Seismic Waves Lesson

Seismic Waves Lesson Day 2

Today we will go over some important things you will need to know about earthquakes and seismic waves.

Multiple Choice

This is known as the sudden shaking of the ground and known as the sources of seismic waves.

• earthquake

• tsunami

• flood

• typhoon

Multiple Choice

What scale is used to measure an earthquake?

• Ricther Scale

• A big scale

• Seismic Scale

Multiple Choice

This is the name of the single digit number that means how powerful an earthquake is. It is measured on the Richter scale

• Force

• Stress

• Magnitude

• Plate Boundary

Earthquakes

• In El Centro, California, in 1979, a farm area experienced shaking ground. The picture below shows a farm field in the area shortly after this happened

• Discuss: What happened?

• Large pieces of Earth's crust moved, which produced seismic waves.

• The first type of wave in an earthquake is a primary wave

Multiple Choice

Which type of wave arrives first during an earthquake?

• Primary (p-wave) waves

• Secondary (s-wave) waves

• Rayleigh Waves

• Love Waves

Multiple Choice

Earthquakes happen when two large pieces of Earth's crust suddenly slip or break. Which of these could be caused by an earthquake?

• building damage

• tsunami

• landslide

• all of these

There are many different types of seismic waves

There are body waves and surface waves

P Waves= Primary waves

The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth. It pushes and pulls the rock it moves through just like sound waves push and pull the air. 

S Waves=Secondary Waves

The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave and can only move through solid rock, not through any liquid medium.

Multiple Choice

Which best models a P wave moving through Earth's crust?

Multiple Choice

This question has two parts. First, answer Part 1. Then, answer Part 2.

Part 1 from "Seismic Waves"

Which type of seismic wave was most likely recorded at the station?

• P Wave

• S Wave

Multiple Choice

Part 2

from "Seismic Waves"

Which best explains the correct answer to Part 1?

• It travels slower than the other types of seismic waves.

• It is the seismic wave that can travel through all of Earth's layers.

• It causes particles to travel in a circular motion around all of Earth.

There are 2 types of surface waves

Love and Rayleigh

Love Wave

The first kind of surface wave is called a Love wave, named after A.E.H. Love, a British mathematician who worked out the mathematical model for this kind of wave in 1911. It's the fastest surface wave and moves the ground from side-to-side.

Rayleigh Waves

The other kind of surface wave is the Rayleigh wave, named for John William Strutt, Lord Rayleigh, who mathematically predicted the existence of this kind of wave in 1885. A Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean.

Rayleigh Wave

Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.

Multiple Choice

Which best models an S wave moving through Earth's crust?

Multiple Choice

The point where the earthquake begins.

• epicenter

• fault

• focus

• seismic waves

Reminder:

The spot underground where the rock breaks is called the focus of the earthquake.

The place right above the focus (on top of the ground) is called the epicenter of the earthquake.

Faults are cracks in the earth where sections of a plate (or two plates) are moving in different directions.

Multiple Choice

What part of the earth is broken in to 12 major tectonic plates?

• Crust

• Mantle

• Inner Core

• Outer Core

Multiple Choice

When plates break or slip past each other they form these

• mountains

• tectonic plates

• Fault lines

• earthquakes

Multiple Choice

This is the area above ground where the earthquake starts

• focus

• epicenter

• p waves

• plate boundary

Thank you!

Now that we have reviewed this material you will need to go take the Seismic Waves Quizizz for a grade! Good luck. It is due today.

Stay in the Google Meet!

When you are done stay in the Meet with me until you have completed any unfinished science assignments. You can turn your volume down while you work, but come back to the Meet to get permission to leave. I will dismiss everyone at 2:25.