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Unit 7: Geology: Earthquakes and Review
EARTHQUAKES 101: Part III
Seismic Waves: Conclusion
1. We have never “seen” the ___________________ of Earth, but waves help show us what is there.
2. The idea that Earth is made of __________________________ and different types of material was supported by studying the motion of seismic waves.
Epicenter
3. Remember, __________________ pass through __________________________________.
4. ______________________ pass only through _____________________.
P and S
P and S
P and S
P and S
P only
P only
Example:
P only
- S waves do not travel to the other side of Earth they can not get through the liquid mantle.
- The more dense the substance the waves is traveling through the faster the wave goes. (We figure out density of interior Earth).
Measuring Earthquakes
Scientists have two ways of measuring earthquakes:
- ______________________
- ______________________
Richter Scale
1. A scale that measures the _________________ of the largest ___________ recorded on a seismogram.
2. The wave amplitude increases by __________________________ magnitude increase on the scale.
3. Example: A Mag ___ earthquake has waves ____________________________ than a Mag _____.
4. This scale is the most common used to report the strength of an earthquake.
5. The higher the magnitude of the wave, the _____________________ the earthquake.
2 – Generally not felt by humans.
3
4 – Felt by most humans.
5
6 – Destructive in populated regions.
7
8 – Great earthquakes; very destructive.
9
10 – Never recorded this high.
Mercalli Scale
1. A scale that measures the ______________________________ that occurs after an earthquake.
2. Not very common.
Hazards from Earthquakes
1. ________________: gas lines breaking.
2.
________________: when water-filled ________ act like “flowing ______________” and __________________ due to the shaking of the ground.
- The buildings ____________ off their foundation and collapse.
- The soils shake and _________________ so much that they act like liquids rather than solids.
3.
________________: __________ produced from ____________________ earthquakes (NOT A TIDAL WAVE).
- Movement along a _____________ underwater causes _______________________________ of water (hanging wall moves up or down).
- The energy release ______________________ upward forming a large wave.
- While at sea, the wave is not really that noticeable.
- As it approaches the shallow water near the coast, the water is _________________________ forming a huge ___________ > 90 feet tall at times.
Study Guide:
1. Review all N/S guides on earthquakes and be able to answer the homework questions (and worksheet questions).
2. Take practice earthquake test on website.
3. Make sure you pay special attention to the following concepts, ideas, content areas, etc:
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Define an earthquake and describe what causes them to form.
What is a fault and how does one form?
Describe what is meant by the elastic limit of rock.
What are the three types of forces that form faults? What are the three types of faults?
Be able to identify a hanging wall and a footwall.
Be able to identify a fault type by looking a diagram (like the homework).
What are seismic waves and how are they created?
What is a focus and what is an epicenter. Identify them.
Know the three types of waves and ALL THE CHARACTERISTICS OF EACH that we went over in class.
What is a seismograph and a seismogram and what can we learn from them.
Be able to read a time-travel graph. What does a time travel graph tell us?
What is triangulation and how does it work?
What other things can we learn from seismic waves?
How do we measure earthquakes? What are the major hazards that occur as a result of earthquakes?
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Created with EclipseCrossword — www.eclipsecrossword.com
Across
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Force that causes a reverse fault
Fastest type of wave
type of energy caused by the movement of a fault
Side by side motion seen in transform faults
Scale from 1 to ? that tells the magnitude of an earthquake
How we describe a fault when it cannot move due to friction
small earthquake after a bigger earthquake
Where movement first occurs along a fault
Giant sea wave caused by underwater earthquake
The rock that is below the fault
Type of seismic wave that travels through only solids
Force that causes a normal fault
Scale that measures earthquake damage
Area along a fault that is due for a big quake
Down
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Last type of wave recorded on the seismogram
Place on Earth's surface directly above the focus
Print out from a seismograph
The rock that is above the fault
Branch of science devoted to earthquakes
Bigger than usual quake that 'predicts' a bigger quake
Crack in the Earth's crust where movement occurs
Occurs when soil and groundwater mix
This is also known as a transform fault