Reconstructing sea-level change in the Falkland Islands (Islas Malvinas) using salt-marsh foraminifera, diatoms and testate amoebae

Thomas L. Newton, W. Roland Gehrels, Ralph M. Fyfe, Tim J. Daley*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Proxy records of past sea-level change provide a means of extending sea-level histories from tide gauges into the pre-industrial period. This is especially valuable in the South Atlantic region where sea-level data are limited to only a few tide-gauge records. Multi-proxy approaches to sea-level reconstruction are relatively rare but have distinct benefits when groups of micro-organisms are sparse or under-represented in modern or fossil sediments. Here, we address this challenge by utilising surface foraminifera, testate amoebae and diatoms from a salt marsh at Swan Inlet, East Falkland. All three micro-organism groups occupied distinct vertical niches in the contemporary salt-marsh. We investigated the relative performance of each group of micro-organisms in providing a sea-level reconstruction using individual (group-specific) regression models and with a multi-proxy regression model that combined all three groups. Foraminifera alone were not a suitable proxy. Surveyed sample elevations were closely matched by estimated elevations using Weighted-Average (WA) and Weighted-Average Partial-Least-Squares (WA- PLS) regressions. Relative sea-level reconstructions were derived by applying each model to microfossil assemblages recovered from a core (SI-2) from the same site. The combined transfer function yielded reconstructive precision (± 0.08 m) comparable to our best single-proxy transfer function (± 0.06 m) but only 18% of palaeo-samples were identified as having “close” or “good” analogues in the combined training data set. We highlight the benefit of a pragmatic approach to sea-level reconstructions whereby additional proxies should be employed if the use of only one proxy performs poorly across the width of the elevation gradient.

Original languageEnglish
Article number101923
Number of pages17
JournalMarine Micropaleontology
Early online date6 Oct 2020
Publication statusPublished - 1 Jan 2021


  • Falkland Islands
  • Sea level reconstruction
  • South Atlantic
  • Transfer functions

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