TYPES OF VOLCANOES

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TYPES OF VOLCANOES
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TYPES OF VOLCANOES

• SHIELD VOLCANO
• Broad at the base
• Gentle Slopes
• Form from quiet eruptions
• Mafic lava
• Example Hawaiian Islands

Mauna Loa, Hawaii
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TYPES OF VOLCANOES

• CINDER CONE VOLCANO
• Steep slopes (close to 40 degrees)
• Not more than a few hundred meters high
• Explosive eruptions
• Pyroclastic materials form

Amboy Crater, California
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TYPES OF VOLCANOES

• COMPOSITE VOLCANO
• Also known as STRATOVOCANO
• Made of alternating layers of lava and
  pyroclastic material
• Made from quiet AND explosive eruptions
• Form large, steep-sided mountains

St. Augustine, Alaska
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CALDERAS

• A depression at the top of a volcano
• Form after the magma chamber below empties
• Top of volcano collapses inward on itself
• Lakes will form in the depression

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Predicting Volcanic Eruptions

• Earthquakes
• Bulges in the ground
• Changes in the amount or type of gas that is
  released in the area

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Intrusive Activity

• When magma slowly comes to the surface, we say it
  is an INTRUSION
• If the magma solidifies in the ground it can form
  large formations of igneous rock called PLUTONS