher during the Eemian than they are today and the Greenland ice sheet was reduced to about half of its present size, causing globally higher sea levels than we have today. Ice extent in Fennoscandia was restricted during early Weichselian stadials, but middle Weichselian ice advances in Scandinavia reached as far as Denmark. During the Last Glacial Maximum, large ice sheets were present in all Nordic countries and coalesced with neighboring ice sheets. Deglaciation commenced around 17-15 ka BP in most areas and was promoted by rapidly rising global sea level and glacial isostasy. The Younger Dryas cold event(c. 12.6-11.5 ka BP) is seen as a short-term re-advance, still-stand or fluctuation of land-based ice sheet margins. Around 7-9 ka BP ice sheets had disappeared or had attained their present size. While uplift is still going on in some regions, others are subject to submergence. The different stages of development of the Baltic Sea are an example of how the intricate interplay between glacial eustasy and isostasy influences sedimentation, basin size and drainage patterns.

Northern glacial refugia and altitudinal niche divergence shape genome‐wide differentiation in the emerging plant model Arabidopsis arenosa

“…; Wohlfarth et al . ). It is thus plausible that the admixture event took part in the areas where both putative parents still co‐occur and hybridize (i.e.…”

Extent, age and dynamics of Marine Isotope Stage 3 glaciations in the southwestern Baltic Basin

“…(2004), Mangerud (2004), Müller (2004), Zelès & Markots (2004), Kalm (2006), Helmens et al . (2007), Houmark‐Nielsen (2007), Stephan (2007), Wohlfarth et al . (2008), Larsen et al .…”

“…2001). Recent compilations of Scandinavian palaeoenvironmental records indicate that the repeated outflow of glaciers from the SIS over Danish, Norwegian, Swedish, Finnish and Baltic uplands during most of the Weichselian was interrupted by episodes of strongly reduced ice‐sheet distribution accompanied by the colonization of low Arctic flora and fauna in central Scandinavia (Wohlfarth et al . 2008).…”

“…Whereas the SIS experienced steady sheet flow over southwest Scandinavia during the main ice advance at the peak of the Last Glacial Maximum (LGM, 25–20 kyr BP), fast‐moving land‐based ice streams were fed through shallow basins bordering the SIS earlier and immediately thereafter (Houmark‐Nielsen 2004; Wohlfarth et al . 2008).…”

Comparative phylogeography of the ants Myrmica ruginodis and Myrmica rubra

“…For the groups that fitted the model, we estimated tau (τ) with 95% confidence intervals (Rogers & Harpending, 1992). For estimating the mutation rate u, we chose the haplogroups that had tip haplotypes from the areas previously covered by glacial ice, 2-1W (west) and 2-2, and used their τ values to estimate t. If the expansion of the haplogroups 2-1W and 2-2 occurred after the LGM and t was roughly 8-15 ka (Hubberten et al, 2004;Wohlfarth et al, 2008), we estimated that the mutation rate u would be 2-5% Myr À1 . We calculated u from the equation u = m t l, where m t is the length of the sequence (1438 bp) and l is the mutation rate per nucleotide per year (Rogers & Harpending, 1992).…”