Sunday, March 30, 2014

Continents


A little less than one-third of the earth’s surface is land mass and the rest is covered by water. There are seven large continuous land masses called continents. They are: Asia, Europe, Africa, North America, South America, Australia and Antarctica.



            According to the German geologist, Alfred Wegener, once the earth was a single land mass known as Pangaea. Nearly 200 million years ago this land mass broke into two parts- Laurasia and Gondwana land.

            According to Wegener’s continental drift theory, these two large land masses continued to drift away from each other. Present North America and Eurasia Europe and Asia emerged out of Laurasia, while the South America, Africa, Australia and Antarctica owe their existence to the Gondwana land. Thus the seven continents of the world appeared.

            The theory also explains that not only the continents but also the crust plates, which include both the continents and the oceans, drift. Thus the continents are undergoing changes even now. In fact, earthquakes are also caused due to the drifting of these crust plates. Reference: Children’s Science Library by A.H.Hashmi.

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