Science Week 2015: The west coast of Ireland: why is it a surfer’s paradise?
10 November 2015
The west coast of Ireland: why is it a surferís paradise?
Exposed to the wild North Atlantic Ocean, the west coast of Ireland boasts some of the best surfing in Europe. In recent times, the popularity of surfing in Ireland has increased greatly, with surfers from all over the world visiting our shores. Some of the most famous big-wave spots are Mullaghmore, Co. Sligo and the Cliffs of Moher, Co. Clare. So what makes the west coast of Ireland such a good place to surf?
When depressions form in the North Atlantic, winds blow across the surface of the ocean, creating larger and larger waves. These waves (the swell) then begin propagating eastwards towards Europe. The best surfing waves are created when an energetic storm combines with the underwater topography, or bathymetry. Bathymetry is a scientific term to denote the water depth.† As the swell propagates towards the coastline, waves start to feel the effects of the sea floor. In the near-shore, waves can be amplified locally by the bathymetry when there is a steep ascent of the sea floor. This is precisely what happens on the west coast of Ireland.
Figure 1: Surfer on a large wave, Mullaghmore, Co. Sligo on 06 January 2014. (Photo: Sarah Gallagher)
Ireland has a long history of large storm waves. The most common measure of ocean wave heights is given by the significant wave height, which represents the mean wave height (trough to crest) of the highest one-third of the waves (see Figure 2). The World Meteorological Organization (WMO) defines significant wave heights greater than 14m as a phenomenal sea-state. Studies have shown that the significant wave height can frequently exceed 14m off the west coast of Ireland . †
Figure 2: Each wave form has a wave crest, trough, height, and wavelength. By Julie Sandeen [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons.
The highest significant wave height measured off the coast of Ireland was 17.2m, recorded on 09 December 2007 at the M6 wave buoy. The highest individual wave (trough to crest) recorded was 25m, measured at the Kinsale Energy Gas Platform on 12 February 2014. How many other monster waves might there be in the future?
 Gleeson, E., McGrath, R. and Treanor, M. 2013. Irelandís Climate: The Road Ahead. Dublin, Met …ireann.