Volcano's

Deep in the earth’s core it is exceedingly hot. It is so hot that rocks melts. The melted rock is called magma. The magma is lighter than the rocks around it so it rises. Sometimes it finds a crack or hole in the earth’s crust and bursts through. This is how a volcano begins.

A volcano is a mountain that forms when magma reaches the surface of the Earth.





**__What global effect do volcanic eruptions have? __** Volcanic eruptions have had a more global affect recently due to volcanic ash. As volcanoes erupt, they can produce lots of volcanic ash, and clouds of it can lead to breathing problems, malfunctions in machinery, and most importantly, it can clog up the air and cause air travelling problems. Volcanic Ash in the atmosphere will severely damage jet engines, and can cause global temperatures to decrease depending on quantity. Earlier on this year, Chile  Puyehue volcano erupted and strong winds carried the ash clouds more than 9334 kilometres across the Pacific Ocean to New Zealand and because of this, flights to and from New Zealand were cancelled. A lot of passengers were stranded in airports, until their flights could be rescheduled.

**__What is volcanic ash? __** Volcanic ash consists of tiny jagged pieces of rock and glass. Ash is hard, abrasive, mildly corrosive, conducts electricity when wet, and does not dissolve in water. Ash is spread over wide areas by wind.







The main reason for the eruptions from volcanoes is the heat deep within the Earth's layer. This heat slowly melts rocks to produce a slow moving substance called magma. Magma is lighter than the solid rock around it so magma rises and gathers in magma chambers. After a while the magma pushes through vents and cracks in the earth's surface. Then a volcanic eruption occurs! The magma comes out of the volcano and is now called lava. **Volcanic eruptions can be very dangerous… ** Some volcanic eruptions are dangerous and others are not. How explosive an eruption is depends on how runny or sticky the magma is. If magma is thin and runny, gases can break out easily from it. When this type of magma erupts, it flows out of the volcano. Lava flows hardly ever kill people, because they move slowly enough for people to get out of their way. Lava flow, however, can cause considerable damage to buildings in their path. If magma is thick and sticky, gases cannot break out easily. Pressure builds up until the gases escape aggressively and explode. In this type of eruption, the magma blasts into the air and breaks apart into pieces called tephra. Tephra can range in size from tiny particles of ash to house-size boulders. Explosive volcanic eruptions can be dangerous and deadly. They can blast out clouds of hot tephra from the side or top of a volcano. These flaming clouds race down mountainsides destroying almost everything in their path. Ash erupted into the sky falls back to Earth. If thick enough, blankets of ash can choke plants, animals, and human beings. When hot volcanic materials mix with water from streams or melted snow and ice, mudflows form. Mudflows have buried entire communities located near erupting volcanoes.





Volcanoes and earthquakes are strongly related. For example, if you look at a map of earthquakes around the planet and compare it to a map of volcanoes, you'll see that they match closely. Both earthquakes and volcanoes happen at the boundaries of tectonic plates, which make up the Earth's surface.

Earthquakes are caused by the release of pressure built up when the plates spread apart or move past each or under each other. In slightly more complex ways, magma is generated at most plate boundaries and this magma rises to the surface to form volcanoes.




 * The different landforms formed by volcanic eruptions? **

A crater lake is formed by a volcanic crater, a big hole in the ground, which was formed by volcanic activity. Some crater lakes that are on active volcanic vents can be called volcanic lakes, the water on these lakes are often acidic and a greenish colour. Crater lakes that are located on dormant volcanoes have usually had fresh water.
 * **<span style="font-family: 'Century Schoolbook','serif'; font-size: 35px;">Crater lakes ** ||

<span style="display: block; font-family: 'lucida console',monaco,monospace; font-size: 120%; text-align: justify;"> //<span style="font-family: 'Century Schoolbook','serif';">Location (below) : Crater Lake and Wizard Island, Crater Lake National Park, Oregon, USA //



<span style="display: block; font-family: 'lucida console',monaco,monospace; font-size: 120%; text-align: center;"> **<span style="font-family: 'Century Schoolbook','serif'; font-size: 35px;">Geysers **

<span style="display: block; font-family: 'Century Schoolbook','serif'; font-size: 120%; text-align: justify;">A geyser is a vent in Earth's surface that regularly ejects an amount of hot water and steam. Even a small geyser is an amazing experience; but in some cases some geysers have eruptions that blast huge amounts of boiling hot water up to an amazing distance in the air. <span style="display: block; font-family: 'lucida console',monaco,monospace; font-size: 120%; text-align: justify;"> //<span style="font-family: 'Century Schoolbook','serif';">Location (Below): Strokkur geyser, Iceland //

<span style="display: block; font-family: 'lucida console',monaco,monospace; font-size: 120%; text-align: justify;">**<span style="font-family: 'Century Schoolbook','serif'; font-size: 35px;">Lava tubes ** <span style="display: block; font-family: 'Century Schoolbook','serif'; font-size: 120%; text-align: justify;">A lava tube is a cave which lava once flowed through creating a long cave like tube. Lava tubes form by the crusting over lava channels. Once the lava has stopped flowing, long tunnels are left behind. <span style="display: block; font-family: 'lucida console',monaco,monospace; font-size: 120%; text-align: justify;"> //<span style="font-family: 'Century Schoolbook','serif';">Location (below): Thurston Lava Tube in Hawaii Volcanoes National Park, Hawaii. //





<span style="font-family: 'Century Schoolbook','serif'; font-size: 19px; text-align: justify;">Volcanic eruptions cover roads, houses, buildings and fields with ash, sometimes it is impossible to breathe when the ash fall is so heavy. Part of the volcano can collapse at any moment so that would affect the people living on the flank of the volcano, gases are then released which can kill all the plants, and make it harder to breathe. <span style="font-family: 'Century Schoolbook','serif'; font-size: 19px; text-align: justify;"> V<span style="font-family: 'Century Schoolbook','serif';">olcanic eruptions bury the earth in mud or lava, if you were caught is this circumstance then you would surely be killed. If a plane flew past it would not be able to see through the smoke, electric power lines are not served well by the lava, as pyroclastic flows ( fluidized masses of rock fragments and gases that move) <span style="font-family: 'Century Schoolbook','serif';">muck up the system, cars are covered in ash, and water becomes to acidic for boats to be able to cross the sea, because the acidic water would burn the boat right through.

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