1. How many, how often do earthquakes occur each year?
Read Section 10.1 (pp.214-5) and complete the following notes in your note books
How many, how often do earthquakes occur each year?
An earthquake is a Caused by a release of......
EQ’s due to: ________, _________, _________, _______
4. *MOST EQ’s are caused by......
Define a fault:
___________ prevents the plates from moving.
The elastic rebound theory
What /where is the focus of an earthquake?
Where is the epicenter of an earthquake?
Shallow EQ depths of 30 km are at __________ boundaries
Deep EQ depths of 700 km are at ___________ boundaries

2. Earthquake Scavenger Hunt for EXTRA CREDIT
Find the following at:
Largest earthquake in the world, ever.
Largest earthquake in U.S.
Country with the most earthquakes.
Where are most earthquakes located?
Which plate boundary has the largest, deepest EQs?
Where was the most recent EQ? (today)
Where is the New Madrid fault zone?
What causes a tsunami? How high can they get?
1. Chile Alaska Indonesia or Japan 4. Around the Ring of Fire 5. Along convergent subduction boundaries (O-C) 6. (varies per day) 7. southeastern Missouri, northeastern Arkansas, and adjacent parts of Tennessee and Kentucky 8. Tsunamis are ocean waves caused by large earthquakes and landslides that occur near or under the ocean; a small tsunami can be 6 feet tall, normally max out at 100 ft, and the tallest recorded was 1720 feet tall and happened in Alaska in 1958

3. Where do most of the world’s earthquakes occur?
Go to classzone.com
Choose High School Earth Science in IL
Choose our book
Click Go to Website
Fill in the code ES1001
Answer the questions on your sheet
Most occur around the “Ring of Fire” circling the Pacific Ocean plate O-C, O-O

4. What is an Earthquake?

5. Earthquakes are… Vibration of Earth produced by the rapid release of…
ENERGY
Energy in the form of Mechanical waves that move through Earth’s crustal rock
Waves move out from source in ALL directions, like water waves moving through water. Enough ENERGY to destroy an entire city!
The movement of energy from an earthquake is like...

6. Causes of earth “quaking”
Nuclear bomb explosion Cavern collapse volcanic eruption meteor impact
Any large energy event can cause Earth to “shake” but what causes earthquakes?

7. How and where “Natural” Earthquakes form
Begin unit showing NOVA’s video on youtube: “Deadliest EQ’s” (53 min). Everyday check current world EQ’s at USGS
USGS real-time EQ’s

8. Earthquakes are caused by the motion along plate boundaries
Most EQs are caused by the release of stress/strain at plate boundaries

9. Convergent boundary
At convergent boundaries the ocean plate plunges under the continental plate They scrape and produce large amounts of friction and deep earthquakes.

10. Transform boundary
A FAULT : where the opposing (shearing) motion between two lithospheric plates moving in opposite direction

11. Earthquakes occur at faults as plates move
Laterally: strike-slip fault
Down: normal fault
Up: thrust fault
(Types of stress on rocks)

12. San Andreas Fault
A break in the lithospheric crust along which movement occurs.
San Andreas fault is not one fault, but a series of faults that span several hundred miles
(3 min)

13. New Madrid Fault zone

14. Illinois has many faults and fractures, most in southern Illinois

15. New Madrid Fault Zone
Under the sedimentary rock strata lies a series of ancient faults that shift and settle causing earthquakes

16. What affects plate
movement intensity?

17. Do the Spaghetti Strike-slip Fault Investigation
Potential Energy: stored energy (tension caused by the friction between the slow [2-10cm] movement of the plates/at fault lines [initial energy for movement is coming from the heat of the Earth’s core-convection in the asthenosphere causes lithospheric movements])
Kinetic Energy: motion energy (when the “tension pops” and we feel the resulting movement of the plates slipping and then returning to no longer being “stretched” [elastic rebound])

18. (leave about 5 lines maximum for notes)
Elastic Rebound
Theory
(leave about 5 lines maximum for notes)
Elastic Rebound demonstrated with Sandpaper Blocks

19. Stress and strain builds along faults Friction prevents the plates from moving easily
Amazingly, rock will bend and deform under heat and pressure

20. Elastic rebound
Use a plastic ruler to demonstrate this.

22. https://www. youtube. com/watch

23. EQ prediction https://www.youtube.com/watch?v=gFB-qpiKccs

24. The story so far…
Two tectonic plates do not flow past each other smoothly, but rather the faults that form their boundaries tend to stick or lock up for years at a time due to friction.
Each year the portions of plates near locked faults move slowly a few millimeters and deform elastically.
The more the plates are stretch and deformed, the greater the force is on the fault (shear stress).
Eventually the force is sufficient to overcome the friction and make the plates break free of one another
The elastic energy that has been stored up is released and the ground vibrates. (seismic waves).
This process of faulting is called stick-slip or elastic rebound. 

25. Energy from earthquakes moves in mechanical waves…
P and S Waves
Energy from earthquakes moves in mechanical waves…

26. Anatomy of an Earthquake:
Focus: the point in the earth’s crust that moves /shifts Epicenter: the location on the earth’s surface above the focus.
Focus can be near the surface (a couple km or very deep 600 km)

27. Like the ripples in water, the waves spread out from the epicenter in all directions

28. Earthquake Seismic waves
2 Types;
Body waves
Surface waves
Click on link first
Do you remember when we talked about P and S waves before?

29. Velocity of P and S waves are different with depth and material
Asthenosphere
Mantle
Outer core
Inner core

30. Body Waves (pg 215) travel through the earth
Copy this T chart in your notes and start filling in the information found below.
Body Waves (pg 215) travel through the earth
Primary (P) waves Secondary (S) waves
Compression waves, push, pressure
Changes the density, volume of rock as it passes through.
Pass thru solid, (molten), liquids, gas
Arrives first, fastest ≈6 km/s
* (depends on the density of rock – faster in more dense material [slows in liquid])
Transverse, “S” snake, side-to-side
Changes the shape of rock as it passes through.
Passes through Solids only
Arrives second, slower ≈3.5 km/s
* Is more destructive

31. P waves compress the rock’s volume as it travels

32. S waves change the shape of the rock up and down

33. Earthquake waves
2 Types;
Body waves
Surface waves

34. Surface waves travel along the surface, tossing structures up.