A look at the world-map gives the idea that continents and oceans are the principal surface features of the globe. It is also observed that there is a remarkable accumulation of landmasses in the northern hemisphere whereas in the southern hemisphere there is appreciable concentration of water bodies.
It is also noticed that majority of the continents have southerly tapering ends. Besides, while the north pole is located in the Arctic-ocean, the south pole is located in the continent Apart from the aforesaid observations, it is also important to notice that continental boundaries on either side of the Atlantic-ocean match with each other.
All these observations usually give the impression that the continents might once have been joined but then split apart and moved away from one another as a result of which the present day arrangement of continents and oceans has been developed.
Continental-drift refers to the horizontal movement of the continents on a vast-scale. The idea of moving continents is not new. The notable observations as already mentioned prompted study and speculation by earth-scientists.
ADVERTISEMENTS:
The similarities in shape of the Atlantic coastlines of South America and Africa were noticed by Francis Bacon in 1620. In 1858 Antonio Snider showed on maps how these continents might have once been joined and then split apart in later times to form the present-day continents and oceans.
In the late nineteenth century, a famous Austrian geologist, Edward Suess, suggested that ail the southern-hemisphere continents, together with India, were once assembled into a single large landmass which he called Gondwanaland.
His idea was based on the similarity of certain geological formations from continent to continent. In 1908, it was F.B. Taylor who propounded the Continental-drift hypothesis, incorporating much other geological evidences.
In 1910 and 1912, Alfred Wegener, a German meteorologist, advocated that continents had drifted apart and suggested mechanisms by which this might have occurred.