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

• Published in: Boreas
• Main Authors: Joseph, Nina, López Correa, Matthias, Schönfeld, Joachim, Rüggeberg, Andres, Freiwald, André
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2012
• Subjects: Arctic; Norway; Climate change; Foraminifera*; Northern Norway
• Online Access: http://dx.doi.org/10.1111/j.1502-3885.2012.00303.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.2012.00303.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.2012.00303.x

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 H olocene. The E arly‐ to M id‐ H olocene (9.3–5.0 ka BP ) was characterized by the strong influence of the N orth A tlantic C urrent ( NAC ), which prevented the reflection of the H olocene C limatic O ptimum ( HCO ) in the bottom‐water temperature. During the M id‐ H olocene Transition (5.0–2.5 ka BP ), a turnover of benthic foraminiferal faunas occurred, A tlantic W ater species decreased while A rctic‐ P olar 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 N ordic S eas region, and to regionally diverging terrestrial temperatures. The C ool L ate H olocene (2.5–0.2 ka BP ) was characterized by increased abundances of A rctic‐ P olar species and a steady cooling trend reflected in the oxygen isotopes. In this period, our record differs considerably from those on the SW B arents S ea 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 δ 18 O 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.