EQ1

Question 1

assess whether the evidence supports the theory of plates tectonics (12 marks)

Answer 1

in this essay, I am going to talk about the theory of plate tectonics and whether the evidence supports it or not. Plates tectonics is the large movement of plate margin within the mantle and the earth. I partially think the evidence for the plate tectonics theory supports it.
Hess’ idea of seafloor spreading supports the theory of plate tectonics and the idea that the continents could actually drift apart. This is because it showed that oceans were shallower in the middle which it entitled the presence of mid ocean ridge. He found that the deepest parts of the ocean were very close to continental margins in the pacific with ocean trenches. An example that proves this idea is the mid Atlantic-Ridge. Hess’s idea was that oceans grew from their centre with basalt material oozing up the earth’s mantle along the mid ocean ridges. Therefore this creates new seafloor which then spreads away from the ridge in both direction. Hess believed that ocean trenches were the location where ocean floor was destroyed and recycled. Although his theory made a lot of sense, he still needed a lot of convincing geophysical evidence to support his idea and theory. Therefore we could say this evidence is partially true.

Wegener’s idea of continental drift supports the theory of plate tectonics. This is because it showed that the same type of fossilised plants and animals in South Africa and that the east coast of South America fits the West coast of Africa like a jigsaw puzzle. Also, Rock Formations and mountains chains match in south America and Africa and similar mineral deposits and natural resources such as coal exist along the west of Africa and the east coast of South America. Although this evidence is substantial and good, it does not explain why tectonics hazards like volcanoes are found many thousands of kilometres from the nearest plate boundary. Wilson, proposed that the mantle, forming volcanic island like Hawaii. He followed this discovery with the idea of a third plate boundary- transform faults. Transform faults were regarded as the missing piece in the puzzle of plate tectonic theory. An example that proves this idea is the San Andreas Fault between the North American and Pacific plates.
in conclusion

Question 2

explain why earthquakes and volcanoes have both a predictable, similar and yet different distribution(12)

Question 3

examine the contribution that convergent and divergent plate boundaries make to the magnitude of tectonic activity (12)

Question 4

assess the primary and secondary hazards created by volcanic activity (12)