Geo Unit II: Forces that Shape the Earth

Unit II: Forces that Change the Earth

Mr. Tolle

Change to the Earth

⬥Internal Forces

changes to the surface as a result of plate tectonics.

Maps and Charts 2

⬥ Plate movement can be:

1. Convergent (colliding)
Subduction:
plates colliding
with each other.
Ex. Himalayan Mountains

1. Convergent (Colliding) /Subduction:

a. Crust folds= mountains
b. Crust subducts = trenches, coastal mountains,

volcanoes

⬥ Plate movement can be:

2. Divergent/Spreading:

plates pulling away
from each other.
As they pull apart,
a deep gap called
a rift valley forms.
Ex. Rift Valley
of Africa, Iceland

​National Geographic:
Plate Tectonics (Vimeo)

Divergent/Spreading:

Iceland is in the middle
of a divergent boundary.
Iceland is the only
place on Earth
where you can see
an ocean spreading
center on land. (North
American Plate and Eurasian Plate)

North

American

Plate

Eurasian
Plate

Thingvellir, Iceland

Multiple Choice

What is the national park in Iceland where you can touch the North American plate and the Eurasian plate?

• Yellowstone National Park
• Banff National Park
• Thingvellir National Park
• Yosemite National Park

Multiple Choice

The Great Rift Valley was created by what type of tectonic plate boundary?

• Convergent (colliding) plate boundaries

• Divergent (spreading) plate boundaries

• Transform plate boundaries
• Plateau formation

Multiple Choice

Naturally occurring features on the surface of the planet are called

• Landmarks

• Landforms

• Tourist Attractions

• Farmland

Drag and Drop

Mountains are created by ​

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tectonic plates.

Trenches, the Great Rift Valley in Africa, and Iceland were created by ​

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plates

Drag these tiles and drop them in the correct blank above

colliding

spreading

transform

⬥ Plate movement can be:

3. Transform Plate Movement

sliding alongside each
other. Ex. San Andreas
Fault in California

⬥ Some internal forces create:

1. Earthquakes: sudden release of pressure between plates

⬥ Some internal forces create:

2. Faulting: break in rock layers causes
significant
upward
movement
on one
side of
fault.

Drag and Drop

​

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plate movement creates faults, such as the San Andreas Fault in ​

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.

Drag these tiles and drop them in the correct blank above

Transform

California

Mexico

Colliding

Spreading

⬥ Some internal forces cause
3. Folding: rock layer bends, but does not break / fault

⬥ External Forces --

1. Weathering ("The Hammer")

   1. Chemical

   2. Physical

2. Erosion ("The Bulldozer")

   1. Wind

   2. Water

   3. Gravity

   4. Glaciers

Landforms

⬥ Features on the surface of the planet created by internal and external forces.

1. Mountains – ex. Rocky Mountains

2. Hills – ex. Black Hills
3. Plains – ex. Great Plains and

4. Plateaus – Ozark Plateaus

Hamm Plateau, Ethiopia

Half Moon Bay

Gulf of Mexico

Caspian Sea, Central Asia (East of Azerbaijan)

Water Features

1. Streams – Bodies of water flowing over the land. This includes rivers, creeks, brooks, etc.

2. Wetlands – This includes swamps, bayous, bogs.

3. Groundwater – Some of the Earth’s freshwater is underground.

The source for most groundwater is
from rain filtering through the soil.

4. Lakes. Can be fresh or salt!

Wetlands

Water Cycle

⬥ Regular movement of water from ocean to atmosphere to ground to .... ocean!

– Evaporation (off leaves = Transpiration)
– Condensation
– Precipitation