2.3
Distribution of the Oceanic
Regions
I have combined and rearranged the 12 regional
divisions to identify oceanic regions. The
resulting ecoregion divisions are shown diagrammatically in Fig. 2.6 as they might appear
in a hypothetical ocean basin. On the diagram
12 kinds of regional divisions are recognized.
They range from the inner polar division at high
latitudes to the equatorial countercurrent division at low latitudes. Two of them are further
subdivided (not shown on diagram) on the basis
of high salinity following work by Elliott
(1954).
I further simplified this classification of oceanic regions, using some of Schott’s ideas (1936,
as reported by Joerg 1935), by grouping the
divisions in larger regions, called domains
(Fig. 2.6). This recognizes the fact that the oceanic regions are arranged in latitudinal belts
which reflect the major climatic zones. In both
hemispheres there are three contrasting types of
water, differing in temperature, salinity, life
forms, and color. They are separated along the
major lines of convergence where surface
currents meet. In the high latitudes are the polar
waters, characterized generally as low in temperature, low in salinity, rich in plankton, and greenish in color. These currents, also, frequently carry
drift ice and icebergs. In the low latitudes are the
tropical waters, generally high in temperature,
high in salinity, low in organic forms, and blue
in color. In between lie the so-called mixed
waters of the temperate, middle latitudes.
As in the case of all phenomena on the Earth’s
surface that are directly or indirectly related to
the climate, there is a tendency toward regularity
in the pattern of arrangement of the hydrologic
zones. However, the distribution of these various
kinds of ocean water and the convergences that
separate them is not strictly latitudinal. The east
coasts of the continents are bathed by polewardmoving currents of tropical water. The west
coasts at the same latitudes are bathed by colder
waters moving from the poles. Because of the
configuration of the ocean basins, the warm, eastcoast currents of the Atlantic and the Pacific
Oceans are best developed in the Northern Hemisphere, and the cold, west-coast currents in the
Southern Hemisphere. As mentioned above,
Fig. 2.6 Ecoregion domains and divisions in a hypothetical ocean basin. Compare with ocean map, Plate 1
2.3 Distribution of the Oceanic Regions
15
Distribution of the Oceanic
Regions
I have combined and rearranged the 12 regional
divisions to identify oceanic regions. The
resulting ecoregion divisions are shown diagrammatically in Fig. 2.6 as they might appear
in a hypothetical ocean basin. On the diagram
12 kinds of regional divisions are recognized.
They range from the inner polar division at high
latitudes to the equatorial countercurrent division at low latitudes. Two of them are further
subdivided (not shown on diagram) on the basis
of high salinity following work by Elliott
(1954).
I further simplified this classification of oceanic regions, using some of Schott’s ideas (1936,
as reported by Joerg 1935), by grouping the
divisions in larger regions, called domains
(Fig. 2.6). This recognizes the fact that the oceanic regions are arranged in latitudinal belts
which reflect the major climatic zones. In both
hemispheres there are three contrasting types of
water, differing in temperature, salinity, life
forms, and color. They are separated along the
major lines of convergence where surface
currents meet. In the high latitudes are the polar
waters, characterized generally as low in temperature, low in salinity, rich in plankton, and greenish in color. These currents, also, frequently carry
drift ice and icebergs. In the low latitudes are the
tropical waters, generally high in temperature,
high in salinity, low in organic forms, and blue
in color. In between lie the so-called mixed
waters of the temperate, middle latitudes.
As in the case of all phenomena on the Earth’s
surface that are directly or indirectly related to
the climate, there is a tendency toward regularity
in the pattern of arrangement of the hydrologic
zones. However, the distribution of these various
kinds of ocean water and the convergences that
separate them is not strictly latitudinal. The east
coasts of the continents are bathed by polewardmoving currents of tropical water. The west
coasts at the same latitudes are bathed by colder
waters moving from the poles. Because of the
configuration of the ocean basins, the warm, eastcoast currents of the Atlantic and the Pacific
Oceans are best developed in the Northern Hemisphere, and the cold, west-coast currents in the
Southern Hemisphere. As mentioned above,
Fig. 2.6 Ecoregion domains and divisions in a hypothetical ocean basin. Compare with ocean map, Plate 1
2.3 Distribution of the Oceanic Regions
15