Download Earthquakes - Colorado School of Mines

Earthquakes
Fault
• Break or fracture in lithosphere
• Shows evidence of moving
• Usually located along plate boundaries
Normal fault
• Tectonic plates are moving apart
• Lithosphere is stretching
Reverse fault or thrust fault
• Tectonic plates are moving towards one
another
• Oreo demo
Strike-Slip fault
• Tectonic plates slide past each other
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 earth’s surface this
causes the ground to shake
Primary waves
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Compression waves
Push and pull
Slinky demo
The fastest seismic wave
Secondary waves
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Shear waves
Side to side motion
Slinky demo
Slower than primary waves
Compare to thunder and lightning
Love waves
• Surface waves
• Cause the most damage to buildings
• Travel the slowest of all seismic waves
How far is the earthquake?
• Detect p-waves and s-waves on a seismograph
• Calculate difference between waves
• 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
3 locations to determine where
earthquake is located
How can structures be built to
withstand earthquakes?
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Structure demos
Weight
Height
Shape
Test how building react in earthquakes
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Decide on a design for your building
Draw a picture
Build structure out of spaghetti and clay
Test structure on shake table