Salt-marsh reconstructions of relative sea-level change in the North Atlantic during the last 2000 years

Natasha L. M. Barlow, Antony J. Long, Margot H. Saher, W. Roland Gehrels, Mark H. Garnett, Rob G. Scaife

Research output: Contribution to journalArticlepeer-review

Abstract

Sea-level changes record changes in the mass balance of ice sheets and mountain glaciers, as well as dynamic ocean-atmosphere processes. Unravelling the contribution of each of these mechanisms on Late Holocene timescales ideally requires observations from a number of sites on several coasts within one or more oceans. We present the first 2000 year-long continuous salt marsh-based reconstructions of relative sea-level (RSL) change from the eastern North Atlantic and uniquely from a slowly uplifting coastline. We develop three RSL histories from two sites in north west Scotland to test for regional changes in sea-level tendency (a positive tendency indicating an increase in the proximity of marine conditions and a negative tendency the reverse), whilst at the same time highlighting methodological issues, including the problems of dataset noise when applying transfer functions to fossil salt-marsh sequences. The records show that RSL has been stable (±0.4m) during the last two millennia, and that the regional sea-level tendency has been negative throughout most of the record lengths. A recent switch in the biostratigraphy of all three records, indicating a regional positive tendency, means we cannot reject the hypothesis of a 20th century sea-level acceleration occurring in north west Scotland that must have exceeded the rate of background RSL fall (-0.4mmyr-1), but this signal appears muted and later than recorded from the western North Atlantic.

Original languageEnglish
Pages (from-to)1-16
Number of pages16
JournalQuaternary Science Reviews
Volume99
Early online date30 Jun 2014
DOIs
Publication statusPublished - 1 Sept 2014

Keywords

  • Climate
  • Diatoms
  • Foraminifera
  • North Atlantic
  • Salt marsh
  • Sea level
  • Transfer function

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