1. Earthquakes

2. Do Now: Copy the following statements and state whether you agree or disagree with them.
1. Earth’s crust is broken into rigid slabs of rock that move, causing earthquakes and volcanic eruptions.
2. Earthquakes cause energy waves that travel through Earth.
3. Earthquakes can be predicted.

3. Quiz Review (Cambridge): The Theory of Plate Tectonics
10 points total
Convection currents in the mantle produce a force that causes motion called basal drag. Convection currents inside the asthenosphere can drag the lithosphere. The rising mantle at mid-ocean ridges causes plates to move away from the ridge with a force called ridge push. At a convergent plate boundary, a force called slab pull pulls on a plate as one edge of the plate sinks into the mantle.
Lithosphere
Asthenosphere
Convergent
Divergent
Transform
Earth’s surface is made of plates that move with respect to one another.

4. Quiz Review (Comprehensive): The Theory of Plate Tectonics
9 points total
B. transform plate boundary
8/9 = 88.9%, B
B. rising mantle at a plate boundary.
7/9 = 77.8%, C
6/9 = 66.7%, D
C. divergent plate
5/9 and below = 55.6% or less, F
B. convergent plate
A plate tectonics
D. slab pull
C a layer of crust and solid upper-most mantle
A. convection
C. a plastic layer of rock in the mantle

5. Quiz Retake Requirements
<80% on original quiz
Completion of Additional Targeted Practice – Plate Tectonics worksheet

6. Earthquakes
Objectives: Students will be able to define an earthquake, describe where earthquakes occur, and describe how scientists monitor earthquake activity.
Standards: SC.7.E.6.5, SC.7.E.6.7, SC.7.N.1.3, SC.7.N.1.5, SC.7.N.1.6

7. Essential Questions (copy these down)
What is an earthquake?
Where do earthquakes occur?
How do scientists monitor earthquake activity?

8. Vocabulary earthquake fault seismic wave focus epicenter primary wave
secondary wave
surface wave
seismologist
seismometer
seismogram

9. Homework due 2/14 Key Concept What is an earthquake?
Use your textbook and notes to complete.

10. What are earthquakes?
Earthquakes: vibrations caused by the rupture and sudden movement of rocks along a break or a crack in Earth’s crust.
Terremoto: vibraciones causadas por la rupture y el movimiento repentino de las rocas en una fractura o grieta en la corteza de la Tierra.

11. What are earthquakes?
The forces that move tectonic plates also push and pull on rocks along the fault.
Earthquakes result from the buildup and release of stress along active plate boundaries.
The greater the force, the greater the chance of a large and destructive earthquake.

12. Where do earthquakes occur?
Records show that most earthquakes occur in the oceans and along the edges of continents.
The deepest earthquakes occur at subduction zones (where plates collide along a convergent plate boundary and the denser oceanic plate subducts into the mantle).
These earthquakes release tremendous amounts of energy and can be disastrous.
Where do earthquakes occur?

13. Where do earthquakes occur?
Shallow earthquakes are common where plates separate along a divergent plate boundary.
They can also occur along transform plate boundaries, like the San Andreas fault in California.
Earthquakes of varying depths occur where continents collide

14. Stand Up, Hand Up, Pair Up: In your own words, answer the following question.
Partner A: What is an earthquake?
Partner B: Where do earthquakes occur?

15. Faults Rock deformation can result in ground displacement.
A fault is a crack or a fracture in Earth’s lithosphere along which movement occurs.
Falla: grieta o fractura en la litosfera de la Tierra en la cual ocurre el movimiento.
When rocks move in any direction along a fault, an earthquake occurs.

16. Types of Faults
Strike-slip fault: Two blocks of rock slide horizontally past each other in opposite directions.
Location: transform plate boundary

17. Types of Faults
Normal fault: forces pull two blocks of rock apart. One block moves down along the fault relative to the other.
Location: divergent plate boundaries

18. Types of Faults
Reverse fault: forces push two blocks of rock together. One block moves up along the fault relative to the other.
Location: convergent plate boundaries.

19. Types of Faults

20. Parts of an earthquake
When rocks move along a fault, they release seismic waves: energy that travels as vibrations on and in Earth.
Onda sismica: energia que viaja en forma de vibraciones por encima y dentro de la Tierra.
Focus: a location inside Earth where seismic waves originate and rocks first move along a fault and from which seismic waves originate.
Foco: lugar en el interior de la Tierra donde se originan las ondas sismicas, las cuales son producidas por el movimiento de las rocas a lo largo de un falla.

21. Parts of an earthquake
Epicenter: the location on Earth’s surface directly above the earthquake’s focus.
epicentro: lugar en la superficie de la Tierra justo encima del foco de un terremoto.