1. Earthquakes

3. Earthquake Vibration due to the rapid release of energy
Caused by slippage along a break in earth’s crust

4. Faults Fault: fracture (break) in Earth where movement has occurred
Fractures form when
stress on rocks exceeds
their strength
Three types of stress:
Tension
Compression
shearing

5. Fault types Reverse: caused by compression Normal: caused by tension
Strike-slip: caused
by shearing

6. Location of the earthquake
Focus: the point under the surface where the earthquake starts
Epicenter: the point of the surface directly above the focus

7. Earthquake waves
Seismic waves: the vibrations of the ground during an earthquake
Primary waves
Push and pull rock in the same direction the wave is moving
Like a slinky
Fastest wave
wave simulation

8. Cause rock to move at right angles to the direction of wave movement
Secondary waves
Cause rock to move at right angles to the direction of wave movement
Surface waves
Travel along earth’s outer surface
Move in two directions as they pass through rock
Wave animation

9. Measuring earthquakes
Richter scale: measures wave amplitude; based on size of largest wave
Moment magnitude: measure using average displacement along the fault, surface area of the fault, and strength of the rock involved
intensity; greatest near the epicenter

10. Earthquake hazards and research
Earthquake destruction
Anatomy of an earthquake (Learn360)
Swaying
Top ten
tsunami

11. Liquefaction
When fluid saturated soil liquifies due to seismic vibrations
Bobbing Building
Liquefaction video
More liquefaction - shifting sidewalk

12. Landslide
Christchurch earthquake

13. Tsunamis and fires Tsunami Formation of a tsunami Tidal Bore
Tidal bore Amazon

14. Pancaking