Page 127 - Science Course 2 (Book 2)

Mo11-L1b: What Forces Change Earth’s Surface?

Force Changing Earth’s Surface Even though plates move slowly, the forces at plate
boundaries are strong enough to form huge moun-
Forces within Earth cause plates to move. tains and powerful earthquakes.

The three types of plate boundaries experience Tensional forces pull the land apart and form rift
different types of forces. valleys and mid-ocean ridges.

Compressional forces form mountains.

Convergent Transform Divergent

The squeezing force at a convergent boundary is
called compression.

The pulling force at a divergent boundary is called
tension.
The side-by-side dragging force at transform
boundaries is called shear. Key Concept

What Forces Change Earth’s Surface?

How do the forces created by plate motion change
Earth’s surface?

Unstressed
rock

Tension

SUMMARY
Compression Shear What Forces Change Earth’s Surface?

There are three types of tectonic plate
boundaries. Movement occurs at all three
boundaries.

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