Examine how humans interact with the rock cycle, with reference to mining, quarrying, oil and gas exploration, or geothermal energy production

A major interaction with the rock cycle I have studied is the development of geothermal energy in Iceland. Geothermal energy uses heat from igneous rocks to heat water and generate steam to produce electricity. Many developed countries, such as New Zealand and Japan, are leaders in the development of these geothermal energy schemes.

Iceland is on the Mid-Atlantic Ridge, a divergent plate boundary where the North American and Eurasian plates are separating. Molten magma rises close to the surface and thus very high temperatures occur here. This results in the heating of groundwater. Alternatively, cold water can be pumped near the heated rocks and back up to the surface as heated water, where it is then pumped to the capital of Reykjavik. The hot water is used to heat offices, apartments and even the footpaths. It may also be used to heat greenhouses and produce fruit and vegetables in this cold boreal climate, thus reducing Iceland’s imports of food.

At geothermal power plants, the water is at very high temperatures and turns to steam, which is used to generate electricity. Nearly 30% of Iceland’s electricity comes from this cheap, clean, and renewable source of energy. Expensive imports of much dirtier fossil fuels have been dramatically reduced and Reykjavik is now the cleanest capital city in the western world.

Tourism to Iceland has also increased due to many visitors coming to see the Blue Lagoon, an outdoor geothermal spa. The spa is a man-made lagoon fed by the output of excess water from a nearby geothermal power station. The water is rich in minerals like sulphur and silica which are excellent in the treatment of arthritis and some skin diseases. Over 400,000 tourists visit the spa annually bringing revenue to this country of just 320,000 people. Many hotels, providing much needed employment, have been built near the spa to cater for the rapidly growing tourist industry. It is envisaged that surplus electricity may soon be exported to the UK, bringing in even more revenue.