Search

Because global sea level during the last interglacial (LIG; 130–115 ka) was higher than today, the LIG is a useful approximate analogue for improving predictions of future sea-level rise. Here, we synthesize sea-level proxies for the LIG in the glaciated Northern Hemisphere for inclusion in the World Atlas of Last Interglacial Shorelines (WALIS) database. We describe 82 sites from Russia, northern Europe, Greenland and North America from a variety of settings, including boreholes, riverbank exposures and along coastal cliffs. Marine sediments at these sites were constrained to the LIG using a variety of radiometric methods (radiocarbon, uranium–thorium, potassium–argon), non-radiometric methods (amino acid dating, luminescence methods, electron spin resonance, tephrochronology) as well as various stratigraphic and palaeo-environmental approaches. In general, the sites reported in this paper do not offer constraint on the global LIG highstand, but rather evidence of glacial isostatic adjustment (GIA)-influenced sea-level positions following the Marine Isotope Stage 6 glaciation (MIS 6; 191–130 ka). Most of the proxies suggest that sea level was much higher during the LIG than at the present time. Moreover, many of the sites show evidence of regression due to sea-level fall (owing to glacial isostatic uplift), and some also show fluctuations that may reflect regrowth of continental ice or increased influence of the global sea-level signal. In addition to documenting LIG sea-level sites in a large swath of the Northern Hemisphere, this compilation is highly relevant for reconstructing the size of MIS 6 ice sheets through GIA modelling. The database is available at https://doi.org/10.5281/zenodo.5602212 (Dalton et al., 2021).

Because global sea level during the last interglacial (LIG; 130–115 ka) was higher than today, the LIG is a useful analogue for improving predictions of future sea level rise. Here, we synthesize sea level proxies for the LIG in the glaciated Northern Hemisphere for inclusion in the World Atlas of Last Interglacial Shorelines (WALIS) database. We describe 82 sites from Russia, northern Europe, Greenland and North America from a variety of settings, including boreholes, riverbank exposures and along coastal cliffs. Marine sediments at these sites were constrained to the LIG using a variety of radiometric methods (radiocarbon, U-Series dating, K-Ar dating), non-radiometric methods (amino acid dating, luminescence methods, and electron spin resonance, tephrochronology) as well as various stratigraphic and palaeoenvironmental approaches. As the areas in this database were covered by ice sheets from the penultimate glaciation and were affected by glacial isostatic adjustment (GIA), most of the proxies show that sea level was much higher than present during the LIG. Many of the sites show evidence of regression due sea level fall due to GIA uplift, and some also show fluctuations that may reflect regrowth of continental ice or increased influence of the global sea level signal. The database is available at https://doi.org/10.5281/zenodo.5602212 (Dalton et al., 2021).

Key geological sections on the southern part of the Kola Peninsula were investigated to reveal the evolution of the Late Pleistocene palaeoenvironments and the history of the last deglaciation of the area. Methods used were conventional sedimentological techniques, including palaeocurrent analysis and geomorphological observations. Optically stimulated luminescence dating was used to determine the age of sand-rich sediment units exposed in sections. The results indicate that the Eemian (MIS 5e) marine environment in the onshore coastal areas gradually changed into a glaciolacustrine environment. The first ice advance into the western part of the study area took place already during the Early Weichselian (MIS 5b?). After deglaciation, glaciolacustrine conditions were re-established in the area. Only one younger until is observed in the area; it cannot be excluded that this stems from a Middle Weichselian (MIS 4) glaciation over the area, though it is more probable that it is from the last Scandinavian ice sheet advance over the area during the Last Glacial Maximum (LGM). The southern and central coastal areas of the Kola Peninsula deglaciated between 16,000 and 12,000 years ago. The most prominent end moraine ridges, the Keiva II and Keiva I end moraines were formed in an interlobate zone between ice mass in the interior of the Kola Peninsula and the White Sea ice lobe during the Younger Dryas.

Southwestern Barents Sea sediments contain important information on Lateglacial and Holocene environmental development of the area, i.e. sediment provenance characteristics related to ice-flow patterns and ice drifting from different regional sectors. In this study, we present investigations of clay, heavy minerals, and ice-rafted debris from three sediment cores obtained from the SW Barents Sea. The sediments studied are subglacial/glaciomarine to marine in origin. The core sequences were divided into three lithostratigraphical units. The lowest, Unit 3, consists of laminated glaciomarine sediments related to regional deglaciation. The overlying Unit 2 is a diamicton, dominated by mud and oversized clasts. Unit 2 reflects a more ice-proximal glaciomarine sedimentary environment or even a subglacial depositional environment; its deposition may indicate a glacial re-advance or stillstand during an overall retreat. The uppermost Unit 1 consists of Holocene marine sediments and current-reworked sedimentary material with a relatively high carbonate content. A significant proportion of the sedimentary material could be derived from Svalbard and transported by sea ice or icebergs to the Barents Sea during the late deglacial phase. The Fennoscandian sources and local Mesozoic strata from the bottom of the Barents Sea are the likely provenances of sediments deposited during the deglacial and ice re-advance phases. Bottom currents and sea-ice transport were the main mechanisms influencing sedimentation during the Holocene. Our results indicate that the provenance areas can be reliably related to certain ice-flow sectors and transport mechanisms in the deglaciated Barents Sea.

We determined in situ cosmogenic 10Be ages for nine boulders sampled on the Salpausselka I (Ss I) Moraine. Previous dating of this moraine indicated that it formed during the Younger Dryas Stadial along the southern margin of the Scandinavian Ice Sheet in southern Finland. Our new exposure ages range from 10.9±1.0 to 13.5±1.2 10Be ka, with an error-weighted mean age of 12.4±0.7 10Be ka. Our results confirm four previous 10Be ages obtained 40 km northeast of our sample location. The combined data ( n = 13 ) indicate that retreat from the Ss I Moraine occurred at 12.5±0.7 10Be ka, in excellent agreement with an age of 12.1 ka for retreat from the Ss I Moraine based on varve chronologies. These results identify the Ss I Moraine as among the best-dated margins associated with Late Quaternary ice sheets.