Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating.
Calculating cosmogenic-nuclide surface-exposure ages is critically dependent on a knowledge of the altitude of the sample site. Changes in altitude have occurred through time as a result of glacial isostatic adjustment (GIA), potentially altering local nuclide production rates and, therefore, surfac...
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Online Access: | http://dro.dur.ac.uk/27776/ http://dro.dur.ac.uk/27776/1/27776.pdf https://doi.org/10.1016/j.quascirev.2019.03.012 |
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ftunivdurham:oai:dro.dur.ac.uk.OAI2:27776 2023-05-15T13:48:01+02:00 Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. Jones, R.S. Whitehouse, P.L. Bentley, M.J. Small, D. Dalton, A.S. 2019-05-15 application/pdf http://dro.dur.ac.uk/27776/ http://dro.dur.ac.uk/27776/1/27776.pdf https://doi.org/10.1016/j.quascirev.2019.03.012 unknown Elsevier dro:27776 issn:0277-3791 doi:10.1016/j.quascirev.2019.03.012 http://dro.dur.ac.uk/27776/ https://doi.org/10.1016/j.quascirev.2019.03.012 http://dro.dur.ac.uk/27776/1/27776.pdf © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license(http://creativecommons.org/licenses/by/4.0/ CC-BY Quaternary science reviews, 2019, Vol.212, pp.206-212 [Peer Reviewed Journal] Article PeerReviewed 2019 ftunivdurham https://doi.org/10.1016/j.quascirev.2019.03.012 2020-06-04T22:25:27Z Calculating cosmogenic-nuclide surface-exposure ages is critically dependent on a knowledge of the altitude of the sample site. Changes in altitude have occurred through time as a result of glacial isostatic adjustment (GIA), potentially altering local nuclide production rates and, therefore, surface-exposure ages. Here we assess the impact of GIA on surface-exposure dating by calculating global time-dependent production rates since the Last Glacial Maximum using surface elevations that were corrected and uncorrected for GIA. We find that the magnitude of the GIA effect is spatially and temporally variable. Nuclide production could be reduced by up to 50% in the interior of large ice masses (in North America, Scandinavia and West Antarctica) at times of maximum glacial isostatic depression. Although smaller, the effect is still significant at ice sheet margins, where nuclide production is reduced by >5% and potentially >10%, making exposure ages older in those areas. Away from the ice sheet margins, land surfaces can be isostatically elevated, which can increase nuclide production by >5% and, therefore, make exposure ages younger. Areas that were more recently exposed or that are distal to large ice masses will generally be less affected. Importantly, we find that the effect at the primary 10Be production calibration sites is <1%. Applying a GIA correction to surface-exposure data may help resolve mismatches between some chronologies, but not necessarily in all regions, implying that additional factors may need to be considered. Past atmospheric changes can amplify or reduce the impact of GIA on nuclide production, and the combined effects should be fully accounted for in the future. These time-dependent influences on surface-exposure dating have potentially important implications for interpreting chronologies and for using the data to constrain ice sheet models. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet West Antarctica Durham University: Durham Research Online West Antarctica Quaternary Science Reviews 212 206 212 |
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Durham University: Durham Research Online |
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ftunivdurham |
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description |
Calculating cosmogenic-nuclide surface-exposure ages is critically dependent on a knowledge of the altitude of the sample site. Changes in altitude have occurred through time as a result of glacial isostatic adjustment (GIA), potentially altering local nuclide production rates and, therefore, surface-exposure ages. Here we assess the impact of GIA on surface-exposure dating by calculating global time-dependent production rates since the Last Glacial Maximum using surface elevations that were corrected and uncorrected for GIA. We find that the magnitude of the GIA effect is spatially and temporally variable. Nuclide production could be reduced by up to 50% in the interior of large ice masses (in North America, Scandinavia and West Antarctica) at times of maximum glacial isostatic depression. Although smaller, the effect is still significant at ice sheet margins, where nuclide production is reduced by >5% and potentially >10%, making exposure ages older in those areas. Away from the ice sheet margins, land surfaces can be isostatically elevated, which can increase nuclide production by >5% and, therefore, make exposure ages younger. Areas that were more recently exposed or that are distal to large ice masses will generally be less affected. Importantly, we find that the effect at the primary 10Be production calibration sites is <1%. Applying a GIA correction to surface-exposure data may help resolve mismatches between some chronologies, but not necessarily in all regions, implying that additional factors may need to be considered. Past atmospheric changes can amplify or reduce the impact of GIA on nuclide production, and the combined effects should be fully accounted for in the future. These time-dependent influences on surface-exposure dating have potentially important implications for interpreting chronologies and for using the data to constrain ice sheet models. |
format |
Article in Journal/Newspaper |
author |
Jones, R.S. Whitehouse, P.L. Bentley, M.J. Small, D. Dalton, A.S. |
spellingShingle |
Jones, R.S. Whitehouse, P.L. Bentley, M.J. Small, D. Dalton, A.S. Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
author_facet |
Jones, R.S. Whitehouse, P.L. Bentley, M.J. Small, D. Dalton, A.S. |
author_sort |
Jones, R.S. |
title |
Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
title_short |
Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
title_full |
Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
title_fullStr |
Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
title_full_unstemmed |
Impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
title_sort |
impact of glacial isostatic adjustment on cosmogenic surface-exposure dating. |
publisher |
Elsevier |
publishDate |
2019 |
url |
http://dro.dur.ac.uk/27776/ http://dro.dur.ac.uk/27776/1/27776.pdf https://doi.org/10.1016/j.quascirev.2019.03.012 |
geographic |
West Antarctica |
geographic_facet |
West Antarctica |
genre |
Antarc* Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctica Ice Sheet West Antarctica |
op_source |
Quaternary science reviews, 2019, Vol.212, pp.206-212 [Peer Reviewed Journal] |
op_relation |
dro:27776 issn:0277-3791 doi:10.1016/j.quascirev.2019.03.012 http://dro.dur.ac.uk/27776/ https://doi.org/10.1016/j.quascirev.2019.03.012 http://dro.dur.ac.uk/27776/1/27776.pdf |
op_rights |
© 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license(http://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.quascirev.2019.03.012 |
container_title |
Quaternary Science Reviews |
container_volume |
212 |
container_start_page |
206 |
op_container_end_page |
212 |
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1766248421409161216 |