South African Coastal Waters in Relation to Ocean Currents
1937; Taylor & Francis; Volume: 27; Issue: 4 Linguagem: Inglês
10.2307/209863
ISSN1931-0846
Autores Tópico(s)International Maritime Law Issues
ResumoIT has long been known that the coasts of South Africa are subject to the influence of warm and cold ocean currents, the former along the east and south coasts, the latter along the west coast. From the navigator's point of view much information exists concerning the warm current; but data relating to the influence of both the warm and the cold currents on the coastal waters of South Africa are meager and scattered. A popular view that the Cape of Good Hope marks the division of the currents is incorrect both in that most of the warmcurrent water does not extend so far and in the over-simplification of a somewhat complicated current system. The direction of the currents round the coast is affected more by the margin of the continental shelf than by the coast line itself. The limit of the continental shelf in Africa is not far from the coast line for most of its extent. In the region of Cape Agulhas, the southernmost point of the continent, there is, however, an extensive area of shallow water, known as the Agulhas Bank. The map shown in Figure i-reduced from the British Admiralty chart of the Indian Ocean in current use, which itself is based on a chart drawn up by Rear Admiral Richards in i87o-indicates II5 miles as the maximum extent of the Agulhas Bank beyond the limits of the land. At the longitude of Cape Agulhas the bank extends southwards for about 8o miles. On the map the limits of the bank are left indefinite; but for the purposes of navigation it is regarded as tapering off much more to the west than the chart suggests. For practical purposes its eastern limit may be placed in the region of Knysna.1 The existence and extent of the Agulhas Bank have been recognized since early times, as is evidenced by Blaeu's map of /E:thiopia Inferior published about I650, in which the bank is represented with tolerable accuracy. It also appears on Hondius' map of i6o6, on which, however, it is shown as of very small proportions.
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