On the varied impact of the Storegga tsunami in northwest Scotland

Sarah A. Woodroffe*, Jon Hill, Emmanuel Bustamante-Fernandez, Jerry M. Lloyd, Jake Luff, Sarah Richards, Ian Shennan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

In this paper we evaluate new data and those from previous studies in northwest Scotland and perform a modelling study to test the hypothesis that the Storegga tsunami (submarine slope failure off the continental shelf of Central Norway dated to 8120–8175 bp) impacted this region. The model used is a 2D non-linear, non-conservative, Shallow Water Equation solver incorporating inundation and realistic glacial isostatic adjustment-corrected palaeobathymetry, with horizontal resolution down to 30 m at sites of interest. The 15 coastal study sites analysed range from south of the Isle of Skye to Assynt. We predict run-up between 2.7 and 9.4 m above contemporaneous mean tide level across the region, with the highest on the west coast of the Outer Hebrides, the east coast of Skye and at the head of long sea lochs east of Skye. We re-evaluate evidence from previously studied open coastal marshes, isolation basins and barrier locations for the tsunami and suggest that in many locations the Storegga tsunami is the most likely cause of erosion, deposition and changes in microfossil assemblages in the early Holocene. The predictions of wave height and inundation produced by the tsunami modelling fit well with the range of available field evidence in the region. We predict significant wave heights at least as far south as Mull on the west coast.

Original languageEnglish
Number of pages14
JournalJournal of Quaternary Science
Early online date30 May 2023
DOIs
Publication statusE-pub ahead of print - 30 May 2023

Bibliographical note

Publisher Copyright:
© 2023 The Authors Journal of Quaternary Science Published by John Wiley & Sons Ltd.

Keywords

  • coastal basins
  • microfossils
  • NW Scotland
  • Storegga
  • tsunami

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