NOMENCLATURE AND CLASSIFICATION OF DEEP-SEA RELIEF
Before the advent of continuously recorded echo-sounding profiles, and their revelation of the texture of the sea-floor relief, classification and nomenclature of submarine topography were based on broad closed isobaths. We can characterize the older system as the bathymetric system of nomenclature in contrast to that employed in this paper, which we can call a geomorphic or textural system.
The terms "basin" and "deep" used in the older literature are usually defined by closed 3000-, 4000-, or 5000-meter contours as represented on the Carte Générale Bathymétrique des Océans (International Hydrographic Bureau). For many purposes this terminology is useful, particularly in describing the habitat of a deep-sea fish or the locale of a water mass. Consequently some such system should be retained even though in many areas basin boundaries are difficult to define, and regardless of the fact that many boundaries cut arbitrarily through physiographic provinces without regard for local province boundaries. The Atlantic has been subdivided by Wüst (1940b) (Fig. 4) whose system is now in general use.
Figure 4.—Major basins of the North Atlantic, after Wüst (1940)
Heavy solid lines indicate boundary formed by axis of Mid-Atlantic Ridge. Light solid lines indicate boundary formed by shelf breaks and submarine ridges. Dashed lines indicate arbitrary boundaries.
The nomenclature of deep-sea topography has been considered by several committees during the past half century. The most recent recommendations published by Wiseman and Ovey (1953; 1955) are followed wherever applicable. The older systems of nomenclature, however, are not rigidly employed since we are dealing with textural provinces based on profiles obtained with continuously recording echo sounders rather than bathymetric provinces defined by closed isobaths.