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

QUATERNARY SCIENCE REVIEWS

卷:124

Article

Roland, T. P.¹  Daley, T. J.²  Caseldine, C. J.¹  Charman, D. J.¹  Turney, C. S. M.³  Amesbury, M. J.¹  Thompson, G. J.¹  Woodley, E. J.¹ 

[1] Univ Exeter, Coll Life & Environm Sci, Geog, Exeter EX4 4QJ, Devon, England

[2] Univ Plymouth, Sch Geog Earth & Environm Sci, Plymouth PL4 8AA, Devon, England

[3] Univ New S Wales, Sch Biol Earth & Environm Sci, Sydney, NSW 2052, Australia

关键词: Peatlands;    Multi-proxy;    Stable isotopes;    Testate amoebae;    Plant macrofossils;    Ireland;    52 ka event;    Mid-Holocene;    North Atlantic Oscillation (NAO);   

DOI  :  10.1016/j.quascirev.2015.07.026

来源: Elsevier

【 摘 要 】

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 delta O-18(cellulose) at all three sites, with additional and parallel changes in delta C-13(cellulose) 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. (C) 2015 The Authors. Published by Elsevier Ltd.

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