Classic models of the evolution of rocky coasts, like the one below, do not generally reflect the complexity of form on the rocky shorelines on Orkney. This is a reflection of the dominance of hydraulic action over abrasion in coastal erosion and also the variety of coastal configuration on Orkney.

Each of the main landform elements is locally well-developed but the assemblage of all these features is rarely seen. The main types of cliffed coast on Orkney are:

  1. high, vertical cliffs, with occasional stacks, which plunge into deep water, indented with geos and honey-combed with caves. Examples include The Nev and Quoy Geo.
  2. high, vertical cliffs with narrow boulder-strewn shore platforms, as around the Old Man of Hoy.
  3. low, drift-capped cliffs with geos and wide shore platforms but lacking stacks.

Loop of Crooie

  • The outer coast of Orkney is an outstanding location to study the erosion of hard rock coasts. Evidence of major erosion is not hard to find. The great bowl of Enegars corrie is losing its edge to the sea. The egg-shaped headland of Marwick Head is a dome half lost.

  • Amongst the many beauties of Orkney are the beaches which fringe the bays and ayres of the inner coast. These are dynamic forms, changing shape with the seasons and gradually retreating landward as sea level rises.

  • Orkney is a dissected landmass drowned by postglacial sea level rise. A drop in sea level of just 35 m would unite the archipelago into a single island. The individual islands may represent hills that formed the watershed areas of preglacial drainage basins but it is linear glacial erosion which has separated one island from another and severed Orkney from the rest of Scotland.

  • World coasts have seen sea-level variation of approximately 100 metres within the past 11,500 years through melting of the ice caps. When the ice caps melt the sea level rises globally (eustatically). The relative sea-level at any location is measured proportionate to the nearby land, which is itself subject to tectonic movement both up and down.