Sub-arctic Holocene climatic and oceanographic variability in Stjernsund, northern Norway: evidence from benthic foraminifera and stable isotopes

A high-resolution record, covering 9.3–0.2 ka BP, from the sub-arctic Stjernsund (70°N) was studied for benthic foraminiferal faunas and stable isotopes, revealing three informally named main phases during the Holocene. The Early- to Mid-Holocene (9.3–5.0 ka BP) was characterized by the strong influ...

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Bibliographic Details
Published in:Boreas
Main Authors: Joseph, Nina, López Correa, Matthia, Schönfeld, Joachim, Rüggeberg, Andres, Freiwald, André
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2013
Subjects:
Arctic
Barents Sea
Norway
Climate change
Foraminifera*
Nordic Seas
north atlantic current
North Atlantic
Northern Norway
Online Access:https://oceanrep.geomar.de/id/eprint/19264/
https://oceanrep.geomar.de/id/eprint/19264/1/bor303.pdf
https://doi.org/10.1111/j.1502-3885.2012.00303.x
Description
Summary:A high-resolution record, covering 9.3–0.2 ka BP, from the sub-arctic Stjernsund (70°N) was studied for benthic foraminiferal faunas and stable isotopes, revealing three informally named main phases during the Holocene. The Early- to Mid-Holocene (9.3–5.0 ka BP) was characterized by the strong influence of the North Atlantic Current (NAC), which prevented the reflection of the Holocene Climatic Optimum (HCO) in the bottom-water temperature. During the Mid-Holocene Transition (5.0–2.5 ka BP), a turnover of benthic foraminiferal faunas occurred, Atlantic Water species decreased while Arctic-Polar species increased, and the oxygen isotope record showed larger fluctuations. Those variations correspond to a period of global climate change, to spatially more heterogeneous benthic foraminiferal faunas in the Nordic Seas region, and to regionally diverging terrestrial temperatures. The Cool Late Holocene (2.5–0.2 ka BP) was characterized by increased abundances of Arctic-Polar species and a steady cooling trend reflected in the oxygen isotopes. In this period, our record differs considerably from those on the SW Barents Sea shelf and locations farther south. Therefore, we argue that regional atmospheric cooling triggered the late Holocene cooling trend. Several cold episodes centred at ∼8.3, ∼7.8, ∼6.5, ∼4.9, ∼3.9 and ∼3.3 ka BP were identified from the benthic foraminiferal faunas and the δ18O record, which correlated with marine and atmospherically driven proxy records. This suggests that short-term cold events may result from reduced heat advection via the NAC or from colder air temperatures.

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