Coast Erosion in Northeast Ireland:-Part II Cliffs and Shore Platforms

Abstract

This paper summarises the erosion of the ‘hard’ coast (cliffs and shore platforms) of northeast Ireland, between Portstewart, Co. Londonderry and Larne. Co. Antrim. Although there is abundant evidence of localised coastal changes, it is not possible to define rates of erosion except on the glacial material cliffs at Portballintrae. where a mean rate of 0.25m/year (1949- 1987) was recorded, although this mean rate appears anomalous in a longer term perspective. Elsewhere, marine erosion is confined to occasional block falls or block dislodgement. Undercutting of cliffs also helps to trigger a variety of sub-aerial slope failures ranging from small superficial slides to large landslips. Patterns of marine erosion are linked to lithological variations in the rock, with the most resistant material (Cretaceous chalk) showing no discernible changes over the last 100 years. The construction of the Antrim Coast Road (A2) in the 1800s has led to the disruption of littoral sediment supplies along stretches of the east coast, and may be associated with vulnerability to shoreline erosion, and the constant need to reinforce coastal defenses. Management requirements of the Co. Antrim cliffs are limited, but due consideration should be given to the problems of accessibility, cliffs and rock-fall hazards.

Keywords:

• Coastal cliffs
• shore platforms
• erosion
• Ireland