Oceans and Landforms Review

Which of the following causes weathering in rocks?

• freezing and thawing

• barometric presurre

• deposition

• sun and wind

Answer explanation

Cycles of freezing and thawing cause rocks to break apart. This is called weathering.

A volcano acts as a _______ process when its eruptions cause seamounts to form.

• magnetic

• constructive

• destructive

• gravitational

Answer explanation

A volcanic eruption can be either a constructive process or a destructive process.

When a volcanic eruption causes seamounts to form, the eruption is acting as a constructive process. However, when an eruption causes the top of the mountain to explode off, or it produces a lot of ash that damages forests, the eruption is destructive.

Jordan notices that the bottom part of a cliff is worn away.

Why is the cliff worn away the most near or under the level where the water is?

• because the moving water is what wears away the cliff

• because fish and animals who live in the water tear up the cliff

• because changes in temperature are greater in the water

• because the cliff is softer beneath the water line

Answer explanation

Water is what wears away the cliff in this example of erosion.

Lorraine is studying the effects of polluted rain. A common kind of polluted rain has acid in it. She has some samples of a kind of rock called limestone.

She runs pure water over one sample. She pours water with acid in it over the second sample. After a while, the second sample begins to break apart, but the first sample does not.

What does Lorraine's experiment show?

• the percolation rate of water through limestone

• how much more water than acid limestone can absorb

• what patterns water erosion can make in limestone

• that acid rain can dissolve limestone faster than regular rain

Answer explanation

Lorraine's experiment shows that acids can dissolve limestone faster than regular water can. This is important because acid rain can damage stone much faster than normal rain.

Wind gusts pick up loose sand from the ground and deposit it in a new location. As the sand piles up in its new location, it forms wavelike mounds.

What are these deposits called?

• beaches

• volcanoes

• sand dunes

• glaciers

Answer explanation

Sand dunes are often formed when wind picks up sand and deposits it in a new location. The wavelike mounds of sand are shaped by patterns of the flow of the wind.

What event caused the changes in the Earth's surface and destruction of homes in the pictures below?

• earthquakes

• tidal waves

• mudslides

• tornadoes

Answer explanation

The pictures are of mudslides. A mudslide occurs when rain fails to drain properly and causes rock and dirt to become unstable and to "slide" down a hill or mountain.

___________1__________ takes place when rocks are broken into smaller pieces and ___________2________ takes place when the small rock pieces are moved away.

• 1. weathering 2. erosion

• 1. erosion 2. weathering

• 1. deposition 2. erosion

• 1. weathering 2. deposition

Answer explanation

Weathering takes place when a rock is broken into smaller pieces. Erosion takes place when the small rock pieces are moved away.

What is the most significant difference between the way that erosion and a volcanic eruption change the surface of the Earth?

• A volcanic eruption comes from molten rock, but erosion only comes from water.

• A volcanic eruption affects a large area, but erosion only changes small areas at a time.

• A volcanic eruption carries land away, but erosion creates new land.

• A volcanic eruption creates new land, but erosion carries land away.

Answer explanation

A volcanic eruption builds up new land and is classified as a constructive force. Erosion carries land away through the movement of water, wind or ice, so it is classified as a destructive force.

Earthquakes are classified as _______ forces when they lift or fold the surface of the land to create new features.

• destructive

• deposition

• erosion

• constructive

Answer explanation

An earthquake acts as a constructive process when it builds up the surface of the Earth to create new landforms.

Destructive processes change the Earth's surface by removing material.

A natural event made the changes in the Earth's surface that caused the road shown in the picture to crack and break.

Which kind of event was it?

• earthquake

• wind

• floor

• snowstorm

Answer explanation

The road surface was most likely changed through the moving and shaking of part of Earth's crust. Earthquakes change the surface of Earth quickly when the rocks on both sides of a fault suddenly move.