Earthquakes Day 1

What do you think about when you see this picture?

At the end of the topic you should be able to...

• describe how crustal deformation by plate tectonics causes earthquakes

• model the crustal deformation of Earth that causes earthquakes

• explain the tools scientists use to study earthquakes

• describe the relevance of studying earthquakes

What would you do if you were in an earthquake?


Have you ever been in an earthquake before?

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​What would you do?

Where do earthquakes occur?

Based on the image, you can see that the majority of earthquakes occur on the major plate boundaries. There are also many, smaller plate boundaries where the other earthquakes occur. 

​https://earthquake.alaska.edu/earthquakes/recent_list

The majority of earthquakes occur when the tectonic plate's boundaries move quickly against each other (slide past, pull apart or come together).

The star is where the earthquake started (called focus), the circle are the seismic waves that are released. 

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HOW? Do earthquakes occur?

An earthquake begins at the focus where the ground ruptures.

The focus is located on the pre-existing fault

Focus

​The seismic waves travel outward in ALL directions from the focus

Waves

The point ON Earth's surface directly above the focus is the epicenter of the earthquake.

Epicenter

If you know where it is go and find your slinky from your science kit.

Think about this: 

Slinkies can help us learn about earthquakes!

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Slinky!

P-waves for short

Compressional

Move in a left to right motion

FIRST wave to occur after an earthquake

Primary Waves

​S-waves for short

SECOND fastest waves

Occur farther away from the fault

Move in an up and down motion

​​Secondary Waves

Click on the link and then click on the earth to view the 2004 Sumatra Quake and Tsunami. 

Look at the different seismic waves that travel through the earth (P waves and S waves).

Which waves travel through the Mantle, Outer and Inner Core? Which waves only travel through the mantle? 

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Seimic Waves Activity

​https://ds.iris.edu/seismon/swaves/index.php