Lesson 3 | Changing Earth’s Surface

46 Earth’s Dynamic Surface

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Student Labs and Activities Page

Launch Lab 47

Content Vocabulary 48

Lesson Outline 49

MiniLab 51

Content Practice A 52

Content Practice B 53

School to Home 54

Key Concept Builders 55

Enrichment 59

Challenge 60

Lab A 63

Lab B 66

Lab C 69

Chapter Key Concepts Builder 70

Lesson 3 | Changing Earth’s Surface

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Earth’s Dynamic Surface 47

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How do rocks change? Weathering is any natural process that changes a rock. The processes can be physical or chemical. How can you tell the difference between physical and chemical weathering?

Procedure

Launch Lab LESSON 3: 15 minutes

Data and Observations

Think About This 1. When did physical weathering take place? When did chemical weathering take place?

Explain.

2. Key Concept What do you think is the difference between physical and chemical weathering?

1. Read and complete a lab safety form.

2. Use a graduated cylinder to pour 100 mL of water into a beaker. Use a wax pencil to mark this beaker with a W.

3. Pour 100 mL of vinegar into a second beaker. Mark this beaker with a V.

4. Break a piece of chalk into two equal pieces. Use a mortar and pestle to

crush one half. Put the crushed chalk on a piece of paper. Repeat for the other piece of chalk.

5. At the same time, add the crushed chalk to each beaker. In the Data and Observations section below, describe what happens.

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Changing Earth’s SurfaceDirections: On the line before each definition, write the letter of the term that matches it correctly.

Content Vocabulary

1. large mass of ice, formed by snow accumulation on land, that moves slowly across Earth’s surface

2. process of breaking down rock without changing the composition of the rock

3. triangular deposit of sediment that forms where stream enters a large body of water

4. mechanical and chemical processes that change Earth’s surface

5. process that changes the composition of rocks

6. series of actions or operations that lead to an end result

7. moving of weathered material, or sediment, from one location to another

8. material formed from rocks broken down by weathering

9. downhill movement of a large mass of rocks or soil due to gravity

10. laying down or settling of eroded material

A. chemical weathering

B. delta

C. deposition

D. erosion

E. glacier

F. mass wasting

G. physical weathering

H. processes

I. sediment

J. weathering

LESSON 3



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Changing Earth’s SurfaceA. Breaking Down Earth Materials

1. Processes that wear away and break down are often so slow that it is difficult to see changes in the mountains during a human’s lifetime.

a. The mechanical and chemical processes that change Earth’s surface over time are

referred to as .

b. The material formed from rocks broken down by weathering

is .

c. Sediment produced by weathering can be rock fragments, sand, silt,

or .

2. The process of breaking down rock without changing the composition of the rock is

called weathering.

a. Rocks can break as a result of motion or when a boulder rolls off a cliff.

b. seeping into cracks in rocks can freeze and shatter the rock.

c. The force from plant growing in cracks in rocks can pry the rock open.

3. The process that changes the composition of rocks is called

weathering.

a. Some minerals, such as calcite, can dissolve in slightly water, such as rainwater.

b. Other minerals react with carbon dioxide or oxygen in the

to form new .

c. Abundant water and higher temperatures speed up

weathering.

B. Moving Earth Materials

1. The term is used to describe the moving of weathered material, or sediment, from one location to another.

2. The laying down or settling of eroded material is .

Lesson Outline LESSON 3



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3. The downhill movement of a large mass of rocks or soil due to gravity is

called .

a. On tall mountains or steep slopes, the force of gravity can create a type of mass

wasting called a(n) .

b. The needed to move rocks and soil can come from

gravity, flowing water, wind, and moving .

4. Most erosion and of sediment is carried out by flowing water.

a. Faster water can carry larger pieces of than slower water.

b. When water slows, the sediment in the water is on the sides of the river.

c. When rivers enter oceans or lakes, sediment also is deposited, forming land

features called .

