1. Earthquakes
June 25, 2018

2. Earthquakes What is an Earthquake?
Rapid release of energy along a fracture in the Earth’s crust
Sudden movement releases energy
Rocks deform (bend)
Friction prevents movement

3. How are Earthquakes Measured?
Seismograph measures earthquake waves
Three types of Earthquake Waves (in order of arrival time)
Primary (P-waves)
Secondary (S-waves)
Surface

4. How is an Earthquake Located
Locations are triangulated
Three location must measure the earthquake

5. Earthquake Magnitude Old way of measuring: New way:
Richter Scale
New way:
Moment magnitude
Same basic scale, different method for calculating
Moment Magnitude considers other factors such as measurements of fault movement

6. Mercalli Scale
Measures intensity based on damage and observation at a specific location

7. Liquefaction Phenomenon where the ground behaves like fluid during an
earthquake

8. Tsunamis A seismic wave in the ocean caused by the displacement
of water

9. Assignment WRITE OUT ALL QUESTIONS AND ANSWERS Pg 221 #1-4
Pg 229 Inferring
Pg 232 #2, 4
Pg 233 Inferring
Pg 237 #3, 6