earthquakes ppt for class
DESCRIPTION
This is the earthquake power point you saw in class. Feel free to take notes on it or view the animations again.TRANSCRIPT
![Page 1: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/1.jpg)
Earthquakes
Adapted from powerpoint by Liz LaRosa http://www.middleschoolscience.com 2009
What Is An Earthquake? Click here to find out
![Page 2: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/2.jpg)
What is an earthquake?• Used to describe both sudden slip on a fault, and the resulting
ground shaking and radiated seismic energy caused by the slip• Caused by volcanic or plate activity,
The map above shows the distribution of earthquakes with magnitudes greater than 5.0 that occurred between 1965 and 1995.
http://eqseis.geosc.psu.edu
![Page 3: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/3.jpg)
Three Types of Faults
Strike-Slip
Normal
Reverse
Animation of fault movement
![Page 4: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/4.jpg)
Normal fault
Pulls on the crust stretching rock so that it becomes thinner (like pulling on bubble gum) = tensionOccurs when plates are moving apart
Results in hanging wall slipping downward
Hanging wall
Foot wall
animation
![Page 5: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/5.jpg)
What type of fault?
Hanging wallFoot wall
http://www.bgs.ac.uk/eqr/GeoD_Structures.htm
normal
![Page 6: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/6.jpg)
What causes earthquakes?
• Tectonic plates move past each other causing stress. Stress causes the rock to deform– What type of fault boundary is this?– What type of stress is shown?
transform
shearing
![Page 7: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/7.jpg)
Strike – slip fault
Rocks on either side of fault slip past each other sideways with little up or down motion -
Animation of strike-slip motion
Occurs at a plate boundarytransform
shearingWhat type of stress is produced?
![Page 8: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/8.jpg)
Fault rupture across road in western Kaynasli, right-lateral strike slip displacement was about 4.0 m (13 feet) at this location http://www.geerassociation.org/GEER_Post%20EQ
%20Reports/Duzce_1999/kaynasli1.htm
![Page 9: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/9.jpg)
Reverse fault
Pushes on the crust squeezing rock until it folds or breaks (like a trash compactor) = Occurs when plates are moving together
Results in hanging wall slipping upward
Hanging wall
Foot wall
animation
compression
![Page 10: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/10.jpg)
What type of fault?
Hanging wall
Foot wall
http://geologicalintroduction.baffl.co.uk
reverse
![Page 11: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/11.jpg)
What type of fault?
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
![Page 12: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/12.jpg)
– 1. point inside the Earth where an earthquake begins
– 2. point on Earth’s surface above focus where earthquake is FELT most strongly
Epicenter
Focus
1
2
![Page 13: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/13.jpg)
How Seismographs Work
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
the pendulum remains fixed as the ground moves beneath it
A seismograph is an instrument used for recording the intensity and duration of an earthquake.
![Page 14: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/14.jpg)
Earthquakes
• How are earthquakes measured?
Seismograph machine
Seismogram – seismic wave display record
![Page 15: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/15.jpg)
Seismic Waves
![Page 16: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/16.jpg)
Primary Waves (P Waves)
• A type of seismic wave that compresses and expands the ground
• The first wave to arrive at an earthquake
http://daphne.meccahosting.com/~a0000e89/insideearth2.htm
![Page 17: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/17.jpg)
Secondary Waves (S Waves)
• A type of seismic wave that moves the ground up and down or side to side
http://daphne.meccahosting.com/~a0000e89/insideearth2.htm
![Page 18: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/18.jpg)
Comparing Seismic Waves
![Page 19: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/19.jpg)
Surface Waves
• Move along the Earth’s surface• Produces motion in the upper crust
– Motion can be up and down– Motion can be around– Motion can be back and forth
• Travel more slowly than S and P waves• More destructive
Animation of wave types
![Page 20: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/20.jpg)
How do scientists calculate how far a location is from the epicenter of an earthquake?
• Scientists calculate the difference between arrival times of the P waves and S waves
• The further away an earthquake is, the greater the time between the arrival of the P waves and the S waves
![Page 21: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/21.jpg)
Typical Seismogram
http://isu.indstate.edu/jspeer/Earth&Sky/EarthCh11.ppt
startstart finishfinish
How much time elapsed between the arrival of the P wave (start) and the arrival of the S wave (finish)?