5. Erosion by can be the most important process that changes landforms in deserts.

6. Examples of landforms made by wind include dunes and ripples.

C. Ice

1. In cold climates, such as high mountains or near the poles, large masses of ice, formed by snow accumulation on land, that move slowly across Earth’s surface are

called .

a. The force of causes glaciers to flow and slide downhill, weathering the rocks over which the ice moves.

b. Glaciers can pick up and then deposit it when

they .

2. Plate tectonics explains many of surface features and the processes that occur on it.

3. , or the average weather in a region over a long period of time, affects the processes that move Earth material.

Lesson Outline continued



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How can wind change Earth’s surface?Wind changes Earth’s surface in different ways. How can you demonstrate how wind can change the land?

Procedur e

LESSON 3: 15 minutes

1. Read and complete a lab safety form.

2. Pour dry sand into a clear plastic box. Place two or three large pebblesand small clumps of grass on the surface of the sand.

3. Place the box into a cardboard boxthat is open on one side.

4. Plug in the hair dryer. Hold the hair dryer about 10 cm from the edge of the box at a 45° angle relative to the plastic box.

5. Turn the dryer on low. Hold it in the same position for 2–3 min. Record your observations in the Data and Observations section below.

Data and Observations

Analyze and Conclude 1. Observe How did the hair dryer—the wind model—change the sand? Be specific in your

answer.

2. Key Concept How does wind change Earth’s surface?

MiniLab



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Changing Earth’s SurfaceDirections: On each line, write the term from the word bank that correctly replaces the underlined words in each statement. Each term is used only once.

chemical weathering deposition erosion glacier

mass wasting physical weathering sediment weathering

1. The mechanical and chemical processes that change Earth’s surface over time can affect rocks in different ways.

2. The material formed from rocks broken down by weathering can be rock fragments, sand, silt, or clay.

3. The process of breaking down rock without changing the composition of the rock can occur when water repeatedly freezes and thaws in cracks in rocks.

4. The process that changes the composition of rocks can occur when minerals react with air and water to form new minerals.

5. The moving of weathered materials, or sediment, from one location to another changes the surface of Earth.

6. The laying down or settling of eroded material occurs when flowing water loses energy.

7. Landslides are a type of downhill movement of a large mass of rocks or soil due to gravity.

8. Gravity can cause a large mass of ice, formed by snow accumulation on land, that moves slowly across Earth’s surface to flow and slide downhill.

Content Practice A LESSON 3



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Changing Earth’s Surface Directions: Answer each question or respond to each statement in the space provided.

Question Answer

1. What does weathering do to rocks?

2. What is sediment?

3. Which kind of weathering does not change the composition of a rock?

4. Which kind of weathering changes the composition of a rock?

5. Compare erosion and deposition.

6. What is mass wasting?

7. Name four things that cause erosion and deposition.

8. Explain how a delta forms.

Content Practice B LESSON 3



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Changing Earth’s Surface Directions: Use your textbook to complete the graphic organizer below by adding descriptions for each item. Some boxes will require more than one description.

School to Home LESSON 3

Glaciers

Gravity

Wind

Water

Agents and Processes That Change Earth’s

Surface

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Changing Earth’s SurfaceKey Concept What is the difference between physical and chemical weathering?

Directions: Complete the concept map with the correct term or phrase from the word bank in the space provided. Each term or phrase is used only once.

breaks down rock without changing the composition physical weathering

changes the composition of rock rusting

Key Concept Builder LESSON 3

freezing and thawing

chemical weathering

Types of Weathering

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Changing Earth’s Surface Key Concept What is the difference between physical and chemical weathering?

Directions: On the line before each description, write P if the description is an example of physical weathering or C if the description is an example of chemical weathering.

1. Calcite in limestone dissolves in slightly acidic rainwater.

2. The roots of plants grow into the cracks in rocks.

3. A boulder rolls off a cliff and breaks apart.

4. Iron in rocks reacts with oxygen to form iron oxide.

5. Carbon dioxide reacts with feldspar to form clay.

6. Water seeps into cracks in rocks and freezes and thaws.

7. Faults rupture and cause rocks to break.

Directions: Answer each question or respond to each statement on the lines provided.

