Exemplar (37 Marks)-“Volcanic and Seismic events are major pieces of evidence towards proving that plate tectonics theory is valid” Discuss the extent to which you agree with this statement. (40 Marks)
The theory of plate tectonics is a relatively new idea – only conceived and developed within the last 100 years and is now generally accepted as the explanation for the causation of earthquakes and volcanoes and where they occur. It has now replaced the theory that tectonic events are caused by god in most western countries. The theory of plate tectonics was first developed by Alfred Wegener in 1912. He saw that the continents seem to have a jig-saw fit e.g. Africa and South America coastlines fitting together, suggesting that they were at one time joined together as part of a super continent called Gondwanaland and the other super continent Laurasia was in the north. Later evidence supported this – the fossilised remains of a dinosaur, the mosasaurs, was found on the coasts of Brazil and Gabon. There were also the same fossilised pollen species and rock sediments on these coastlines.
Wegener’s ideas, though simple, were proved further right and built upon which further increased our understanding of tectonic events. Sea floor spreading was discovered showing that rock is being created and destroyed, leading us to believe in the existence of plates and plate boundaries. Sea floor spreading was shown in the Atlantic, where it is believed the Eurasian and North American plates are moving apart, at what is called a constructive plate boundary. Here magma rises through a rift and cools rapidly on the surface creating new plate material and a ridge of volcanoes called the mid-Atlantic ridge. This has created Iceland which also contains rift valleys showing the plates are moving apart. The eruption of Surtsey in 1963 created a new island which further proved that land