Our Dynamic Earth

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Our Dynamic Earth

• Chapter 5

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Lesson 1, Earths Landforms

• Landform- a physical feature on Earths surface.

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The Ocean Floor

• Abyssal Plain- wide, flat area of the ocean
  floor.
• Trenches- deepest parts of the ocean floor.
• Rift Valley- indentation along tops of underwater
  mountains.

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The Earths Layers

• Atmosphere- includes all the gases around Earth.
• Hydrosphere- all of Earths water.
• Crust- rocky layer of Earth.
• Mantle- Earths interior below the crust.
• Inner Core- deep inside Earth made of solid
  metals.

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The Earths Layers

• Diagrams

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Plate Tectonics

• Geologist- a scientist who examines rocks to find
  out about Earths history and structure.

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Theory of Continental Drift

• Theory that the continents slowly moved to the
  position where they are today.
• Rock types- are the same in Eastern South America
  and western Africa.

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How Do Mountains Form?

• Faults- deep cracks in the Earths crust.
  Movement along these cracks can form mountains.

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Mountains

• Folded mountains
• The Himalayan Mountains

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Mountains

• Fault-block Mountains
• The Sierra Nevada Mountains

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Volcanoes

• Volcano- an opening in Earths crust.
• Most likely to form at plate boundaries.

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Volcanoes

• Tend to erupt when one plate is pushed under
  another plate.
• Rocks in the mantle melt and magma forms in a
  chamber.
• Pressure in the chamber grows and the magma is
  forced upward through cracks.
• Magma reaching the Earths surface is called lava.

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Cinder Cone Volcanoes

• Form when thick lava is thrown into the air and
  falls as chunks or cinders.

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Volcanoes Building Islands

• Hot Spot- a stationary pool of magma below
  Earths crust. As the plate moves, new islands
  are formed.

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Earthquakes

• Earthquake- sudden movement of the Earths crust.
• Waves move like ripples on a pond, making the
  surface and anything on it move.

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Earthquakes

• Earthquakes happen along the boundaries of
  tectonic plates.

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How is an Earthquakes Energy Measured?

• Magnitude- a measure of the amount of energy
  released by an earthquake.
• Richter Scale- measures the magnitude at the
  epicenter.

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How is an Earthquakes Energy Measured?

• Mercalli Scale- measures what people felt and
  what happened to objects at a specific location.

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Tsunamis

• Tsunami- a huge wave, usually occurring after an
  underwater earthquake.

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Weathering

• Chemical weathering- acid rain can wear away at
  stone and metals.

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Weathering

• Erosion- weathered rock is moved from one place
  to another place.

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Depostion

• As water is running faster, it can wash away soil
  and rock.
• When the water slows, the water will drop the
  material in another place.