The Ocean 



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separates the Cape Basin from the Angola Basin, forms a continuous diagonal 

 transverse barrier. It rises steeply from a depth of 5000-5500 m to only 964 m, 

 forming an unbroken submarine wall connecting the mid-Atlantic Ridge between 

 Tristan da Cunha and Gough Island with the broad shelf of the African mainland. All 

 the other ridges in the east Atlantic trough have openings that reach below 4000 m. 



{b) Indian Ocean 



It is only in more recent times that it has been found that the Indian Ocean is also 

 divided into two large troughs by a central ridge. This central ridge runs north- 

 westward from the Kerguelen-Gaussberg Ridge, gradually narrowing, then through 

 the elevation around the volcanic islands of New Amsterdam and St Paul in the section 

 between the 20° and 0°, where it reaches its highest elevation. Here it carries the shallow 

 waters and banks of the Saya da Malha and the Nazareth Bank. Two outlying ridges 

 run out from this point, one to the north-west to the Seychelles and the Amirantes, 

 and the other to the south-west, here it carries the islands of Mauritius and Reunion. 

 In this middle section the ridge stretches over more than 10° of latitude. From here it 

 splits into two parts running towards the north. The eastern part carries the Chagos 

 Islands and runs up through the Maldives and the Laccadives, gaining a connection 

 to the south-west Indian shelf. The western part, which was first mapped by the 

 Danish "Dana" Expedition (Carlsberg Ridge), is much narrower and not as high. 

 This Indian Ridge is also of enormous length and runs from the South Arabian Sea 

 to the edge of Antarctica at Kaiser Wilhelm Land (WusT, 1934). 



