The Eyjafjallajokull volcano in Iceland has been erupting for the last few weeks, but over recent days has been sending massive clouds of volcanic ash into the sky, which has been disrupting air flights across the UK.
What is a volcano
- A volcano is an opening, or rupture, in the Earth’s surface which lets hot magma (molten rock from within the planet’s crust), ash (finely powdered rock that looks like dark smoke) and gases escape from below the surface.
- Lava is what we call magma when it erupts – it can be thick and slow-moving or thin and fast-moving and ranges from 700 degrees to 1,200 degrees Celsius in temperature, glowing red hot to white hot as it flows.
- It’s thought the word “volcano” comes from the name of Vulcano, an island off Sicily named after Vulcan, the Roman god of fire.
- Volcanoes are generally found where tectonic plates diverge (pull apart) or converge (come together). But they’re usually not created where two plates slide past each other.
- There are around 1,500 “active” volcanoes in the world, 80 or more of which are under the oceans.
- The Ring of Fire is a belt around the Pacific Ocean where more than half of the world’s volcanoes arise.
- Hawaii’s Mauna Loa is the largest volcano on the planet, standing six miles tall from the sea floor to its summit.
- In the wider solar system, Mars is believed to hold the honour of housing the largest volcano – the 17-mile tall Olympus Mons.
Why are plane flights being affected?
- Volcanic ash is very dangerous to planes; it contain lots of bits of rock which can damage planes, stops the pilot from seeing clearly and can clog the engines and landing gears.
- Sometimes aircraft many miles from the scene of an eruption can be in danger, with giant plumes of ash rising high into the sky and then travelling vast distances.
- When Mount St Helens erupted in Washington state in America in 1980 the plume reached as high as 90,000ft in just 30 minutes. In 15 hours, it had travelled 600 miles downwind and within two weeks ash had circled the earth.
- One of the biggest difficulties facing flight crews is the problem of distinguishing ash clouds from ordinary clouds, both visually and on radar.
Click below to see images from the Eyjafjallajokull volcano in Iceland