Upcoming SlideShare
Loading in...5

Like this? Share it with your network

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads


Total Views
On Slideshare
From Embeds
Number of Embeds



Embeds 5 5

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

    No notes for slide


  • 1. Earthquakes
  • 2. Elastic Limit
    • The point of how far an object can bend.
      • Ex: Rubber band; Wooden Stick
    • Rocks have an elastic limit .
      • When pass their elastic limit, rocks break.
  • 3.  
  • 4. Faults
    • When rocks break, they move along surfaces called faults .
    • Rocks can move up, down, or sideways along a fault.
      • Normal, Reverse, Strike-slip faults.
    • Forces within Earth (CONVECTION) cause plates to move -> Puts stress on rocks.
  • 5. Earthquake Distribution-I Fig. 4-7
  • 6. How Earthquakes Occur
    • Rocks move past each other along faults (B/c of tectonic plate movement).
    • Rough surfaces of rock catch against each other.
    • Plates continue to move despite stuck rocks.
    • Rocks become stressed beyond their elastic limit , they break, move along the fault, and return to their original shape.
  • 7.
    • To relieve stress, rocks will bend, compress, or stretch.
    • If rocks break, the resulting vibration is an earthquake .
    • Locations of earthquakes outline the tectonic plates .
  • 8. Seismic Waves
    • Seismic waves are the energy released when rocks break along faults.
    • “ Focus” = the point at which this energy is first released.
    • Seismic waves are produced and travel outward from the earthquake focus .
  • 9.  
  • 10. Types of Seismic Waves
    • Primary Waves (P-waves)
      • Cause particles in rocks to move back & forth in same direction .
      •  Ex: Stretched Spring
    • Secondary Waves (S-waves)
    •  Cause particles in rocks to move at right angles to the direction of the wave travel .
    • Surface Waves
    •  Move rock particles in a backward, rolling, side-to-side, swaying motion .
    •  Most damaging type of seismic waves.
  • 11. Epicenter
    • Earthquake epicenter = the point on the Earth’s surface directly above the earthquake’s focus .
    • Speeds of seismic waves allows us to determine how far away earthquake epicenter is .
      • Measured with Seismograph .
  • 12. Measuring Earthquakes-I
  • 13. Measuring Earthquakes
    • Richter Scale
      • Used to measure the strength of an earthquake .
      • Based on the height of the lines on the seismograph.
      • Scale has no upper limit, but 9.5 is estimated maximum.
  • 14. Measuring Earthquakes
    • Mercalli intensity scale
      • Used to measure the intensity of an earthquake based on the amount of damage caused by the earthquake.
      • Scale has 12 levels.