Volcanoes

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A volcano erupts when the pressure of a subterranean pool of magma becomes great enough to crack the earth's crust. Whether the eruption results in a violent explosion or a slow seepage depends on several different factors, according to How Stuff Works.

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  • What is the top of a volcano called?

    Q: What is the top of a volcano called?

    A: The top of a volcano is called the crater. A volcano is shaped like an inverted cone, and the tip of the cone is the crater. The crater is the opening of the vent in a volcano through which the molten magma or the lava is ejected.
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  • What is a main vent in a volcano?

    Q: What is a main vent in a volcano?

    A: The main vent of a volcano is the outlet chamber in the Earth's crust that allows hot magma to reach the surface. While secondary vents may form to alleviate the pressure caused by a magma chamber, the main vent is responsible for giving volcanoes their familiar cone shape.
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  • How do volcanoes affect the environment?

    Q: How do volcanoes affect the environment?

    A: An erupting volcano emits gases and dust particles that can cause profound changes in weather and climate throughout the world. Volcanism also affects the environment by producing acid rain and making ocean water warmer.
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  • What is a mudflow on a volcano called?

    Q: What is a mudflow on a volcano called?

    A: Mudflow on a volcano is called lahar and is typically caused by heavy rains during or after volcanic eruptions. Lahars can also occur when nearby ice or snow melts, carrying ash and rock debris down a volcano's slopes.
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  • Are volcanoes mountains?

    Q: Are volcanoes mountains?

    A: While many volcanoes are mountains, it is possible for a volcano to erupt from a vent in any type of land form. Over time, volcanoes become mountains by depositing their discharge around them in ever-increasing layers. Not all mountains are volcanoes.
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  • What damage do volcanoes cause?

    Q: What damage do volcanoes cause?

    A: Volcanoes cause physical damage to structures and buildings, wildlife, local vegetation and the atmosphere, as well as posing health risks. Residences within the vicinity of a volcanic eruption often receive timely notice before an eruption occurs. This reduces the likelihood of danger to humans.
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  • How many super volcanoes are there in the world?

    Q: How many super volcanoes are there in the world?

    A: The Earth has approximately 20 known supervolcanoes, according to James Morgan, who write for the BBC News. What constitutes a "supervolcano" is not clearly defined, so the term is avoided in the literature, but it is often used in reference to two distinct phenomena.
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  • What is an active volcano?

    Q: What is an active volcano?

    A: An active volcano is one that has had at least one eruption in the past 10,000 years. An active volcano can be dormant or erupting.
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  • How was Mount Kilimanjaro formed?

    Q: How was Mount Kilimanjaro formed?

    A: Mount Kilimanjaro is a stratovolcano that formed as the plates below it dropped and porous basalt rock magma erupted through the surface of the ocean. The magma and other debris formed layers with each eruption, eventually rising high enough to bring Mount Kilimanjaro to its height of 19,341 feet.
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  • How often does Old Faithful erupt?

    Q: How often does Old Faithful erupt?

    A: Old Faithful erupts at varying intervals from 60 to 110 minutes in length. The Yellowstone National Park staff offers predictions based on past activity; this is so that visitors can plan a visit to the geyser area during an eruption, which lasts between one-and-a-half minutes and five minutes.
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  • What country has the most volcanoes?

    Q: What country has the most volcanoes?

    A: Indonesia has the most volcanoes, with 76 volcanoes that have erupted within historical times. The Smithsonian Institution has 141 Indonesian entries in its volcano database; this includes volcanoes which have yet to erupt.
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  • What are active and inactive volcanoes?

    Q: What are active and inactive volcanoes?

    A: Active volcanoes are those that have erupted recently or regularly erupt, and inactive volcanoes are those that have not erupted for a long time. The exact time distinction between active and inactive volcanoes differs between experts.
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  • What are the main features of a volcano?

    Q: What are the main features of a volcano?

    A: The main features of a volcano include a vent, a summit crater and a magma chamber. The vent is an opening through which volcanic material is erupted. Volcanoes can have more than one vent. The summit crater is the large concave opening that holds the central vent at the top of the volcano. The magma chamber is the large pool-like structure inside the volcano that holds the magma.
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  • When did Mount Saint Helens erupt?

    Q: When did Mount Saint Helens erupt?

    A: Mount St. Helens' most significant eruption in modern times occurred on March 20, 1980. It was followed by additional eruptions between Dec. 7, 1989 to Jan. 6, 1990, Nov. 5, 1990 to Feb. 14, 1991, Oct.11, 2004, Mar. 8, 2005, and between Jan. 16, 2008 to July 10, 2008.
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  • What are the different parts of a volcano?

    Q: What are the different parts of a volcano?

    A: The main parts of a volcano include the summit crater, the magma chamber, the central vent and the edifice. While volcanoes vary considerably in terms of size and shape, most land volcanoes have structural similarities.
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  • What causes a volcano to erupt?

    Q: What causes a volcano to erupt?

    A: A volcano erupts when the pressure of a subterranean pool of magma becomes great enough to crack the earth's crust. Whether the eruption results in a violent explosion or a slow seepage depends on several different factors, according to How Stuff Works.
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  • What is an extinct volcano?

    Q: What is an extinct volcano?

    A: An extinct volcano is one that has not erupted in at least 10,000 years and is not expected to erupt in the future, according to Oregon State University. There can be confusion between dormant and extinct volcanoes, but the difference between the two is that a dormant volcano may erupt even if it is in the distant future.
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  • What is the closest volcano to Denver, Colorado?

    Q: What is the closest volcano to Denver, Colorado?

    A: There are no active volcanoes near Denver, Colorado. Nearby extinct volcanoes are located 2 hours from Denver in the Central Colorado volcanic field. These include the Grizzly Peak and Mount Aetna cauldrons and Bonanza and Marshall Creek calderas. The Central Colorado Volcanic Field is located in Park and Teller counties.
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  • What is a composite cone volcano?

    Q: What is a composite cone volcano?

    A: A composite cone volcano, or a stratovolcano, is built by multiple eruptions from surrounding volcanoes. They are formed over hundreds of thousands of years and have their entire structure build by magma flowing from geographically close volcanoes.
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  • What is the difference between magma and lava?

    Q: What is the difference between magma and lava?

    A: Magma and lava are the same substance in two different forms. Magma is molten rock that is found beneath the earth's crust, while lava is what magma becomes once it reaches the surface and erupts from a volcano or crack in the earth.
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  • What country has the most active volcanoes?

    Q: What country has the most active volcanoes?

    A: Indonesia has 147 volcanoes, 76 of which are still active making it the world's most active volcano country. The country consists of a chain of more than 13,000 islands that are spread out over an area similar in size to the continental United States.
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