8.2 ka event North Sea hydrography determined by bivalve shell stable isotope geochemistry

Estrella-Martínez, J., Ascough, P. L. , Schöne, B. R., Scourse, J. D. and Butler, P. G. (2019) 8.2 ka event North Sea hydrography determined by bivalve shell stable isotope geochemistry. Scientific Reports, 9, 6753. (doi: 10.1038/s41598-019-43219-1) (PMID:31043648) (PMCID:PMC6494846)

Abstract

The abrupt 8.2 ka cold event has been widely described from Greenland and North Atlantic records. However, its expression in shelf seas is poorly documented, and the temporal resolution of most marine records is inadequate to precisely determine the chronology of major events. A robust hydrographical reconstruction can provide an insight on climatic reaction times to perturbations to the Atlantic Meridional Overturning Circulation. Here we present an annually-resolved temperature and water column stratification reconstruction based on stable isotope geochemistry of Arctica islandica shells from the Fladen Ground (northern North Sea) temporally coherent with Greenland ice core records. Our age model is based on a growth increment chronology obtained from four radiometrically-dated shells covering the 8290–8100 cal BP interval. Our results indicate that a sudden sea level rise (SSLR) event-driven column stratification occurred between ages 8320–8220 cal BP. Thirty years later, cold conditions inhibited water column stratification but an eventual incursion of sub-Arctic waters into the North Sea re-established density-driven stratification. The water temperatures reached their minimum of ~3.7 °C 55 years after the SSLR. Intermittently-mixed conditions were later established when the sub-Arctic waters receded.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ascough, Dr Philippa
• Authors: Estrella-Martínez, J., Ascough, P. L., Schöne, B. R., Scourse, J. D., and Butler, P. G.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Scientific Reports
• Publisher: Nature Research
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2019 The Authors
• First Published: First published in Scientific Reports 9(1):6753
• Publisher Policy: Reproduced under a Creative Commons License