1. DO NOW
Pick up notes sheet and Review #15.

2. REVIEW How is earthquake intensity different from magnitude?
Richter OR
Moment
Magnitude
Modified Mercalli
How is earthquake intensity different from magnitude?
What scale is used to measure each?
How were we able to use newspaper articles to pinpoint the epicenter of an earthquake that happened more than 100 years ago?

3. REVIEW
Magnitude measures the strength of an earthquake. It is related to energy released in the earthquake and is determined from measurements on seismographs.
A seismograph is an instrument that measures and records the details of earthquakes.
Intensity measures the strength of shaking produced by the earthquake at a certain location. Intensity is determined from effects on people, human structures, and the natural environment.

4. REVIEW Moment Magnitude Scale – measures the energy of the earthquake.
Based on:
size of the area of the fault that moves.
average distance that the fault block moves.
rigidity of the rocks in the fault zone.
Modified Mercalli – measures the intensity by way of damage or effects of the earthquake.

5. Measuring the energy of earthquakes
EARTHQUAKE MAGNITUDE
Measuring the energy of earthquakes

6. STORED ENERGY
Potential energy stored in rocks that are elastically strained.
This means that the rocks are bent and flexed almost to the point of breaking.

7. STORED ENERGY Stress reaches the point where rocks fracture.
Energy is released (elastic potential becomes mechanical kinetic).
Energy spreads outward in waves (waves carry energy).
Elastic rebound follows.

9. MAGNITUDE: MOMENT MAGNITUDE SCALE
Strength of an earthquake.
Based on the energy released.
There is an exponential increase at each level.

10. MAGNITUDE IS LOGARITHMIC
Each level is 10 times stronger than the previous level.
Bill Nye Video LINK – Explains the Richter Scale

11. MAGNITUDE IS LOGARITHMIC

12. PRACTICE PROBLEMS
If each level is 10 times stronger than the one before it, how much stronger is:
A mag. 3 than a mag. 2?
A mag. 4 than a mag. 2?
A mag. 5 than a mag. 2?
A mag. 5 than a mag. 4?
A mag. 6 than a mag. 3?
A mag. 8 than a mag. 6?
1- 10 times
times (10 X 10)
3 – 1,000 times (10 X 10 X 10)
4 – 10 times
5 – 1,000 times (10 X 10 X 10)
6 – 100 times (10 X 10)
Trick to calculate:
How many levels?
You need that many zeros!

13. PRACTICE PROBLEMS
If each level is 10 times stronger than the one before it, how much stronger is:
A magnitude 3 than a mag. 2?
A magnitude 4 than a mag. 2?
A magnitude 5 than a mag. 2?
A magnitude 5 than a mag. 4?
A magnitude 6 than a mag. 3?
A magnitude 8 than a mag. 6?
10 times
100 times
1000 times
10 times
1000 times
100 times

14. EARTHQUAKES RELEASE ENERGY
Magnitude
Power NYC
Power USA
Lightning Flashes
Gallons of Gasoline
Hiroshima Bombs 4
>0.1 months
12.6
478.0
> 0.1 6
12,619
477,998 1 8
2.2 months
0.2 days
12,619,147
477,997,988
1,006 10
2,199 months
224 days
12,619,146,889
477,997,988,242
1,006,311

15. RECENT EARTHQUAKES

16. REVIEW… Energy that is stored in rocks is a type of: Kinetic Energy
Elastic Potential Energy
Gravitational Potential Energy
Fracture energy

17. ACTIVITY: PLOTTING EARTHQUAKE MAGNITUDE
1. Find one partner to do this with.
2. Open one of the following:
Smartphones – Earthquake app
iPhones: Quakefeed or iEarthquake
Android: EQ Info Global Earthquakes
Website:

18. ACTIVITY: PLOTTING EARTHQUAKE MAGNITUDE
3. Get data for all earthquakes over 4.0 (change in settings on apps).
4. Plot 25 most recent events.
5. Use latitude/longitude data AND map to place in correct location
6. Color code by magnitude:
4 or 5 – green
6 or 7 – blue
8 or 9 – orange
10 – red
7. Place next to each position:
S = shallow (< 70 km)
I = intermediate (70 – 300 km)
D = deep (> 300 km)

19. ACTIVITY: PLOTTING EARTHQUAKE MAGNITUDE
Look up the earthquakes
Plot them on your map with the right color and an S, I or D.
Color code by magnitude:
4 or 5 – green
6 or 7 – blue
8 or 9 – orange
10 – red
Place next to each position:
S = shallow (< 70 km)
I = intermediate (70 – 300 km)
D = deep (> 300 km)