9th Grade Chapter 8 Lesson 3

9th Grade Chapter 8 Lesson 3

• 1.
  9 th Grade Chapter 8 Lesson 3 Pgs. 213-223 For student Use Only
• 2.
  Volcanoes Volcano: Mostviolent naturally occuring disaster God also can control the volcano Volcano Structure: Volcano- opening in earth’s surface where gases, ash, and molten rock are ejected
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  Volcanoes Volcano: Partsof the Volcano: Vent: central channel Magma: magma is molten rock lies below the surface Cone: dust, ash, and magma can make a conical-shaped mountain Crater: bowl-shaped depression that surrounds the vent
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  Volcanoes Types ofVolcanoes: Cinder-Cone: composed of volcanic ash and rock fragments (cinders) Shield: Larger, flatter volcanoes made from runny lava Composite: Composed of layers of cinders and lava
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  Volcanoes Volcanic Activity:Active: Erupted in last 50 years Dormant: has not erupted in many years Extinct: A volcano that will PROBABLY not erupt again
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  Volcanoes Volcano Location:Three main belts (like three main earthquake belts: 1. Ring of Fire- 25% of Earth’s 850 Active volcanoes are there 2. Mediterranean Trans-Asiatic- (Europe to Asia) 3. Mid-Ocean Ridges- mid-ocean ALSO- Some volcanoes are in West Indies and African Rift Valley
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  Volcanoes Volcano Eruptions:Violent eruptions- more powerful than an atomic bombs Signs of Eruptions: 1. Swelling, Bulging in part of volcano (due to magma and gasses) 2. Minor Earthquakes begin 3. Explosion of Gas, Dust, and Steam
• 8.
  Volcanoes Volcano Eruptions:Huge rock pieces get thrown into the air Lava can erupt violently or dribble out Depends on Viscosity: viscosity (how it flows) Amount of gas in magma Sometimes (like Nevado De Ruiz) huge mud flows can accompany eruption
• 9.
  Volcanoes Solid Ejecta:Pyroclasts: solid particles or blocks of rock Volcanic Ash: pyroclast that is less than 4 mm Cinders: pyroclast that is less than 32mm but more than 4mm Volcanic blocks: solid, irregular lumps of lava Volcanic bombs: lava that is thrown high in the air
• 10.
  Volcanoes Volcanic Ejecta:Fiery Blasts: Lava is not usually very fast Super heated gas and Incandescent ash are very dangerous Superheated gas can blow as fast as the wind Nuee Ardente: heated gas and volcanic ash act as an avalanche (glowing avalanche) (Mt. Pelee)
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  Volcanoes Volcanic Structures:Calderas- sunk in hole- bowl shaped surface of crater Tunnels- lava hardens on top and then continues to flow under the surface
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  Volcanoes Volcanic Intrusions:Igneous Intrusion: Magma rock forces up surface of earth Dike: Vertical sheet of magma that hardens in a vertical fissure Sill: horizontal sheet of magma Laccolith: magma rock pushes surrounding surface up Batholith: large magma rock deposit