Sea-level Changes During the Holocene: The North Atlantic and Arctic Oceans

Abstract

The North Atlantic and Arctic oceans encompass a large (50.3M km²) and, in relation to Late Quaternary isostatic movements, a structurally dynamic zone of the earth’s crust. Although difficult to define perhaps as a regional unit, the southern boundary of this zone may be placed arbitrarily at approximately Lat. 30ºN (Fig. 10.1). Waters north of this line generally have a high turbidity and are characterised by mean annual surface temperatures of ~ 20ºC, resulting in a lack of the coral reefs so typical of shallow water zones in the Pacific and Indian oceans. Coastlines north of 40ºN are also dominated by meso- to macrotidal, high energy storm wave conditions, with lower energy swell wave mesotidal coasts occurring southward (Fig. 10.1) (Davies, 1980). Further distinctiveness is given to this region in two important respects. Firstly, in terms of sea-level research, the North Atlantic forms one of the most intensively studied of the earth’s oceans. Most perhaps is known about conditions here during the Holocene and coastal-offshore areas retain some record, often a detailed one, of environmental changes from this time. Analyses of the data from this and earlier geological stages have given rise to many of the major concepts conditioning our current understanding of the processes and patterns of sea-surface changes. Secondly, the Quaternary history of the North Atlantic-Arctic oceans, together with their continental margins, has been distinctively influenced by the build-up and decay of the major Northern Hemisphere ice masses.