The Geosphere - Lesson 5

Lesson 5

What is an earthquake? a) Movement in the tectonic plates c) A good excuse to call in the Avengers b) An attack of the “Decepticons” d) A shift in the inner core of the Earth

What is an earthquake? a) Movement in the tectonic plates

Earthquakes The upper part of the Earth’s crust is pretty breakable. When it is under “stress” from movements below it can break; this is an earthquake.

Has anyone experienced And earthquake first hand?

Does anyone know where earthquakes occur?? Use the for YES Or the for NO

Where? Use the tools to write on the board and tell us. Keep in mind I’m able to see who writes everything . You can select your color.

Earthquakes Earthquakes happen along boundaries (usually transform boundaries).

Transform boundaries: A fault.

Transform boundaries: What type of movement do the plates have at a transform boundary? Type in the chat box and tell me.

Transform boundaries: A fault. When the plates move horizontally (one moves one way the other moves the opposite).

Earthquakes Earthquakes happen along boundaries (usually transform boundaries). When the rock breaks energy is released, this is called seismic energy or waves.

No dude… not this type of wave but a wave of energy… Yeah man… this type of wave.

Earthquakes When the rock breaks energy is released, this is called seismic energy or waves. “A seismic wave is any ground movement that results from energy released during an earthquake. The point in the Earth’s crust where the rock ruptures is the focus. The point on Earth’s surface directly above the focus is the epicenter.“ In our lab today we will be looking for the location of the “epicenter” using the data we’re given.

Two main types of waves: 1.) Body waves 2.) Surface waves

Two types of body waves: P waves S waves

Grab something to take a FEW notes on! Notes alert! Grab something to take a FEW notes on!

Body waves: P-wave What does the “P” stand for? Any ideas?

Body waves: P-wave They are called: Primary waves or compression waves

Body waves: P-wave What layer is liquid? They are called: Primary waves or compression waves Travel through the solid and liquid parts of Earth What layer is liquid?

Body waves: P-wave They are called: Primary waves or compression waves Travel through the solid and liquid parts of Earth Fastest earthquake waves Always the first waves to appear on a seismogram

Body waves: P-wave They are called: Primary waves or compression waves Travel through the solid and liquid parts of Earth Fastest earthquake waves Always the first waves to appear on a seismogram Cause ground to move horizontally back and forth through compression.

Body waves: s-wave What does the “S” stand for?? Thoughts?

Body waves: s-wave These are called: Secondary waves or shear waves

Can you name the solid layers? Body waves: s-wave These are called: Secondary waves or shear waves Can travel through Earth’s solid portions only Can you name the solid layers?

Body waves: s-wave These are called: Secondary waves or shear waves Can travel through Earth’s solid portions only When they hit the liquid outer core, S-waves are no longer able to be detected. S-waves are absorbed at the core.

Body waves: s-wave These are called: Secondary waves or shear waves Can travel through Earth’s solid portions only When they hit the liquid outer core, S-waves are no longer able to be detected. S-waves are absorbed at the core. Cause ground to move back and forth in an S-shaped pattern

Just in case you were wondering… Surface waves: When the “P” and “S” waves make it to the surface of the Earth they are transformed into: Surface Waves And then called: R-waves (Rayleigh waves) Cause lots of damage to the surface of the Earth, especially to buildings Have a rolling motion, like the waves of the ocean L-waves (Love waves) Have a side-to-side motion similar to the movement of a snake

Lets do this!

Go to the lab

Follow step 1 and 2

Let’s do this!!!

When you are done viewing the “introduction” come back to this view and click on the

Lets write our hypothesis

Use the lab sheet Write in your hypothesis. How can we use the seismic waves to find the epicenter (the point on the surface of the Earth where the earthquake started)?

When you are done writing your hypothesis come back to this view and click on the

How to read your seismogram:

Pick your seismograph and we will go through this together.

Press on: <Ctrl> and <PrtSc> to take a “screen shot”

Use the lab sheet Paste your screen shot HERE!

Lets find the epicenter

Now we need to plot this data…

Press on: <Ctrl> and <PrtSc> to take a “screen shot”

Make sure you finish the questions

Don’t forget to turn it in

Submit your work!