This is our second KS3 Geography quiz on earthquakes and volcanoes. Earthquakes are measured with a seismometer which measures their magnitude. There are earthquakes every few days in the UK, but most are very small, with a magnitude of 2 or less. A magnitude of 3 or lower is rarely noticed by anyone and only about 20 per year are felt by people. In other parts of the world, where the Earth's plates are moving relative to each other, much larger earthquakes can happen. An earthquake with a magnitude of 7 can cause serious damage over large areas. A magnitude 9 earthquake is extremely destructive.
One of the pieces of evidence that was used to discover that the Earth's crust was broken into moving plates was first suggested at the start of the twentieth century. A German scientist named Alfred Wegener noticed that the coastlines and some rock formations of south America and Africa seemed to match together reasonably well. This suggested to him that the two continents had once been joined together. Further evidence comes from volcanoes. When the world's active volcanoes are marked on a map, they seem to appear only in narrow, well-defined areas. We now know that this is where the crustal plates meet.
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You can find more about this topic by visiting BBC Bitesize - Disasters and responses
The mantle is a much thicker layer than the crust
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Currents in the mantle are thought to be what move the crustal plates
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Known as the 'Pacific Ring of Fire'
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At the time of writing this quiz, the world's strongest recorded earthquake was magnitude 9.5. It occured in the Pacific Ocean near Chile in 1960
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The edges of plates are very unstable areas - rocks don't move past each other very easily!
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They split apart as the earth's plates moved, forming the Atlantic Ocean
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Hawaii has a national park called 'Volcanoes'
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All the volcanoes in the British Isles are extinct. Phew!!
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Probably the best known geyser is 'Old Faithful' which is in Yellowstone National Park in the USA
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They can be thrown hundreds of feet in the air and are very dangerous to people and buildings near to an eruption
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