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Questions and Answers
What is the name of the moon of Saturn that has methane-spewing cryovolcanoes?
What is the name of the moon of Saturn that has methane-spewing cryovolcanoes?
What is the name of the volcano that has experienced one or more eruptions that produced over 1,000 cubic kilometers of volcanic deposits in a single explosive event?
What is the name of the volcano that has experienced one or more eruptions that produced over 1,000 cubic kilometers of volcanic deposits in a single explosive event?
What is the name given to the solid material that is expelled in a volcanic eruption?
What is the name given to the solid material that is expelled in a volcanic eruption?
What is the name of the volcanic island in the Aeolian Islands of Italy that gave rise to the name 'volcano'?
What is the name of the volcanic island in the Aeolian Islands of Italy that gave rise to the name 'volcano'?
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What is the name of the moon of Jupiter that has a system of water cryovolcanoes?
What is the name of the moon of Jupiter that has a system of water cryovolcanoes?
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What is the name given to the explosive volcanic activity that forms pyroclastic deposits?
What is the name given to the explosive volcanic activity that forms pyroclastic deposits?
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What is the name given to the classification system used to express the intensity of explosive volcanism?
What is the name given to the classification system used to express the intensity of explosive volcanism?
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What is the name of the moon of Neptune that has ice cryovolcanoes?
What is the name of the moon of Neptune that has ice cryovolcanoes?
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What is the name given to the type of lava that is characterized by smooth and often ropey or wrinkly surface textures?
What is the name given to the type of lava that is characterized by smooth and often ropey or wrinkly surface textures?
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Study Notes
Volcanoes: A Summary
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A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
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Volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater.
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Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool the Earth's troposphere.
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Other planets besides Earth have volcanoes. For example, Mercury has pyroclastic deposits formed by explosive volcanic activity.
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The word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology.
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Earth's lithosphere, its rigid outer shell, is broken into sixteen larger and several smaller plates. Most volcanic activity on Earth takes place along plate boundaries.
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Volcanic fissure vents are flat, linear fractures through which lava emerges.
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Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent.
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Stratovolcanoes (composite volcanoes) are tall conical mountains composed of lava flows and tephra in alternate layers, the strata that gives rise to the name.
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A supervolcano is a volcano that has experienced one or more eruptions that produced over 1,000 cubic kilometers (240 cu mi) of volcanic deposits in a single explosive event.
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Submarine volcanoes are common features of the ocean floor.
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Subglacial volcanoes develop underneath icecaps.
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The material that is expelled in a volcanic eruption can be classified into three types: volcanic gases, lava flows, and tephra (solid material).Overview of Volcanoes and Their Characteristics
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The viscosity and amount of dissolved gas in magma are largely determined by the amount of silica in the magma.
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Lava can be broadly classified into four different compositions: mafic, felsic, intermediate, and ultramafic.
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Mafic lava flows are characterized by two surface textures: ʻaʻa and pāhoehoe. ʻAʻa is rough and clinkery, while pāhoehoe is smooth and often ropey or wrinkly.
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Tephra is made when magma inside the volcano is blown apart by the rapid expansion of hot volcanic gases. Solid particles smaller than 2 mm in diameter are called volcanic ash.
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Eruption styles are broadly divided into magmatic, phreatomagmatic, and phreatic eruptions. The Volcanic Explosivity Index (VEI) is used to express the intensity of explosive volcanism.
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As of December 2022, the Smithsonian Institution's Global Volcanism Program database lists 9,901 confirmed eruptions from 859 volcanoes in the Holocene Epoch (the last 11,700 years).
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Volcanoes are informally described as erupting, active, dormant, or extinct. The definitions of these terms are not entirely uniform amongst volcanologists.
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The three common popular classifications of volcanoes can be subjective and some volcanoes thought to have been extinct have erupted again.
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Hazards associated with volcanic eruptions include phreatic eruptions, explosive eruption of high-silica lava, effusive eruption of low-silica lava, sector collapses, pyroclastic flows, lahars, and carbon dioxide emission.
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Volcanic eruptions may have contributed to major extinction events, such as the End-Ordovician, Permian-Triassic, and Late Devonian mass extinctions.
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Tuff formed from volcanic ash is a relatively soft rock and has been used for construction since ancient times.
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Volcanic ash and weathered basalt produce some of the most fertile soil in the world, rich in nutrients such as iron, magnesium, potassium, calcium, and phosphorus. Volcanic activity is also responsible for emplacing valuable mineral resources, such as metal ores.
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Many volcanoes near human settlements are heavily monitored with the aim of providing adequate advance warnings of imminent eruptions to nearby populations.Volcanism - from cryovolcanoes to exoplanets
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Io, one of Jupiter's moons, is the most volcanically active object in the Solar System, with over 400 active volcanoes.
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Europa, another of Jupiter's moons, has a system of water cryovolcanoes.
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Triton, a moon of Neptune, has ice cryovolcanoes.
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Enceladus, a moon of Saturn, has cryovolcanoes that emit water, liquid nitrogen, ammonia, dust, or methane compounds.
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Titan, another moon of Saturn, has methane-spewing cryovolcanoes that are a significant source of methane in its atmosphere.
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Cryovolcanism may also be present on the Kuiper Belt Object Quaoar.
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A 2010 study suggests that exoplanet COROT-7b could have intense volcanic activity caused by tidal heating from its host star.
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Ancient accounts ascribed volcanic eruptions to supernatural causes, such as the actions of gods or demigods.
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Early ideas about volcanoes proposed that they were ducts for the Earth's tears or were caused by burning sulfur, bitumen, and coal.
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Before the modern understanding of the Earth's mantle structure, various explanations were proposed for volcano behavior, such as chemical reactions and a thin layer of molten rock near the surface.
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Description
Test your knowledge of volcanoes with this informative quiz! Learn about the different types of volcanoes, their characteristics, eruption styles, and hazards associated with volcanic activity. From the most volcanically active object in the Solar System to the fertile soil produced by volcanic ash, explore the fascinating world of volcanism. Whether you're a science buff or just curious about the Earth's fiery phenomena, this quiz is sure to challenge and educate you.
