1. Earthquakes – Day 1
October 11, 2010

2. Objectives
I will be able to describe an earthquake’s _________such as epicenter, focus, magnitude, and intensity
I will be able to analyze the ____________of seismic earthquake waves
I will be able to determine earthquake ____________from a travel-time __________

3. Key Points
To describe the location of earthquakes, we use the terms focus and epicenter
When analyzing how earthquakes travel, we talk about the 3 main types of earthquake waves: s, p, and surface
These waves travel at different speeds and cause differing amounts of destruction
The magnitude of an earthquake measures the amplitude of the largest wave
Major earthquakes can be preceded by foreshocks and followed by aftershocks
The intensity of an earthquake describes the amount of shaking at a specific location

4. What are Earthquakes? Earthquake video Take note of at least 4 facts
______________________

5. Cause of Earthquakes What causes earthquakes to occur?
Where do we usually find earthquakes occurring?

6. Cause of Earthquakes
Earthquakes are the __________or _______of the Earth produced by the rapid release of _____
When rocks are subjected to large forces, such as those associated with plate movement, the rocks are __________and _______________
When rocks cannot withstand the stress any longer, they __________and energy is _________
________are fractures in the earth where movement has occurred
______________ __________ ___________

7. Earthquake features 1. Location
_____: the place where the earthquake starts- _________________
Energy radiates out in _____________
__________: the location on the surface of earth directly __________________

8. Earthquake features
2. _____________: smaller earthquakes that _______or __________________major earthquakes
3. ____________: smaller earthquakes that occur ____________ major earthquakes
4. _____________: the amount of shaking produced by an earthquake at a given location
5. _____________: the “______” of the earthquake
- Richter magnitude: determined from the _________ (height) of the largest seismic wave
- Moment magnitude: determined from the displacement (movement) of the fault zone

9. Earthquake Waves
All of the above features are a result of the earthquake _________that transport the ___________from the ______outward in ____ ____________________
______ general categories
_________________: travel along Earth’s surface
_______________: travel from the focus __________Earth’s ____________

10. Earthquake Waves Surface waves Travel along Earth’s ___________layer
Their motion is _____________
Like waves move a ship on the ocean
Up/down and side-to-side motion
The ________________type of earthquake wave
Because they travel along the ground they cause ______________resting on the land to __________

11. Earthquake Waves Body waves- 2 types 1. P-waves
__________waves- they arrive _______
Travel the _____________
Classified as “compressional waves”- _____________________________
Can travel through __________, ___________, and _____________

12. Earthquake Waves Body waves 2. S-waves
_______________________waves- they arrive ___________P-waves
Travel more __________than P-waves
Travel at right angles to the direction they move
Travel through _________________

13. Check In – Answer the following on a SEPARATE piece of paper in COMPLETE sentences:
What is the epicenter of an earthquake?
What is the source of an earthquake called?
What are the smaller earthquakes that precede major earthquakes called?
Which type of seismic wave travels the fastest?
Which type of seismic wave travels the slowest?
Which type of seismic wave causes the most destruction?

14. Locating Earthquakes- Part I
Because P-waves and S-waves travel at ________________we can use the _________ in their ___________at a given location to figure out the distance to the earthquake’s ______________________
This information is presented in a __________________________

15. Reading Travel-time graphs
A. ________________for the arrival of the waves
B. ___________from the recording station to the _____________________
____________at the top
_________at the bottom