4.7B Erosion

What type of changes does erosion cause?

• physical changes
• chemical changes
• electrical changes
• magnetic changes

Erosion occurs when natural forces alter the landscape. What does it mean to alter a landscape?

• to blow dust around
• to change what land looks like
• to deposit silt at the mouth of a river
• to create a floodplan

Which term best describes the rate at which glacial erosion takes place?

• quick
• slow
• sudden

How do sandy beaches form?

• Waves pounding pebbles into smaller and smaller pieces
• Wind eroding pebbles into smaller pieces
• Water freezing and thawing the cracks of pebbles
• Rain wearing away rocks into smaller and smaller pieces

How would a sandblasted rock differ from a rock that hasn't been sandblasted?

• A sandblasted rock would be bigger
• A sandblasted rock would be smoother in shape and less jagged
• A sandblasted rock would be composed of volcanic material
• A sandblasted rock would be covered by water

Why is it hard to see glacial erosion in action?

• Because glaciers are so big
• Because light from glaciers refracts too much
• Because glaciers move very, very slowly
• Because glacial erosion is usually very subtle

What do floodplains, sandbars, and river deltas have in common?

• They've all been formed by water erosion.
• They've all been formed by glacial erosion.
• They've all been formed by wind erosion.
• They've all been formed by sandblasting.

Based on the information presented in the movie, what would be a simple way to prevent erosion?

• Blocking the wind
• Planting trees
• Preventing rainfall
• Preventing the flow of rivers

Based on the information presented in the movie, what can you infer about the type of erosion that formed the Grand Canyon?

• Wind erosion
• Water erosion
• Sandblasting
• Glacial erosion

What is a good antonym for erosion?

• scattering
• rolling
• forming
• tumbling