Volcano Formation

From GeoClasses

1 Summmary
2 What is a Volcano?
3 How are Volcanoes formed?
4 What is a hot-spot?
5 What are the different types of Volcanoes?
6 References

Summmary

What is a volcano? How are volcanoes formed? What is a hot-spot? What are the different types of volcanoes? These are just a few of the questions that people commonly have about volcanoes. The purpose of this current research is to answer all of the question listed above.

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What is a Volcano?

According to wikipedia.com a volcano is an opening,or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.

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How are Volcanoes formed?

A volcano forms when hot molten rock (called magma while it's still underground) erupts at the surface. Molten rock on the surface is called lava and it will build up around the vent where it comes out, forming a volcano. There is also almost always a lot of gas within the magma. When it gets to the surface it expands rapidly and sometimes explosively (like releasing the pressure on a soda). This produces pyroclastic material (material that is thrown into the air from the vent). Pyroclastic material can be fine or coarse, but either way it will also pile up around the vent, helping to build the volcano. Most volcanoes, therefore are composed of layers of lava and pyroclastic material. Some are more of one or the other, and some are about even.

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What is a hot-spot?

According to wikipedia.com In geology, a hotspot is a location on the Earth's surface that has experienced active volcanism for a long period of time. Most of the earth's "hot-spots" are found in the pacific region.

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What are the different types of Volcanoes?

There are mainly three types of volcanoe: Sheild, Strato and Cinder cone.

1. A Shield Volcanoes is basically a large volcano with shallow-sloping sides. Shield volcanoes are formed by lava flows of low viscosity, or lava that flows easily. This lava gives the volcano it's "shield shape". (when the volcano erupts, the low flow, after many years shapes the volcano)

2. Strato Volcanoe- is a tall, conical volcano composed of many layers of hardened lava, tephra, and volcanic ash. Stratovolcanoes are formed by viscous lava flows. Since the lava cools and hardens before spreading very far it gives the stratovolcano its interesting shape.

3. Cinder Cone is basically a steep conical hill of volcanic fragments that accumulate around and downwind from a volcanic vent. These volcano's contain gas bubbles "frozen" into place because the magma exploded into the air and then cooled quickly.[