Script:
You will hear a talk on research on the Indian Ocean.
In this the first lecture in our series on the changing face of the oceans of the world, we are going to look at the Indian Ocean, into which the Oceanography Department at the Institute here in Australia has been doing pioneering research over the past five years.
Let us start with some facts about the Indian Ocean to give you an idea of the scope and complexity of the enterprise we have undertaken. As you can see from the diagrams here on the screen showing the relative size of the planet's five oceans, the Indian Ocean comes third after the Pacific and Atlantic Oceans, but is larger than the Southern Ocean and the Arctic Ocean.
On this slide you can see that the Indian Ocean is different from the two larger oceans in that it is landlocked to the north and does not extend into the cold regions of the North Pole. Covering some 73,440,000 sq km, the ocean constitutes approximately one-seventh of the earth's surface and about 20 percent of the world's total ocean area. At the equator it is around 6,400 km wide with the average depth being about 3,400 metres and with the deepest point being the Java Trench at 7,450 metres.
Flowing into the Indian Ocean we have some of the world's greatest rivers: the Zambezi here, the Ganges here, the Indus, The Bhrahmaputra and the Tigris-Euphrates just here.
The two largest islands in the Indian Ocean, Madagascar, here off the coast of Africa and Sri Lanka, here off the southern tip of India, are structurally parts of the continents of Africa and Asia, while islands like the Seychelles are exposed tops of submerged ridges. The Maldives are low coral islands and Mauritius and Reunion are volcanic cones.
The surface waters of the ocean are warm, except where the ocean touches the cold waters to the south. A network of scientists, mainly oceanographers and meteorologists, from around the world, are monitoring changes in the ocean's temperature and acidity, especially where it meets the Southern Ocean, in order to see how global warming is having an effect on the waters there. An assessment is also being carried out on how this is impacting on low-lying habitats and peoples in the more populated coastal regions around the rim of the ocean. In the warmer north, islands are vulnerable to even the subtlest changes in sea levels and tides, so they are being closely watched. Moreover, a close eye is being kept on wind changes, especially alterations to the monsoon rains, typhoons, cyclones and any other natural phenomena.
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