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17 Cards in this Set
- Front
- Back
volcano
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-a mountain that builds up around an opening in Earth's crust
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volcanic eruption
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-when melted rock, gases, and pieces of rock are formed out of a volcano
-can cause land to change suddenly |
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magma
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-melted rock
-when trapped gases build up pressure in magma there can be an explosive eruption (like Mount St. Helens, May 1980) |
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vent (in a volcano)
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-a central opening in a volcano
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lava
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-what magma is called once it reaches Earth's surface
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volcanic mountain
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-forms when ash and lava build up around the vent
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Where do volcanoes form?
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-most occur along fault lines
-also form where Earth's plates move apart -they form along the edges of spreading plates |
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rift volcanoes
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-volcanoes that form along the edges of spreading plates
-most rift volcanoes form along the ocean floor |
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hot spots
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-a place where magma partially melts Earth's crust
-as a plate moves over a hot spot, magma forms, forming a volcano -an example in the Hawaiian Islands |
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active volcano
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-the volcano is still erupting
-example is the Island of Hawaii |
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dormant volcano
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-plate passed over the hot spot a long time ago and the volcano no longer erupts
-example is the Island of Kauai |
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Kinds of volcanoes
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-Cinder-cones, shields, composites
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crater
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-a cup-like shape forming around the vent of a volcano
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Cinder-Cone Volcano
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-shaped like a cone
-has steep sides -consists of rock fragment layers -thick magma -a lot of gas is trapped in magma -because magma is thick, it can become clogged in the volcano -cuplike shape formed around the vent is the crater |
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Shield Volcano
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-wide, flat sides
-formed by layers of lava that build up over time and flows gently in all directions -Mauna Loa, a shield volcano, is world's largest volcano |
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Composite Volcano
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-made up of layers of lava and ash
-forms during periods of quiet eruptions and explosive eruptions -over time, layers build up to form a cone shape -usually symmetrical - the shape on one side of the cone matches the shape on the other side |
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How can you protect yourself during an erupting volcano?
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-be prepared
-stay away from active volcano sites and flowing lava -have a pair of goggles and breathing mask available for each member of the family in your safety kit -if your town has a warning, follow all directions -if you are inside during an eruption, close all windows and doors. Ensure pets are inside -if you are caught outdoors, find the nearest shelter and stay inside |