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 Pacific Ring of Fire?

    Q: What is the Pacific Ring of Fire?

    A: The Pacific Ring of Fire is the name for a horseshoe-shaped region of high seismic and volcanic activity surrounding the Pacific Ocean Basin. In addition to volcanoes, the area encompasses major fault zones. It spans 25,000 miles and touches a number of island chains, as well as four continents.
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  • Where is Mount Kilimanjaro located?

    Q: Where is Mount Kilimanjaro located?

    A: Mount Kilimanjaro is located in Tanzania. It is a dormant volcano comprising three volcanic cones, and is the highest peak in Africa.
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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 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 gases are produced by volcanic eruptions?

    Q: What gases are produced by volcanic eruptions?

    A: Volcanic eruptions mainly produce steam (H2 0 ), sulfur dioxide (SO 2 ) and carbon dioxide (CO 2 ). They do release other gases in lesser amounts, such as carbon monoxide (CO), helium (He), hydrogen (H 2 ), hydrogen chloride (HCL), hydrogen fluoride (HF) and hydrogen sulfide (H 2 S).
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  • What are the positive and negative effects of volcanoes?

    Q: What are the positive and negative effects of volcanoes?

    A: The negative effects of volcanoes include the destruction of man-made and natural environments and the death of human, animal and plant life. On the other hand, volcanoes generate geothermal energy and produce nutrients that result in fertile soil.
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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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  • How does a volcano form?

    Q: How does a volcano form?

    A: A volcano forms when a vent in the Earth's crust allows magma to well up from below. The magma fills a void underneath the surface, and when it builds up enough pressure, it bursts through to the surface. As the magma cools, it hardens into rock, and multiple eruptions may build up the mountainous form of a volcano.
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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 do volcanologists do?

    Q: What do volcanologists do?

    A: Volcanologists study the processes of volcano formation and their eruptive activity. In addition to studying current volcanic activity, they also study the eruptions of volcanoes throughout history.
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  • Why are there volcanoes?

    Q: Why are there volcanoes?

    A: Volcanic vents allow the Earth to release built up gases from the heat and pressure emanating from its core. Magma rises towards the surface, and as the pressure builds the magma seeks outlets through which to flow. The higher the pressure build-up, the greater the volcanic explosion.
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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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  • 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 change the Earth's surface?

    Q: How do volcanoes change the Earth's surface?

    A: Volcanic eruptions involve the incursion of liquid magma into a physical environment, and the effects include major transformations, ranging from the formation of new land to the destruction of the viability of an existing environment. Just one example of the creation of new land comes from the Hawaiian Islands, which appeared as magma cooled into land after eruptions.
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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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  • 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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  • 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 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 happened when Mount Etna erupted?

    Q: What happened when Mount Etna erupted?

    A: Noxious fumes and tremendous amounts of ash and molten lava spewed from Mount Etna in 1669 and killed more than 20,000 Sicilians. Just prior to this eruption, an associated earthquake killed an additional 15,000 people.
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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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