Physical and Ecological Processes

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Physical and Ecological Processes

• SOL WG.2b

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Plate Tectonics

• The surface of the earth is constantly changing
  due to plate tectonics and erosion and weathering.

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Volcanoes

• Earthquakes and volcanoes can occur anywhere on
  the surface of the earth, including underwater,
  but they are more common at plate boundaries.

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Volcanoes

• Sometimes volcanoes occur far from plate
  boundaries. These areas are called hot spots. A
  good example of a hot spot is the formation of
  the Hawaiian Islands in the middle of the Pacific.

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Volcanoes

• There is an area around the Pacific Ocean where
  many plates come together known as The Ring of
  Fire. This area has many active and dormant
  volcanoes and volcanic eruptions are frequent.

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Volcanoes

• Scientists cannot predict when volcanoes will
  erupt.
• People live near volcanoes because volcanic ash
  is extremely fertile and good for farming.

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Earthquakes

• Earthquakes are more common at plate boundaries.
• The center of an earthquake on the surface of the
  earth is called the epicenter.
• A seismograph is a device that detects if an
  earthquake has occurred.
• The Richter Scale is a scale used for measuring
  the intensity of an earthquake.

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Tsunami

• Tsunamis are giant waves caused by earthquakes or
  volcanic explosions.
• Tsunamis can be detected with an early warning
  system but not all countries have the money to
  install them.

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An early warning system in the Pacific Ocean.
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Tsunami

• See a tsunami here
• http//www.youtube.com/watch?vw9ygYqj4rVM

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Humans and Earthquakes

• Humans cant predict earthquakes but they can
  build better buildings that will withstand the
  effects of an earthquake.

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Erosion and Weathering

• The surface of the earth is also being formed by
  erosion and weathering.
• Weathering breaks rocks into smaller pieces.
• Erosion moves pieces of rock or dirt.

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Erosion

• After rocks have been broken into smaller pieces
  the debris is moved by erosion. The agents of
  erosion are

A. Wind
B. Water
C. Ice
D. Gravity
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Erosion

• Erosion has natural causes and human causes.
• People can take steps to prevent erosion by using
  nets, covering exposed earth with straw, and
  replanting vegetation.

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Floods

• Floods happen when there is too much rain and
  rivers overflow their banks.
• People can try to prevent floods by building
  embankments or levees.

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Floods

• Typically, areas that are low in elevation and
  near rivers or the mouth of rivers experience
  floods. A few areas that have floods are
• Along the Mississippi River in the U.S.
• Bangladesh
• Parts of Eastern China

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