Volcanoes erupt because of the density of the material inside them. The liquid in the Earth is called magma. The core of the Earth, where magma is made, can reach up to 9000 degrees Fahrenheit. When magma comes out, it is called lava. The amount of time and the number of times that avolcano erupts is also up to density of the Earth. The density of the rock always puts pressure on the Earth and magma so that it could erupt for a very long time. The eruption can have as much as 100 tons of pressure.
Volcanoes sometimes erupt to let the Earth cool off. It also allows the earth to release a lot of pressure and heat that has been building up because of the magma that is in volcanoes. The Earth is made up of many large plates and when the plates collide it can become an eruption. The plates move very slowly but even small movements can cause a volcano to erupt. Seven of the plates are extremely big and when they move, they can cause volcanoes worldwide.
Volcanoes are located where tectonic plates meet. The Ring of Fire an area next to the Pacific Ocean where over 75% of the volcanoes on Earth are found. Some signs of volcano eruptions are earthquakes. Volcanoes might bring some changes. Sometimes animals behave very strangely. Most of the volcanic eruptions in the world are very quiet and not big explosions. In Hawaii, most of the volcanoes have very mild explosions. The most dan gerous type of volcano happens when the magma is very gooey. When that happens it acts like glue and plugs up the top of the volcano causing a lot of pressure.
There are three different stages of a volcano. These stages are dormant, active and extinct. Dormant means that a volcano has erupted for a very long time but could possibly erupt in the future. An active volcano is one that has erupted within the last 500 years while an extinct volcano is one that will never erupt again. There are over 1500 active volcanoes on Earth. In America, many volcanoes are found in Oregon, Hawaii, California, and also Washington. There are also three types of volcanoes, including cinder cones, composite volcanos, and shield volcanoes. Cinder cones are made of small fragments of lava. Composite volcanos are made of volcanic rocks. The last type of volcano is the shield volcano. It is shaped like a shield. It has a great amount of power inside. Throughout history, volcanoes have killed thousands of people. That is how powerful a volcanic eruption can be.
More and more people are moving to very dangerous places. They are dangerous because they are next to volcanoes that are in the Earth. The volcanoes there can easily hurt people. There is something good though. Most volcanoes have become dormant. And some of the most dangerous volcanoes from the past are about to be extinct or are extinct or they are dormant so people can live there without always having to worry about when a volcano could erupt. Scientists do not know exactly when a volcano will erupt but they can keep track of how active a volcano is and the earthquakes around the volcano can help predict an eruption.
Here is what you can do so that you could stay safe in case a volcano eruption happens. If you live close to one, you should be careful. Keep a kit where you live in case of an emergency. You should keep a flashlight and battery in your kit as well as a battery operated radio, emergency food and water and dust masks, goggles and hard hats. To know when a volcano is coming listen to the radio or a weather forecast on a TV. Most of the time when a tornado erupts you have to evacuate. This is what you need these things for. If a volcano is erupting wear goggles to protect your eyes. Use a dust cover to cover your nose and mouth so that you don’t breathe volcanic ashes. Wear a long sleeves shirt and very long pants to help protect your skin so that you won’t get hurt. In a typical "oceanic" environment, volcanoes are aligned along the crest of a broad ridge that marks an active fracture system in the oceanic crust. Basaltic magma, generated in the upper mantle beneath the ridge, rise along fractures through the basaltic layer. Because the granitic crustal layer is absent, the magma are not appreciably modified or changed in composition and they erupt on the surface to form basaltic volcanoes.[1]
References
[11 Facts About Volcanoes.” DoSomething.org. N.p., n.d. Web. 22 Sept. 2014.] [“Experts You Should Follow.” Answers. Answers Corporation, n.d. Web. 22 Sept. 2014.] [Mara, Wil. Why Do Volcanoes Erupt? Tarrytown, NY: Marshall Cavendish Benchmark, 2010. Print.] [Person, Stephen. Devastated by a Volcano! New York: Bearport Pub., 2010. Print.] [Silverstein, Alvin, Virginia B. Silverstein, and Laura Silverstein. Nunn. Volcanoes: The Science behind Fiery Eruptions. Berkeley Heights, NJ: Enslow, 2010. Print.] [“Volcano World.” Why Are There Volcanoes? Why Do They Erupt? N.p., n.d. Web. 22 Sept. 2014.] [“Volcanoes.” Annenberg Learner Interactives. N.p., n.d. Web. 22 Sept. 2014.] [“Weather Wiz Kids Weather Information for Kids.” Weather Wiz Kids Weather Information for Kids. N.p., n.d. Web. 22 Sept. 2014.]