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VOLCANOES
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Volcano In Hawaii Kilauea Volcano Erupts
This Volcano has been continuous erupting since 1982
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What is A Volcano? ~An opening in the earth's crust through which molten lava, ash, and gases are ejected.
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The 3 main types Of Volcanoes
~ Shield Volcano ~ Cinder Cone Volcano ~ Composite Volcano
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Shield Volcano These are large, broad volcanoes that look like shields from above. The lava that pours out of shield volcanoes is thin, so it can travel for great distances down the shallow slopes of the volcano. These volcanoes build up slowly over time, with hundreds of eruptions, creating many layers. They’re not likely to explode catastrophically. (Hawaii)
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Cinder Cone Volcano These are the simplest type of volcano. They occur when particles and blobs of lava are ejected from a volcanic vent. The lava is blown violently into the air, and the pieces rain down around the vent. Over time, this builds up a circular or oval-shaped cone, with a bowl-shaped crater at the top. Cinder cone volcanoes rarely grow larger than about 1,000 feet above their surroundings.
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Composite Volcano Composite volcanoes, or stratovolcanoes make up some of the world’s most memorable mountains.These volcanoes have a conduit system inside them that channels magma from deep within the Earth to the surface. They can have clusters of vents, with lava breaking through walls, or issuing from fissures on the sides of the mountain. With all this material coming out, they can grow thousands of meters tall. As we’ve seen with the famous Mount Saint Helens, composite volcanoes can explode violently.
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Where are volcanoes likely to occur?
Volcanoes occur in weak spots in the earth’s crust There are many volcanoes along the Pacific Ocean. Many islands in the Pacific Ocean are actually volcanoes. They form a ring around the ocean which is called the “Pacific Ring of Fire.” Although there are some other “rings of fire”, the “Pacific Ring of Fire” is the biggest. There are approximately five hundred active volcanoes, that are known, lying in these rings.
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Volcanoes In Other Places
Mariner 9 imagery of Olympus Mons volcano on Mars Volcanoes aren’t just a thing from earth they also happen on other planets as seen in this picture. But while on other planets there is no destruction as we have seen from volcanoes on earth.
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When and how do eruptions occur?
Steam and gases from magma in the earth create bubbles that expand and burst when the pressure above them is lessened. These bubbles usually burst with a tremendous force that along with escaping gas comes magma too. In some cases, it takes years for the magma to break through the surface of the earth.
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Why do eruptions occur? Eruptions occur when underground pressure is
released when blocks of the earth’s crust shift. For example, earthquakes.
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