2. Warm up 9/27/2016 ( 10 min) Label the diagram A-G Volcano B. trench
C. Oceanic crust
D. asthenosphere
E & F. Continental crust
G. Subduction

3. Objective and EQ 2.1.1 Describe the anatomy of an earthquake.
EQ- How do seismic waves move?

4. SEISMIC WAVES
Seismic waves are the vibrations (waves) of energy released by a quake!
Two Types
Body Waves
Surface Waves
Seismology is the study of earthquakes and seismic waves. 4

5. 1st type BODY WAVES (P and S)
P WAVES (P= Primary)
- Fastest (6 km/s)
- Causes ground to squeeze and stretch like a spring!
- Can travel though solids, liquids, & gas
Cause ground to compress and stretch in direction in which wave is travelling. 5

6. BODY WAVES (P and S) S WAVES (S= Secondary) - Slower (3.5 km/s)
- Can travel though solids (not liquids)
Also known as shear waves. Cause ground to compress and stretch at right angles to direction of wave’s motion. 6

7. 2nd Type Surface Waves
Surface Waves travel along the earth’s surface. Larger than body waves and most destructive
Love Wave: Lateral movement of the surface
Rayleigh Wave: Rolling movement of the surface (similar to an ocean wave)

9. Seismic Wave Review
P Waves
S Waves
Surface Waves

10. Recording Seismic Waves
Seismograph:
An instrument that measures the horizontal or vertical motion of Earth’s surface
Seismograms:
Shows all three types of seismic waves—surface waves, P waves, and S waves

11. Major Hazards of Earthquakes
Building Collapse
Landslides/Mudslides
Fire
Tsunamis (Not Tidal Waves!)

12. Pair Work What are the different kinds of seismic waves?
Types of seismic waves Chart
If you haven’t completed the fault worksheet, please work on that as well.

13. WARM UP 9/28/2016
If there was news that an earthquake or (any natural disaster) was headed for Charlotte, NC, what are some things you and your family would need in your emergency kit?

15. Agenda Warm up 1906 San Francisco Earthquake
Notes on Measuring Earthquakes
Lab on Finding Epicenters

16. 1906 San Francisco Earthquake

17. Objective
EEn Predict the locations of volcanoes, earthquakes, and faults based on information contained in a variety of maps.

18. Essential Question
How can I locate the epicenter of an earthquake?

19. Epicenter located using three seismograph stations
The point where the three circles meet is the location of the earthquake epicenter.

20. Locating an Earthquake

21. When an earthquake happens, scientists want to know where it happens.
Scientists need to find the epicenter. Scientists need to find the source.
Epicenter = Distance in the Difference in TIME between the P wave and the S wave!! -

22. HOW SCIENTISTS USE THIS
SCENARIO 1: Watch the watch! What’s the time difference?
Answer 1 _____________________
SCENARIO 2: A P Wave arrives at the seismograph station 3 minutes after an earthquake. An S Wave arrives 8 minutes after an earthquake. What is the difference in arrival time?
Answer 2 ______________________
SCENARIO 3: At 10:32 a P Wave arrives. At 10:45 and S Wave arrives. What is the difference in arrival time?
Answer 3 _______________________

23. SCENARIO #1
Determine the difference in the travel-times between the first P wave and the first S wave, if the seismic station is 1500 miles from the epicenter.
Read the problem and box in key words.
Identify the information on the axis.
Plot your points to find data. ________________________
Subtract your data.
__________ - __________ = _________

24. SCENARIO #2
Determine the difference in the travel-times between the first P wave and the first S wave, if the seismic station is 500 miles from the epicenter.
Read the problem and box in key words.
Identify the information on the axis.
Plot your points to find data. ________________________
Subtract your data.
__________ - __________ = _________

25. SCENARIO #3
Determine the difference in the travel-times between the first P wave and the first S wave, if the seismic station is 2,000 miles from the epicenter.
Read the problem and box in key words.
Identify the information on the axis.
Plot your points to find data. ________________________
Subtract your data.
__________ - __________ = _________

26. Measuring the size of earthquakes
Two measurements describe the size of an earthquake
Intensity – a measure of earthquake shaking at a given location based on amount of damage
Magnitude – estimates the amount of energy released by the earthquake

27. Earthquake Magnitudes

28. Intensity scale
Modified Mercalli Intensity Scale was developed using California buildings as its standard

29. Based on amplitude of largest seismic wave recorded
Magnitude scales
Richter scale
Based on amplitude of largest seismic wave recorded

30. Richter Scale Magnitude Level Earthquake Effects
Estimated Number Each Year
less than 1.0 to 2.9
generally not felt by people, though recorded on local instruments.
More than 100,000
felt by many people; no damage
12, ,000
felt by all; minor breakage of objects
2,000-12,000
Some damage to weak structures
200-2,000
moderate damage in populated areas.
20-200
8.0 or higher
serious damage over large areas; loss of life
severe destruction and loss of life over large areas
3-20
Fewer than 3

31. 7.8 magnitude (China, 2008)

32. 7.0 Haiti 2010

33. Japan, 2011, one of the most massive earthquakes in history, measuring 9.0 on the Richter scale

34. Tsunamis Destructive “tidal waves”
A tsunami is triggered by an earthquake.
A tsunami also can occur when the vibration of a quake sets an underwater landslide into motion.
Tsunami is the Japanese word for “seismic sea wave.”

35. Formation of a tsunami
Tsunamis are actually huge, extending from the fault on the sea floor up to the surface, but they don’t stick up more than a meter or so in the deep ocean. However, when they reach shallow water they must rear up and slow down. Discussion: Kinetic vs. potential energy