Extreme sensitivity in Snowball Earth formation to mountains on PaleoProterozoic supercontinents

Walsh, Amber, Ball, Thomas and Schultz, David M. (2019) Extreme sensitivity in Snowball Earth formation to mountains on PaleoProterozoic supercontinents. Scientific Reports, 9 (1). ISSN 2045-2322

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Abstract

During the PaleoProterozoic 2.45 to 2.2 billion years ago, several glaciations may have produced Snowball Earths. These glacial cycles occurred during large environmental change when atmospheric oxygen was increasing, a supercontinent was assembled from numerous landmasses, and collisions between these landmasses formed mountain ranges. Despite uncertainties in the composition of the atmosphere and reconstruction of the landmasses, paleoclimate model simulations can test the sensitivity of the climate to producing a Snowball Earth. Here we present a series of simulations that vary the atmospheric methane concentration and latitudes of west–east-oriented mountain ranges on an idealised supercontinent. For a given methane concentration, the latitudes of mountains control whether a Snowball Earth forms or not. Significantly, mountains in middle latitudes inhibited Snowball Earth formation, and mountains in low latitudes promoted Snowball Earth formation, with the supercontinent with mountains at ±30° being most conducive to forming a Snowball Earth because of reduced albedo at low latitudes. We propose that the extreme sensitivity of a Snowball Earth to reconstructions of the paleogeography and paleoatmospheric composition may explain the observed glaciations, demonstrating the importance of high-quality reconstructions to improved understanding of this early period in Earth’s history.

Item Type: Article
Uncontrolled Keywords: general ,/dk/atira/pure/subjectarea/asjc/1000
Faculty \ School: Faculty of Science > School of Environmental Sciences
Faculty of Science > Tyndall Centre for Climatic Change
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Depositing User: LivePure Connector
Date Deposited: 01 Mar 2019 14:30
Last Modified: 24 Oct 2020 00:09
URI: https://ueaeprints.uea.ac.uk/id/eprint/70068
DOI: 10.1038/s41598-019-38839-6

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