8. What is weathering?

9. Compare physical weathering and chemical weathering.

10. Give an example of a factor that can affect rates of weathering.




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Changing Earth’s SurfaceKey Concept How do water, ice, and wind change Earth’s surface?

Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided.

1. Landslides and other types of mass wasting are caused by gravity.

2. Most erosion and transport of sediment occurs by wind.

3. The slower water flows, the larger the pieces of sediment it can carry.

4. In deserts, erosion by water can be the most important process that changes

landforms.

5. Ripples are examples of landforms made by wind.

6. Glaciers typically form in cold climates, such as high mountains or near the

poles.

7. When a glacier freezes, it deposits the sediments that it carried.

8. Much of North America was covered by flowing water 20,000 years ago.

9. Climate, or the average weather in a region over a long period of time, can

affect the processes that change Earth’s surface.




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Changing Earth’s SurfaceKey Concept How do water, ice, and wind change Earth’s surface?

Directions: Complete the chart with the correct term from the word bank in the space provided. Some terms may be used more than once.

gravity ice water wind

Effect Cause

1. landslide

2. Grand Canyon

3. Niagara Falls

4. delta

5. sand dune

6. ripples

7. deep valleys and

Directions: Answer each question or respond to each statement on the lines provided.

8. How are plate tectonics related to Earth’s surface features?

9. Give an example of how climate can affect the processes that move Earth material.

10. Give an example of how plate movement can affect climate.




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Rocks and Time

Applying Critical-Thinking SkillsDirections: Respond to each statement.

1. Explain how we know that the rocks formed from the seafloor sediments deposited in the Amadeus Basin were softer than the arkose sandstone.

2. Analyze the following statement about the Grand Canyon: “The story that the rock layers tell is far older than the canyon itself.” Explain why you agree or disagree.

Ayers Rock in central Australia and the Grand Canyon in the western United States are two of many ancient rock formations that have been shaped over time by deposition, weathering, and erosion. They are special in the geologic sense for the stories that they tell about Earth’s history.

Uluru: Ayers RockAyers Rock is the most commonly used

name for the formation called “Uluru,” its aboriginal and official name. Uluru is located in the middle of Australia, surrounded by an empty plain. It is composed of arkose, a type of sandstone, and is the tip of a huge slab of rock that extends below the ground for possibly 5 to 6 km—no one really knows how far.

The presence of arkose sandstone in the formation is believed to be the result of the rapid erosion of granites from the ancestors of mountain ranges to the south. This arkose is one of many sedimentary formations filling the Amadeus Basin of Australia. Rainwater flowing down the mountains eroded sand and rock and dropped it in big fan shapes on the surrounding plain. Later, the whole area became covered by the sea. Sand and mud fell to the bottom and covered the seabed; then its weight turned both it and the fans into rock. Later, the sea disappeared and all of Central Australia was

subjected to massive forces that folded the layers and tilted the fan of hardened sand 90 degrees, so that the layers of sandstone almost stood on end. Over the last 300 million years, the softer rocks of the basin have eroded away, leaving the parts of the old fans exposed.

The Grand CanyonThe Grand Canyon is a steep-sided

gorge eroded by the Colorado River in the western United States. It is known for its overwhelming size and complex and colorful landscape. It is geologically significant because of the thick sequence of ancient rocks that are exposed in the walls of the canyon. These rock layers record much of the early geologic history of the North American continent. Many of the formations were deposited in shallow seas and swamps as the sea repeatedly advanced and retreated over the continent.

When later uplifts during mountain-building events moved the sediments thousands of feet upward, the stream gradient of the Colorado River was steepened and the river’s speed and ability to cut through rock was increased. Erosion is still shaping the canyon, and the different rock layers respond to it in different ways: some form slopes, some form cliffs, and some erode more quickly than others.

