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 A volcano is an opening in the Earth’s crust where lava comes out.

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Presentation on theme: " A volcano is an opening in the Earth’s crust where lava comes out."— Presentation transcript:

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2  A volcano is an opening in the Earth’s crust where lava comes out

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4  Volcanoes can be found in 3 general locations 1. Divergent Boundaries 2. Subduction boundaries 3. Hot Spots

5  At divergent boundaries, volcanoes are created as the plates slide apart. Iceland is a good example.

6  When one plate subducts under another, a volcano is created. A good example is Mt. Fuji in Japan, Mt. St Helens in Washington and Aleutian islands in Alaska

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8  Hot Spots are volcanoes that form in the middle of a tectonic plate. Hawaii is an example. As the plate moves, the hot spot stays in the same place, so a chain of islands is often created.

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10  There are 3 kinds of volcanoes 1. Shield Cone 2. Cinder Cone 3. Composite Cone

11  Shield Cone volcanoes are not very tall and formed by layers of lava.  Quiet Eruptions

12  Steep Volcano with explosive eruptions.  Explosive eruptions caused by gas.  Formed by layers of volcanic rock

13  Made of alternating layers of lava and rock  Alternates in explosive eruption and quiet eruptions  AKA Stratocones

14  Mafic lava – dark, no gas, not explosive, thin  Felsic lava – light, lots of gas, explosive, thick  Pahoehoe – ropey cooled lava, usually from mafic lava  Aa – thick, blocky cooled lava from felsic lava

15 pahoehoe aa

16  Vent – name of actual opening of volcano  Crater – surrounding area around vent.  Caldera – a collapsed vent; after a volcano explodes, a huge opening left over from explosion.

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