Projections for future radiocarbon content in dissolved inorganic carbon in hardwater lakes: a retrospective approach

Blattmann, T. M., Wessels, M., McIntyre, C. P. and Eglinton, T. I. (2018) Projections for future radiocarbon content in dissolved inorganic carbon in hardwater lakes: a retrospective approach. Radiocarbon, 60(3), pp. 791-800. (doi:10.1017/RDC.2018.12)

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Abstract

Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI14C data from 2013 and 1969 for Lake Constance reveals that this is not a valid assumption. We hypothesize that changes in atmospheric carbon contributions to lake water DIC have taken place due to anthropogenically forced eutrophication in the 20th century. A return to more oligotrophic conditions in the lake led to reoxygenation and enhanced terrigenous organic matter remineralization, contributing to lake water DIC. Such comparisons using DI14C measurements from different points in time enable nonlinear changes in lake water DIC source and signature to be disentangled from concurrent anthropogenically induced changes in atmospheric 14C. In the future, coeval changes in lake dynamics due to climate change are expected to further perturb these balances. Depending on the scenario, Lake Constance DI14C is projected to decrease from the 2013 measured value of 0.856 Fm to 0.54–0.62 Fm by the end of the century.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Mcintyre, Dr Cameron
Authors: Blattmann, T. M., Wessels, M., McIntyre, C. P., and Eglinton, T. I.
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Radiocarbon
Publisher:Cambridge University Press
ISSN:0033-8222
ISSN (Online):1945-5755
Published Online:04 March 2018
Copyright Holders:Copyright © 2018 Arizona Board of Regents on behalf of the University of Arizona
First Published:First published in Radiocarbon 60(3):791-800
Publisher Policy:Reproduced under a Creative Commons License

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