Earthquakes and Earth's Layers

Open Ended

Describe what an earthquake is.

Open Ended

Where do earthquakes typically occur?

Multiple Choice

What is the name of the location on the surface directly above where the earthquake occurs?

• Epicenter

• Hypocenter

• Hypercenter

• Circumfrence

Reorder

Reorder the following

• Foreshock

• Mainshock

• Aftershock

1

2

3

• 1
• 2
• 3

Multiple Choice

What causes most earthquakes?

• When plate boundaries get stuck on each other as the plates move.

• Smooth sliding of plates past each other.

• Volcanic eruptions near plate boundaries.

• Bombs and meteors.

Multiple Choice

What kind of waves are released when an earthquake occurs?

• Light waves

• Ocean waves

• Seismic waves

• Heat waves

Open Ended

Explain how scientists record earthquakes and how strong they are.

Multiple Choice

How do scientists locate the origin (starting point) of an earthquake?

• With the use of one seismograph to understand how far away it is from that machine.

• With the use of two seismographs they can pinpoint the earthquakes location by how far away it is from each.

• With the use of three seismographs they can pinpoint the earthquakes location b how far away it is from each.

• They just fly a helicopter around to look for where the most damage is.

Open Ended

Is earthquake prediction possible? Explain

Earthquakes and Earth's Layers

​After reading the article and answering questions, you should now have a better understanding about what they are. Now we are going to learn about how we use them to understand Earth better.

​Earthquakes can cause a lot of destruction and lead to different types of natural disasters, including tsunamis, landslides, and avalanches. Engineers and city planners have to take the probability of the risk factors into consideration before building.

Along with these disasters, they release seismic waves that can be tracked and used to understand the earth's interior structure.

​Seismic Waves

​Pressure waves (aka primary waves aka p-wave)
- travel through solids and liquids
- quickest traveling seismic wave
- travel longitudinally (parallel)
Shear waves (aka secondary waves aka s-waves)
- travel through solids (don't go through liquids well)
- second fastest traveling seismic wave
- travel transversely (perpendicular)

​Lag time - time between P-Wave and S-Wave arrival. The longer the time, the further away the earthquake.

​Bigger squiggles (larger waves) represent stronger earthquakes.

​Earth's Interior

Seismic waves help us understand earth's interior composition and physical properties. As they go through more dense material, they travel faster, which causes them to curve. When they reach a new layer, they change direction completely because it's a different state of matter.

We know the outer core is liquid because S-Waves can't go through it. This is recognized b the S-Wave Shadow Zone on the opposite end of the planet from where the earthquake happened.

​Compositional Layers
-Crust
-Mantle
-Core (Iron and Nickel)

Physical Layers
-Lithosphere (Rigid, Solid)
-Asthenosphere (Soft/Plastic, Solid)
-Mesosphere (Rigid, Solid)
-Outer Core (Liquid)
-Inner Core (Solid)

Multiple Choice

Which of these does an earthquake not usually cause?

• Tsunami

• Avalanche

• Landslide

• Volcanic Eruptions

Multiple Choice

Which of these correctly describes P and S Waves?

• P-Waves are faster but can only go through liquids.

• P-Waves are slower but can go through solids and liquids.

• S-Waves are faster and can go through solids and liquids.

• S-Waves are slower and can only go through solids.

Multiple Choice

How can we measure how far away an earthquake is from a seismograph?

• Measuring the height of the P-Waves.

• Measuring the height of the S-Waves.

• Measuring the distance between the P-Waves and S-Waves.

• Measuring the distance of the surface waves.

Multiple Choice

Which layer of the earth is in the liquid state of matter?

• Crust

• Mantle

• Outer Core

• Inner Core

Multiple Choice

How do we know that the outer core is liquid?

• P-Waves can't travel through them.

• S-Waves can't travel through them.

• P-Waves can travel through them.

• S-Waves can travel through them.