Swan, Lionel D., McCarthy, Gerard D. and Bergin, Claire (2026) Investigating the occurrence of an unusual tidal event along the north–west coast of Ireland. Natural Hazards, 122 (517). pp. 1-22. ISSN 0921-030X
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Abstract
The study investigates the occurrence of an unusual tidal event recorded at Portsalon Golf Club on 21st February 2022 at 08:50 UTC. The event followed the passage of Storm Franklin and was described by the videographer as a “rather unusual storm surge”, prompting the evaluation of multiple event types to identify the most likely cause: Storm Surge, High-Tide Seiching, Freak Wave, Meteotsunami or Tsunami. Through the use of 5-min tidal observations, 1-min meteorological station data and ERA5 reanalysis products, sea-level and atmospheric variability and synoptic conditions prior to and during the videoed event were examined. Results highlight evidence of elevated non-tidal variability coinciding with strong winds and high wave height (~ 12 m) near the mouth of Lough Swilly following the passage of Storm Franklin. Oscillations recorded at Letterkenny tidal gauge on the approach to high tide suggest the possibility of seiching within Louch Swilly. Background conditions often associated with Meteotsunamis, such as the presence of a strong jet stream and area of high relative humidity, were present, however no clear or particularly rapid atmospheric pressure disruption was found that temporally aligned with the observed wave. Neither the prevailing wind or wave direction suggested a freak wave was a contributing factor, and no spatially or temporally relevant seismic activity was recorded. The most likely explanation of the videoed event is the combination of a weakening storm surge amplified by high-tide seiching in Lough Swilly. Limitations in analysis highlight the need for higher-frequency coastal monitoring to aid the classification of such hazards.
| Item Type: | Article |
|---|---|
| Additional Information: | Open Access funding provided by the IReL Consortium. This study is ObsSea4Clim contribution nr. 46. ObsSea4Clim “Ocean observations and indicators for climate and assessments” is funded by the European Union, Horizon Europe Funding Programme for Research and Innovation under grant agreement number: 101136548. GM is additionally supported by the A4 Project (Aigéin, Aeráid, agus athrú Atlantaigh), with the support of the Marine Institute, under the Marine Research Programme, funded by the Irish Government Grant PBA/CC/18/01) and by iCRAG, with the support of Science Foundation Ireland (Grant 13/RC/2092_P2). LS and CB are supported by the Weather Attribution Science Irish operaTional User Service (WASITUS) Project, funded by the EPA and Met Éireann, Project Code [2024-CE-1265]. |
| Keywords: | Meteotsunami; Storm surge; High-tide seiching; Lough Swilly; Ireland; |
| Academic Unit: | Faculty of Social Sciences > Geography Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS |
| Item ID: | 21776 |
| Identification Number: | 10.1007/s11069-026-08287-3 |
| Depositing User: | ICARUS Geography |
| Date Deposited: | 18 Aug 2026 14:22 |
| Journal or Publication Title: | Natural Hazards |
| Publisher: | Springer |
| Refereed: | Yes |
| Related URLs: | |
| Use Licence: | This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here |
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