1. Word cloud
60 seconds
Wordcloud activity
What comes to mind when you hear the word earthquake?
2. Slide
60 seconds
3. Slide
60 seconds
Forces Within Earth
An earthquake is a sudden and violent shaking of the ground Most earthquakes are the result of tectonic plate movement. However, there are rocks found within plate boundaries that play a large role.
4. Slide
60 seconds
Forces within Continued
Rocks found between plate boundaries resist movement. As they resist, stress builds up. Stress is the total force acting on crustal rocks per unit area. When stress overcomes the strength of the rock, movement occurs along the rock fractures causing an earthquake.
5. Slide
60 seconds
Forces Within Continued
Characteristics of an earthquake are determined by the orientation, magnitude of stress, and strength of the rock. There are three types of stress: compression, tension, and shear.
6. Slide
60 seconds
Forces Within Continued
Types of Stress: Compression-stress that decreases the volume of material. Tension- stress that pulls material apart. Shear- stress that causes the material to twist. As stress occurs on a rock, deformation of material occurs. This deformation is called strain.
7. Slide
60 seconds
When a rock reaches its’ critical point, the rock moves, and energy is released from built-up stress. The energy released causes vibrations that lead to an earthquake. Ex. 2010 Earthquake in Haiti caused by built-up stress
8. Drawings
360 seconds
Create a drawing showing three objects: a squished ball (compression), a stretched rubber band (tension), and two sliding blocks (shear).
9. Slide
60 seconds
Elastic Deformation
Elastic deformation is a physical change in the shape or size of an object in response to a low applied force. It is an example of a reversible physical change. The object returns to its original shape or size when the force is removed. Elastic deformation occurs in many materials, such as rubber bands, springs, steel beams, and rocks.
10. Slide
60 seconds
What is Plastic Deformation?
Plastic deformation is the permanent change in the shape of a material in response to a high applied force. This force must be greater than the yield strength of the material, causing permanent deformation.
11. Open question
150 seconds
What do you infer, is this elastic or plastic deformtion?
12. Drawings
450 seconds
Draw a cow playing electric guitar in a rock concert
13. Slide
60 seconds
Faults
Movement from stress overcoming strength occurs around faults. Faults are weak areas of the crust where fractures are present. A fault plane is where the majority of movement occurs. The movement along faults causes earthquakes. There are three types of fault movement: reverse, normal, and strike-slip.
14. Slide
60 seconds
Fault Movement
Reverse Fault Movement horizontal and vertical compression that squeezes and shortens the crust. This occurs near convergent boundaries. The crust gets closer together after this movement.
Normal Fault Movement Partial horizontal and partial vertical movement causes the crust to move further apart. (divergent) During horizontal movement, rock is pulled apart and stretched. During vertical movement, one side of the fault moves down.
Strike-Slip Movement Horizontal shear stress in separate directions. (transform) Ex. San Andreas Fault
15. Poll
60 seconds
What are vibrations of the ground caused by earthquakes?
- seismic waves
- epicenter
- focus point
- idk
16. Slide
60 seconds
Earthquake Waves
Seismic waves are vibrations of the ground caused by earthquakes. P Waves (primary)- squeeze and pull rocks in the direction of the wave. S waves (secondary)- slow, perpendicular waves compared to direction of movement. Surface waves- the ground moves in every direction causing the most destruction.
17. Slide
60 seconds
18. Slide
60 seconds
Measuring Seismic Waves
The measurement of seismic waves depends on the focus point of the earthquake and the epicenter. Focus point- where earthquakes begin below the surface. Epicenter- where the earthquake begins on the surface
19. Slide
60 seconds
Measuring Seismic Waves
Seismometer is machine that has a frame anchored to the ground and a suspended mass that makes recordings during an earthquake. During an earthquake, the frame vibrates while the suspended mass stays still.
20. Slide
60 seconds
Measuring Seismic Waves
Seismograms record the earthquake.
21. Slide
60 seconds
Earthquake Magnitude and Intensity
Magnitude and Intensity are used to rate earthquakes. Magnitude is the size of something. Intensity is the amount of force. There are three rating scales for earthquakes: Richter scale, movement magnitude scale, and modified Mercalli scale.
22. Slide
60 seconds
Earthquake Magnitude and Intensity
The Richter Scale is a scale that is determined by the height or amplitude of seismic waves. Amplitude moves in factors of ten in this scale. Energy moves in factors of 32 for this scale.
23. Slide
60 seconds
Earthquake Magnitude and Intensity
Movement of Magnitude Scale considers the energy released during an earthquake along with the fault size, the amount of movement, and the rock stiffness.
24. Slide
60 seconds
Earthquake Magnitude and Intensity
Modified Mercalli Scale rates earthquakes with Roman Numerals based on the amount of damage and earthquake intensity. Earthquake intensity is the amplitude of seismic waves. Ex. the more shallow an earthquake, the more intense
25. Slide
60 seconds
Locating Earthquakes
Scientists use arrival of P waves and S waves to determine the epicenter and the time of an earthquake. The arrival of waves determines the possible distance from the station to the epicenter. The time travel of seismic waves along with the distance from the station will determine when the earthquake began.
Made with ❤️ from Norway