Raised coastal landforms as products of modern process variations, and their relevance in eustatic sea‐level studies: examples from eastern Ireland

Abstract

Products of marine processes occupy a considerable vertical range, which varies along the shore. Extreme waves can both cause erosion and form depositional structures up to several metres above the high tide mark. Temporary supra‐elevation of water level by surge or wave set‐up shifts effects upward. The preservation potential of products of extreme storms is relatively high, when compared to those associated with more frequent events. The level to which coastal landforms develop depends upon the conditions under which they form; thus sand beach ridges which are related to fairweathcr periods have a restricted height range when compared to gravel beach ridges building up under extreme storms. The varied coastal scenery of eastern Ireland provides many examples of storm‐related products (barriers. cliffs, platforms, etc.). They have been related to a latc‐Holocene eustatic sea level or even a partly isostatically controlled raised late‐Holoccne sea level, but both elevations and apparent tilts can be explained by longshore variations in waves, tides and surges. Such an explanation is more consistent with other studies of latc‐Holocene coastal evolution around the Irish Sea basin.