FaultsBy: Angie and Katherine

About 250 million years ago, the continents of Earth were grouped together in one continent called “Pangea.”

It is just like the shell of an egg.

Earth’s crust

Land masses have moved and broken up and have reshaped the continents completely over millions of years ago.

It is like an egg shell that is cracked and put back together again.

It looks like the pieces of a jigsaw puzzle.

Tectonic Plates

Earth and an egg

The Earth’s tectonic plates and egg’s shell are very much alike.

Earth’s crust is broken into many tectonic plates.

There are big and small plates.

Earth’s tectonic plate map

The tectonic plates float around the mantle. Which causes the tectonic plates to move.

What causes tectonic plates to move?

The stress that is built up causes faults or cracks in Earth’s crust.

When one plate pushes against another, stress builds up. There are three kinds of stress. They are compression, tension, and shearing.

Plate and Shake!

Stress that pushes rock past one another.

A fault is a sudden break in the rocks that make up the Earth’s crust, also know as

tectonic plates.

What are Faults?

• Faults begin way below in the Earth. They start with a focus

point. Then every year or so, it will grow an inch or two. BIG

enough to be seen!

• Above the focus point is called an epicenter. The place is usually where most damage happens.

Do you know what it means ?

Cracks from faults create fault lines.

Some fault lines have split open the ground.

Large fault lines go deep underground and can stretch along a whole continent.

Many of earth’s major fault lines run along coastlines and across the ocean floor.

The world’s biggest fault lines are found near the edges of the Earth’s plate.

Fault Lines

San Andreas Fault

Faults develop deep underground in the Earth’s crust. A few can be seen on the surface. One of the most famous is California’s San Andreas fault.

There are three different types of major faults.

The Normal Fault The Strike-Slip Fault The Reverse Fault/Thrust Fault

What types of faults are there?

A normal fault is a section of the crust when it moves apart, rocks are stretched until they snap. When they snap it causes one block to move down along a sloping crack.

The Normal Fault

See? This is hanging here.

And this is hanging on top, like a foot on a big rock!

When rocks come together, they are compressed. One block moves along a sloping crack when the other block moves down.

The Reverse/Thrust Fault

Just like we said! They

compress lots of energy

together and one goes on

top one another!

footwall

Hanging wall

The strike-slip fault happens when rocks grind against each other, they move horizontally past each other in opposite directions. Just like two lanes of cars, and they go opposite sides!

The Strike-Slip Fault

Do they look the same to you?

Results of the faults

The hanging wall drops, tension is the stress.

Normal FaultStress that pulls rocks apart

The hanging wall moves up relative to the footwall.

Reverse faultCompression pushes rocks together

Strike-Slip faultStress that pushes rock past one another

The bed for planting slip apart. The fence was broken and offset 8 feet by the moving of a strike-slip fault.

Bibliography “Earthquakes.” [Online] Available http://www.studyblue.com, January 29, 2014. “Earthquakes and Seismology.” [Online] Available http://www.ucl.ac.uk/EarthSci/Earthquakes.htm,

January 28, 2014. “Earth’s tectonic plates.” [Online] Available http://www.windows2univers.org, January 26, 2014. “Faults.” [Online] Available http://www.smate.wwu.edu, January 29, 2014. Hawkins, John. Earthquake Disasters. New York: The Rosen

Publishing Group, Inc., 2012. “How do rocks deform?” [Online] Available http://www.geoscience.wisc.edu, September 26, 2013. Lynch, K. David. “San Andreas Fault.” [Online] Available http://www.SanAndreasFault.org, 2009.

Bibliography Morris, Neil. Earthquakes. New York: Crabtree Publishing

Company, 1998. OfficeManager. “Fault Lines in Texas.” [Online] Available

http://www.dawnsonfoundation.com/fault-lines-texas, September 5, 2013.

“Plate Tectonics.” [Online] Available http://www.geology.uprm.edu, January 25, 2014. “Reverse Faults” [online] Available

http://www.artinaid.com/components-and-types-of-geological-faults, April 2013.

Sipiera, P. Paul. Earthquakes. New York: Children’s Press, 1998.

Thoron, Joe. Earthquakes. Malayasia: Marshall Caverdish Corporation, 2007.

Walker, M. Sally. Earthquakes. Minneapolis: Carolrhoda Brooks, Inc., 1996.

Woods, Michael and, Woods, B. Mary. Earthquakes. Minneapolis: Learner Publications

Company, 2007.

We hope you’ve enjoyed the presentation!

Thank you for watching!