Karen Luise Knudsen (e-mail: firstname.lastname@example.org) and Peter Kristensen (e-mail: email@example.com), Department of Earth Sciences, Aarhus University, DK-8000 Aarhus C, Denmark; Hui Jiang (e-mail: firstname.lastname@example.org), Key Laboratory of Geographic Information Science, East China Normal University, Shanghai 200062, China; Philip L. Gibbard (e-mail: email@example.com), Cambridge Quaternary Department of Geography, University of Cambridge, Downing Street, Cambridge CB2 3EN, UK; Heikki Haila, Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, FIN-00014, Finland
Early Last Interglacial palaeoenvironments in the western Baltic Sea: benthic foraminiferal stable isotopes and diatom-based sea-surface salinity
Article first published online: 5 APR 2011
© 2011 The Authors. Boreas © 2011 The Boreas Collegium
Volume 40, Issue 4, pages 681–696, October 2011
How to Cite
KNUDSEN, K. L., JIANG, H., KRISTENSEN, P., GIBBARD, P. L. and HAILA, H. (2011), Early Last Interglacial palaeoenvironments in the western Baltic Sea: benthic foraminiferal stable isotopes and diatom-based sea-surface salinity. Boreas, 40: 681–696. doi: 10.1111/j.1502-3885.2011.00206.x
- Issue published online: 27 SEP 2011
- Article first published online: 5 APR 2011
- received 21st December 2010, accepted 21st February 2011.
Knudsen, K. L., Jiang, H., Kristensen, P., Gibbard, P. L. & Haila, H. 2011: Early Last Interglacial palaeoenvironments in the western Baltic Sea: benthic foraminiferal stable isotopes and diatom-based sea-surface salinity. Boreas, 10.1111/j.1502-3885.2011.00206.x. ISSN 0300-9483.
Stable isotopes from benthic foraminifera, combined with diatom assemblage analysis and diatom-based sea-surface salinity reconstructions, are used for the interpretation of changes in bottom- and surface-water conditions through the early Eemian at Ristinge Klint in the western Baltic Sea. Correlation of the sediments with the Eemian Stage is based on a previously published pollen analysis that indicates that they represent pollen zones E2–E5 and span ∼3400 years. An initial brackish-water phase, initiated c. 300 years after the beginning of the interglacial, is characterized by a rapid increase in sea-surface and sea-bottom salinity, followed by a major increase at c. 650 years, which is related to the opening of the Danish Straits to the western Baltic. The diatoms allow estimation of the maximum sea-surface salinity in the time interval of c. 650–1250 years. After that, slightly reduced salinity is estimated for the interval of c. 1250–2600 years (with minimum values at c. 1600–2200 years). This may be related to a period of high precipitation/humidity and thus increased freshwater run-off from land. Together with a continuous increase in the water depth, this may have contributed to the gradual development of a stratified water column after c. 1600 years. The stratification was, however, particularly pronounced between c. 2600 and 3400 years, a period with particularly high sea-surface temperature, as well as bottom-water salinity, and thus a maximum influence of Atlantic water masses. The freshwater run-off from land may have been reduced as a result of particularly high summer temperatures during the climatic optimum.