Enrichment LESSON 3

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Earth Processes at Uluru and the Grand CanyonOver time, the Earth processes of weathering, erosion, and deposition have shaped

the Uluru and Grand Canyon formations by acting in similar ways but producing different results.

Compare the Histories of Uluru and the Grand Canyon 1. Research photos of Uluru and the Grand Canyon and make copies or sketches of each

of the formations.

2. Using the images and research about their geologic histories, structures, and erosional dynamics, compare the history of the Earth processes that shaped each of the formations. Present your research in one of the following formats:

• an illustrated time line

• a photo or video journal

• a magazine article

• a TV field report

• a detailed diagram

• a 3-D model

3. Share your product with other groups in your class.

Challenge LESSON 3

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Earth’s Changing SurfaceYour teacher just opened a travel agency and has hired all of the students in your class as tour guides. Unlike a typical travel agency, Teacher’s Trusty Travel Tours offers tours to any part of the lower 48 states to explain how the region formed and continues to change. You will be a Trusty Travel Guide for one of these regions. As the expert, you will

• develop a travel slogan for your region;

• explain how the region formed and continues to change;

• make a travel brochure to persuade tourists that your region is the best place in the lower 48 states to visit.

Question Find out which region will be your tour-guide territory. What Earth processes do you think might have produced this region? How do you think Earth processes continue to change the region? What information about your region will be most interesting and persuade tourists to choose your area to visit?

Materialsglue stick

colored pencils

scissors

outline map of the United States

physiographic map of United States

Also needed: large paper 11 × 18

Safety

Procedure 1. A physiographic region is an area with certain relief, or elevation; specific rock types;

and specific geologic structures. You will work with an online, interactive physiographic map of the United States. Obtain the Web address for the map from your teacher.

2. Locate your region on the physiographic map.

Use a colored pencil to mark its location on the outline map of the lower 48 states. You may use the outline map in your travel brochure.

Lab A 2–3 class periods

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3. Research to find photographs of your region.

Study the photographs carefully, keeping in mind what you have learned in this chapter about the processes that change Earth’s surface.

Based on your observations, explain how you think your region formed.

4. Research your region and record your findings below. Use at least two references to obtain data about your region. Your data can include the geologic history of the region, landforms characteristic of the region, diagrams showing how the landforms formed, and any other information you find interesting.

5. Use the information you have gathered to make your travel brochure. Include the following:

• a map of your region,

• the region’s name,

• your travel slogan,

• two or more paragraphs describing the processes that formed and that continue to change the region, and

• several photographs and/or drawings of the region.

Lab Tips • Remember to rewrite any information you find in books or on the Internet in your

own words.

• When using the Internet, make sure the information is from a reliable source, such as a college or a university, an online encyclopedia, or a government agency.

• Your brochure must serve two purposes. It must be informative, yet easy to understand. It also must persuade people to visit that region of the country.

Lab A continued



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Analyze and Conclude 6. Research Information How did your research compare to how you thought your

region formed?

7. Classify the major Earth processes that produced your region as well as the processes that continue to change it.

8. The Big Idea How do the motion of tectonic plates and the processes of weathering, erosion, and deposition change Earth’s surface?

Communicate Your Results Use your travel brochure to put together a 1-minute speech about your region and why people should come to visit it. Practice your speech. Be prepared to answer any questions potential tourists might have!

Lab A continued

Remember to use scientific methods.

Ask a Question

Form a Hypothesis

Test your Hypothesis

Analyze and Conclude

Communicate Results

Make Observations



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Earth’s Changing SurfaceYour teacher just opened a travel agency and has hired all of the students in your class as tour guides. Unlike a typical travel agency, Teacher’s Trusty Travel Tours offers tours to any part of the lower 48 states to explain how the region formed and continues to change. You will be a Trusty Travel Guide for one of these regions. As the expert, you will

• develop a travel slogan for your region;

• explain how the region formed and continues to change;

• make a travel brochure to persuade tourists that your region is the best place in the lower 48 states to visit.

