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53 Cards in this Set
- Front
- Back
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Volcano
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a weak spot in the crust where molten material, or magma, comes to the surface.
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magma
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a molten mixture of rock-forming substances, gases, and water from the mantle.
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lava
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magma that reaches the surface
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Where are most of earths volcanoes found?
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Along plate boundaries.
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How do hot spot volcanoes form.
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A volcano forms above a hotspot when magma erupts through the crust and reaches the surface
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how many active volcanoes are on land?
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600 active volcanoes but many are in the sea.
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What is the most major belt?
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Ring of Fire
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Ring of Fire
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a major volcanic belt formed by the many volcanoes that rim the Pacific Ocean
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Where do belts form?
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on the plate boundaries
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What type of boundary is formed where volcanoes form?
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divergent boundary.
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Island arc
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a string of islands that is made by volcanoes
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Hot spot
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an area where material from deep within the mantle rises and then melts, forming magma.
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Why is it helpful to know the physical and chemical properties of a substance?
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Each substance has a particular set of physical and chemical properties. These properties can be used to identify a substance or to predict how it will behave.
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What causes some liquids to flow more easily thann others?
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Because liquids differ in viscosity, some liquids flow more easily than others.
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What factors determine the viscosity of magma?
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The viscosity of magma depends upon silica content and temperature.
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elements
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a substance that cannot be broken own into other substances
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compounds
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a substance made of two or more elements that have been chemically combined.
Ex. Water, carbon dioxide, and table salt. |
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physical property
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any characteristic of a substance that can be observed or measured without changing the composition of the substance.
Ex: density, harness, melting point, boiling point and wether a substance is magnetic |
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chemical property
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any property that produces a change in the composition of matter.
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viscosity
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the resistance of a liquid to flowing.
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silica
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made up of particles of the elements oxygen and silicon
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Pahoehoe
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fast moving, hot lava that has low viscosity.
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How hot is lava and magma?
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temperature can range between 750*C to 1,175*C
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aa
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lava that is cooler and slower-moving.
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What happens when a volcano erupts?
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a. When a volcano erupts, the force of the expanding gases pushes magma from the magma chamber through the pipe until it flows or explodes out of the vent
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What are the two types of volcanic eruptions?
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Geologist classify volcanic eruptions as quiet or explosive.
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What are a volcano's stages of activity?
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either active, dormant, or extinct.
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Magma Chamber
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A pocket that collects magma beneath the volcano.
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Pipe
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a long tube in the ground that connects the magma chamber to Earth’s Surface.
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Vent
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Where Molten rock and gas leave the volcano.
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Lava Flow
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The area covered by lava as it pours out of a vent.
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Crater
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a bowl-shaped area that may form at the top of a volcano around the central vent.
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Quite Eruptions
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-Magma is low in Silica (Low Viscosity)
-Produces both Pahoehoe and aa |
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Explosive Eruptions
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-High in silica (high viscosity)
- The gases get stuk in the pipe and pressure builds up and it explodes. |
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pyroclastic flow
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when an explosive eruption hurls out a mixture of hot gases, ash, cinders, and bombs
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Dormant
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will awkaen in the future and become active in the future.
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Active
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able to erupt whenever
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Extinct
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dead and unlikely to erupt again
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What landforms do lava and ash create?
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SHield Volcanos, CInder Cone Volcano's, Composite Volcano's, and Lava Plateaus
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How does magma that hardens beneath the surface create landforms?
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volcanic necks, dikes, and sills, batholis, and dome mountains.
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What other distinctive features occur in volcanic areas?
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hot springs and geysers are types of geothermal activity.
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Shield Volcano
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Such lava flows gradually bild a wide, gently sloping mountain
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Cinder Cone
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a steep cone shaped Volcano that has vents.
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Composite Volcanoes
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tall, cone shaped mountains in which layers of lava alternate with layers of ash.
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Lava Plateaus
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a plateau volcano where lava is pored over land.
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Caldera
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the huge whole left by the collapse of a volcanic mountain.
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Why do people settle next to a volcano?
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to get fertile soil
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Volcanic neck
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a big mountain that is fromed when magma gets stuck in the pipe.
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Dike
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when magma that forces itself across rock layers hardens
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Sill
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when magma squeezes between horizontal layers of rock
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Batholith
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a mass of rock formed when a large body of magma cools inside the crust.
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Geothermal Activity
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magma a few kilometers beneath Earth's surface heats under ground water.
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Geyser
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when hot water is sprayed into the air really fast.
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