![Page 22: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/22.jpg)
Locating Earthquakes
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
![Page 23: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/23.jpg)
Locating Earthquakes
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
![Page 24: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/24.jpg)
Now you are going to be seismologists and locate an Earthquake
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
Go to: http://tinyurl.com/11quake13
Click here to go to virtual earthquake site
![Page 25: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/25.jpg)
National Geographic earthquake information
![Page 26: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/26.jpg)
How are Earthquakes Measured? Richter Scale
A logarithmic scale used to express the total amount of energy released ___________ of an earthquake. Its values typically fall between 0 and 9, with each increase of 1 representing a _________ increase in energy.
magnitude
10-fold
![Page 27: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/27.jpg)
How are Earthquakes Measured? Mercalli Intensity Scale
Click for Interactive Demo Go to http://tinyurl.com/13quake13
A scale of earthquake intensity based on ___________and ranging from I (detectable only with instruments) to XII (causing almost total destruction).
observed effects
![Page 28: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/28.jpg)
Earthquake Waves & Earth’s Interior
Seismic wave animation
![Page 29: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/29.jpg)
Seismic Waves in the Earth
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
Click here for animation
![Page 30: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/30.jpg)
Tsunamis
http://www.uwgb.edu/dutchs/EarthSC-102VisualsIndex.HTM
Click here for explanation of a tsunami
![Page 31: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/31.jpg)
Formation of a tsunami
http://isu.indstate.edu/jspeer/Earth&Sky/EarthCh11.ppt
PBS –tsunami animation
a large ocean wave usually caused by an underwater earthquake or a volcanic explosion.
![Page 32: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/32.jpg)
Click here for Japan helicopter view of tsunami
With typical waves, water flows in circles, but with a tsunami, water flows straight. This is why tsunamis cause so much damage!
![Page 33: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/33.jpg)
Tsunami Warning System
http://isu.indstate.edu/jspeer/Earth&Sky/EarthCh11.ppt
![Page 34: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/34.jpg)
Review Questions
1. A large ocean wave usually caused by an underwater earthquake or a volcanic explosion.
tsunami
2. Used to describe both a sudden slip on a fault, and the resulting ground shaking and radiated seismic energy caused by the slip
earthquake
![Page 35: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/35.jpg)
How are Earthquakes Measured?
3. Which one uses a logarithmic scale to express the total amount of energy released or magnitude of an earthquake.
Richter Scale
4. Which uses a scale of earthquake intensity based on observed effects and ranging from I (detectable only with instruments) to XII (causing almost total destruction).
Modified Mercalli Scale
![Page 36: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/36.jpg)
What type of fault is shown by each picture?
1.2.
3.
NormalReverse
Transverse or strike-slip
![Page 37: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/37.jpg)
Which type of wave travels through solids only?
S-wave
![Page 38: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/38.jpg)
Which type of wave causes the most destruction?
Surface or Love waves
![Page 39: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/39.jpg)
What type of fault?
AHanging wall has moved
http://geologicalintroduction.baffl.co.uk B
Source: indiana.edu
Reverse fault
upwardStrike –slip or transverse fault
![Page 40: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/40.jpg)
– 1. point inside the Earth where an earthquake begins
– 2. point on Earth’s surface above focus where earthquake is FELT most strongly
Epicenter
Focus
1
2
![Page 41: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/41.jpg)
People walk along a damaged road in the province of Bohol on Tuesday, October 15, 2013.
Do you think this was a major earthquake? Why or why not?
![Page 42: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/42.jpg)
Yes, it was a major quake.It crumbled a number of buildings
Such as this church
7.1 magnitude earthquake hit the Philippines
![Page 43: Earthquakes ppt for class](https://reader033.vdocuments.us/reader033/viewer/2022061418/554a362fb4c90520578b55b3/html5/thumbnails/43.jpg)
Earthquakes
5. __________ machine
____________ seismic wave display record
Seismograph
P-wave
Surface
2.
3.
4.
1. S-wave
Seismogram