lectricity.
             2. Soils produced from the ash and weathered rocks of volcanic eruptions are extremely fertile and flanks of large volcanoes are often used for agriculture.
             3. On the island of Lanzarote, to the west of Africa, the locals use volcanic rocks for building stone; its readily available, cheap and there are very few other building materials. It is also light so easy to transport but not very strong so buildings can't be very tall - which is great if you don't want to ruin your skyline with skyscrapers!
             4. Volcanic eruptions themselves have been important in geological history by introducing gases into the Earth's atmosphere, in particular water vapour, sulphur, carbon dioxide and carbon monoxide. These gases have played an important role in the development of our atmosphere.
             5. Tourism - many volcanic areas are exploited for tourism e.g. trips to Vesuvius and Mt Etna in Italy. The volcanoes and hydrothermal areas of New Zealand and Hawaii also attract many tourists.
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