Earthquakes

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Earthquakes
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Fault

• Break or fracture in lithosphere
• Shows evidence of moving
• Usually located along plate boundaries

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Normal fault

• Tectonic plates are moving apart
• Lithosphere is stretching

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Reverse fault or thrust fault

• Tectonic plates are moving towards one another
• Oreo demo

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Strike-Slip fault

• Tectonic plates slide past each other

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What causes an earthquake?

• The release of stored up energy as the plates
  move past each other
• The energy moves outward from the fault in all
  directions in the form of waves
• When the waves reach the earths surface this
  causes the ground to shake

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Primary waves

• Compression waves
• Push and pull
• Slinky demo
• The fastest seismic wave

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Secondary waves

• Shear waves
• Side to side motion
• Slinky demo
• Slower than primary waves
• Compare to thunder and lightning

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Love waves

• Surface waves
• Cause the most damage to buildings
• Travel the slowest of all seismic waves

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How far is the earthquake?

• Detect p-waves and s-waves on a seismograph
• Calculate difference between waves

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• Calculate distance to earthquake
• Distance rate X time
• Example
• You are traveling 30 miles/hour and you
  travel for 2 hours. What distance have you
  traveled?
• Distance (30 miles/hour)x(2 hours)
• 60 miles

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3 locations to determine where earthquake is
located
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How can structures be built to withstand
earthquakes?

• Structure demos
• Weight
• Height
• Shape

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Test how building react in earthquakes

• Decide on a design for your building
• Draw a picture
• Build structure out of spaghetti and clay
• Test structure on shake table