The Indian Ocean - The World's Third Largest Ocean

The Indian Ocean and Trade in the Middle Ages

Europeans knew little about the Indian Ocean until in the middle ages they began to trade with the Arabs. Then they learned that spices grew on its coasts and islands, that pearls were found in its waters, that some of the lands bordering it had mines where precious stones were obtained, and that the people who lived near it made beautiful and valuable cloths of silk. No wonder the Europeans began to look for ways of reaching these lands. Vasco da Gama was the first to find a route round Africa in 1498 and Ferdinand Magellan crossed the Pacifc in 1522, thus opening a route to the Indian Ocean from the other direction.

The Indian Ocean is bordered by Africa on the west, India on the north and Australia on the east, but to the south there is open sea as far as the Antarctic. As in the Atlantic and the Pacifc, the surface waters move in two great eddies {that is, in two circular motions) one on either side of the equator. The southern currents move in an anti-clockwise direction, being driven by the trade winds westwards from Australia to Madagascar, where they turn south. They are then driven by the westerly winds (that is the winds coming from the west) from near the Cape of Good Hope eastwards to Australia, where they turn northwards to their starting point. The northern currents move anti-clockwise in winter and clockwise in summer, in both cases sweeping into the Bay of Bengal and the Arabian Sea.

The southern half of the Indian Ocean has few islands except Madagascar. Those in the northern half include Sri Lanka, Socotra and Mauritius, all of which are quite large, besides many small ones which are often made of coral with coconut palms round their shores. Two groups of these islands are between Madagascar and India. In the first are the Seychelles, Mauritius and Reunion, and in the second the Laccadive, Maldive and Chagos Islands.

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