Question Find out which region will be your tour-guide territory. What Earth processes do you think might have produced this region? How do you think Earth processes continue to change the region? What information about your region will be most interesting and persuade tourists to choose your area to visit?

Materialsglue stick

colored pencils

scissors

outline map of the United States

physiographic map of United States

Also needed: large paper 11 × 18

Safety

Procedure 1. A physiographic region is an area with certain relief, or elevation; specific rock types;

and specific geologic structures. You will work with an online, interactive physiographic map of the United States. Obtain the Web address for the map from your teacher.

2. Locate your region on the physiographic map. Use a colored pencil to mark its location on the outline map of the lower 48 states. You may use the outline map in your travel brochure.

2–3 class periods Lab B



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3. Research to find photographs of your region. Study the photographs carefully, keeping in mind what you have learned in this chapter about the processes that change Earth’s surface. Based on your observations, explain how you think your region formed.

4. Research your region and record your findings below. Use at least two references to obtain data about your region. Your data can include the geologic history of the region, landforms characteristic of the region, diagrams showing how the landforms formed, and any other information you find interesting.

5. Use the information you have gathered to make your travel brochure. Include a map of your region, the region’s name, your travel slogan, two or more paragraphs describing the processes that formed and that continue to change the region, and several photographs and/or drawings of the region.

Lab Tips • Remember to rewrite any information you find in books or on the Internet in your

own words.

• When using the Internet, make sure the information is from a reliable source, such as a college or a university, an online encyclopedia, or a government agency.

• Your brochure must serve two purposes. It must be informative, yet easy to understand. It also must persuade people to visit that region of the country.

Lab B continued



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Analyze and Conclude 6. Research Information How did your research compare to how you thought your region

formed?

7. Classify the major Earth processes that produced your region as well as the processes that continue to change it.

8. The Big Idea How do the motion of tectonic plates and the processes of weathering, erosion, and deposition change Earth’s surface?

Communicate Your ResultsUse your travel brochure to put together a 1-minute speech about your region and why people should come to visit it. Practice your speech. Be prepared to answer any questions potential tourists might have!

Find the tour guides for two other regions that are close to yours. Talk about any similarities and differences among the regions and how they formed.

Extension

Lab B continued

Remember to use scientific methods.

Ask a Question

Form a Hypothesis

Test your Hypothesis

Analyze and Conclude

Communicate Results

Make Observations



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Model Changes in Your RegionDirections: Use the information and data from the Lab Earth’s Changing Surface to perform this lab.

You have learned that Earth’s surface can change due to factors such as earthquakes and erosion. In Lab B, you created a travel brochure using information about the landforms of a specific region of the United States. Now make a model to show how your region has changed over time and/or how it continues to change. For example, you could model the effects of an earthquake or of forces that cause erosion, such as water or wind. Develop a hypothesis about your model and then test your hypothesis.

Please note that you must complete Lab B before beginning Lab C. Also, have your teacher approve your design and safety procedures before beginning your experiment.

Lab C



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Earth’s Dynamic SurfaceEnd-of-Chapter PracticeDirections: Work with a group to recommend solutions to problems caused by erosion.

Research how erosion affects your area. Find answers to the following questions:

What types of erosion affect your area? Which local or state agencies have information about erosion?

Gather and then analyze your data. Address questions such as the following:

How does erosion affect local landforms? How does erosion affect the local economy?

Research and recommend solutions to problems caused by erosion in your area.

What action is already being taken to address the problem?

What resources are needed to implement your recommended solutions?

Are your recommendations feasible to implement?

Compare your recommendations with those of other groups. As a class, decide which solutions are best. Consider sending your recommendations to a local official for feedback.

Recommendation requirements:• includes research about local problems caused by erosion

• includes visuals and references

• is organized in a logical manner

• includes contributions from each group member

Chapter Key Concepts Builder

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Lesson 3 | Changing Earth’s Surface

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Lesson 3 | Changing Earth’s Surface