Elsevier

Quaternary Science Reviews

Volume 124, 15 September 2015, Pages 209-223
Quaternary Science Reviews

The 5.2 ka climate event: Evidence from stable isotope and multi-proxy palaeoecological peatland records in Ireland

https://doi.org/10.1016/j.quascirev.2015.07.026Get rights and content
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Highlights

  • The 5.2 ka event has been identified globally as a period of abrupt climate change.

  • Multiple stable isotope records from Ireland show clear evidence for 5.2 ka event.

  • Sluggan Moss possesses a strong palaeoecological evidence of 5.2 ka event.

  • 5.2 ka event caused by prolonged positive North Atlantic Oscillation conditions.

  • The value of research into peat-based stable isotopes is highlighted.

Abstract

Evidence for a major climate event at 5.2 ka has been reported globally and is associated with considerable societal disruption, but is poorly characterised in northwest Europe. This event forms part of a broader period of re-organisation in the Earth's ocean-atmosphere circulation system between 6 and 5 ka. This study tests the nature and timing of the event in northwest Europe, a region highly sensitive to change in meridional overturning circulation and mid-latitude westerly airflow. Here we report three high-resolution Irish multi-proxy records obtained from ombrotrophic peatlands that have robust chronological frameworks. We identify the 5.2 ka event by a sustained decrease in δ18Ocellulose at all three sites, with additional and parallel changes in δ13Ccellulose and palaeoecological (testate amoebae, plant macrofossil and humification) data from two sites in northern Ireland. Data from Sluggan Moss demonstrate a particularly coherent shift towards wetter conditions. These data support the hypothesis that the event was caused by a prolonged period of positive North Atlantic Oscillation conditions, resulting in pervasive cyclonic weather patterns across northwest Europe, increasing precipitation over Ireland.

Keywords

Peatlands
Multi-proxy
Stable isotopes
Testate amoebae
Plant macrofossils
Ireland
5.2 ka event
Mid-Holocene
North Atlantic Oscillation (NAO)

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