Salt-marsh testate amoebae as precise and widespread indicators of sea-level change
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record. Salt-marsh sediments are routinely used to reconstruct sea-level changes over past millennia. These reconstructions bridge an important gap between geological and instrumental sea-level r...
| Published in: | Earth-Science Reviews |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Elsevier
2016
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10871/30239 https://doi.org/10.1016/j.earscirev.2016.11.002 |
| Summary: | This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record. Salt-marsh sediments are routinely used to reconstruct sea-level changes over past millennia. These reconstructions bridge an important gap between geological and instrumental sea-level records, and provide insights into the role of atmospheric, oceanic, climatic and anthropogenic sea-level drivers, thereby improving understanding of contemporary and future sea-level changes. Salt-marsh foraminifera, diatoms and testate amoebae are three of the proxies capable of accurately reconstructing former sea level over decadal to millennial timescales. Datasets of surface assemblages are collated along elevational gradients to provide modern analogues that can be used to infer former marsh-surface elevations from fossil assemblages. Testate amoebae are the most recently developed proxy and existing studies suggest that they are at least as precise as the two other proxies. This study provides a synthesis of sea-level research using testate amoebae and collates and analyses existing surface datasets of intertidal salt-marsh testate amoebae from sites throughout the North Atlantic. We test the hypothesis that intertidal testate amoebae demonstrate cosmopolitan intertidal zonation across wide geographical areas in a way that is unique to this proxy. Testate amoebae assemblages are harmonised under a unified taxonomy and standardised into a single basin-wide training set suitable for reconstructing sea-level changes from salt-marsh sediments across the North Atlantic. Transfer functions are developed using regression modelling and show comparable performance values to published local training sets of foraminifera, diatoms and testate amoebae. When used to develop recent (last 100 years) sea-level reconstructions for sites in Norway and Quebec, Canada, the testate amoebae-based transfer function demonstrated prediction uncertainties of ± 0.26 m and ± 0.10 m respectively. These uncertainties equate to 10% and 11% ... |
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