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1 TO GO TO ANY OF THE PAGES LISTED BELOW, CLICK ON ITS TITLE CHAPTER 8 Erosion What are erosion and deposition? How does gravity cause erosion? How does running water cause erosion? What landforms does running water create? What causes caves, caverns, and sinkholes? 6 Contour Lines Enrichment Activity for Lesson 8-3 to What is a glacier? How do glaciers cause erosion? What landforms do glaciers create? How do ocean waves cause erosion? What landforms do ocean waves create? How does wind cause erosion? 13 Wave and Wind Erosion Enrichment Activity for Lessons 8-9 to THE BIG IDEA Integrating History: How did erosion change American history? 15 Chapter 8 Key Term Review 16 Chapter 8 Test 17 Chapter 8 Answer Key 20 (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 1

2 8-1 What are erosion and deposition? PART A Complete the following. Write your answers in the spaces provided. 1. What is erosion? 2. List five agents of erosion. 3. What is deposition? 4. Use the phrases building up and breaking down to explain how deposition differs from weathering. PART B Classify each of the following as an example of erosion or deposition. In the spaces provided, write E for erosion or D for deposition. 1. Pieces of broken shell are found along the shoreline after the tide goes out. 2. During a heavy rain, channels form in a muddy hillside. 3. Soil from an open field is blown into piles along a stone wall. 4. During a storm, sand is washed out from under a beachfront home. 5. Rocks at the top of a hillside begin to tumble down the hill. Skill: building vocabulary Use a dictionary to find the meaning of the terms erode and deposit. Write a definition for each term. Then, write a sentence that correctly uses each term without relating the term to Earth science. 1. erode: 2. deposit: (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 2

3 8-2 How does gravity cause erosion? Complete the following. Write your answers in the spaces provided. 1. What is mass erosion? 2. Name two examples of slow mass erosion. 3. Name two examples of rapid mass erosion. 4. What is gravity? 5. What is talus? 6. How is earthflow different from creep? 7. How does gravity differ from all other agents of erosion? 8. How can gravity cause movement of Earth materials? Skills: applying concepts, interpreting diagrams The map below shows some of the main rivers in the United States. Beside each river, draw an arrow to show the direction in which the river flows. Then, answer the questions that follow. 1. Toward what do rivers flow? 2. What force determines the direction in which direction a river will flow? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 3

4 8-3 How does running water cause erosion? PART A Place a check mark beside each form of running water. 1. a river 2. waves 3. rain 4. a stream 5. runoff 6. water in a pond PART B Complete the following. Write your answers in the spaces provided. 1. What is runoff? 2. What is a tributary? 3. Which can carry more soil a fast-moving river or a slow-moving river? 4. Which will erode faster a hill with a gentle slope or a hill with a steep slope? 5. Which will erode faster a hillside with many plants or a hillside with a few plants? Explain. Skills: labeling, map reading, analyzing Use the map of the Mississippi River system to complete the following. You may use an atlas or other reference materials for help. 1. Name three tributaries of the Mississippi River system. 2. What is the main stream of the Mississippi River system? 3. Name three states through which the Mississippi River flows. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 4

5 8-4 What landforms does running water create? Complete the following. Write your answers in the spaces provided. 1. Label the floodplain, mouth, and delta of the river shown. 2. Draw a triangle on the diagram around the delta of the river. 3. The place where a river ends is called its. 4. Soil and rock particles that settle to the bottom of a river are called. 5. What is the name for the flat area on the side of a river where sediments are deposited during floods? Skills: researching, building vocabulary, modeling Use the diagram to answer the questions. 1. What feature indicates that the diagram shows a well-developed floodplain? 2. What factors may have contributed to the development of the floodplain? 3. Why is the area within the floodplain smoother than the area outside the floodplain? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 5

6 8-5 What causes caves, caverns, and sinkholes? Complete the following. 1. What is topography? 2. Name three features of karst topography. 3. Where can karst topography be seen in the United States? 4. What causes karst topography? 5. What is formed when groundwater mixes with carbon dioxide from the air? 6. What is a cavern? 7. How does a sinkhole form? 8. What is a natural bridge? Skills: interpreting diagrams, sequencing In the space below each diagram, identify the feature of karst topography that is shown. Then, place the diagrams in the proper order to show the formation of a sinkhole lake. On the lines provided, explain how a sinkhole lake is formed The correct order of the diagram is. 5. Explanation: (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 6

7 Contour Lines Enrichment Activities for Lessons 8-3 to 8-5 Skills: map reading, analyzing The process of erosion affects the shape, or contour, of the land. An area s shape, or contour, can be determined by studying a topographic map. On a topographic map, points of equal elevation are connected by lines. These lines, called contour lines, are drawn at regular intervals. The amount of space between contour lines shows whether the surface of the land has a steep or gentle slope. Contour lines that are close together show land with a steep slope. Contour lines that are spread apart show land with a gentle slope. Short lines drawn at right angles on contour lines show places that have lower elevations than surrounding areas. The contour lines on the maps below have a contour interval of 10 m. This means that the difference in elevation between two contour lines is 10 m. Letters have been added to the maps to show specific locations. Use the maps to answer the questions that follow. 1. a. Which letter represents the location with the highest elevation? b. What is its elevation? 2. a. Which letter represents the location with the lowest elevation? b. What is its elevation? 3. Which location has an elevation greater than 60 m, but less than 70 m? 4. Which locations have an elevation of exactly 50 m? 5. Which map most likely represents a floodplain? Explain your answer. 6. Some places, such as caves and sinkholes, have lower elevations than surrounding areas. Infer how a sinkhole might be shown on a topographic map. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 7

8 8-6 What is a glacier? Match each term in Column B with its description in Column A. Write the letter of the correct term in the space provided. Column A 1. moving river of ice and snow 2. glacier that forms in mountains 3. glacier that forms near the poles 4. large piece of floating ice 5. period of very cold climatic conditions Column B a. iceberg b. glacier c. ice age d. valley glacier e. ice cap Label each diagram as a valley glacier, an ice cap, or an iceberg. Write your answer in the space provided (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 8

9 8-7 How do glaciers cause erosion? Circle the term that makes each statement true. 1. A moving river of ice and snow is (a glacier / an erratic). 2. As a glacier moves over bedrock, small pieces of the bedrock may be carved away by (erosion / abrasion). 3. As a glacier scrapes away the floor of a valley, the valley becomes (V-shaped / U-shaped). 4. Small valleys left high above a main valley are called (hanging / talus) valleys. 5. Rock and sediments that are left behind by a melting glacier are called (talus / till). 6. Large boulders that are left behind by a retreating glacier are called (till / erratics). 7. Till can best be described as (melted / loose) pieces of rock and sediment. Skills: analyzing, applying concepts Use the diagrams to answer the questions that follow. 1. Which valley was more likely to have been created by a glacier? 2. How does a glacier help to form a valley? 3. Is the formation of a valley by a glacier an example of erosion, abrasion, or both? Explain. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 9

10 8-8 What landforms do glaciers create? PART A Use the terms listed in the box to label the parts of the diagram shown below. Write your answers in the spaces provided. kettle lake U-shaped valley glacial lake drumlin moraine PART B Circle the term that makes each statement true. 1. When a glacier retreats, it deposits (till / talus). 2. The Great Lakes and New York's Finger Lakes are (glacial / kettle) lakes. 3. When till is deposited at the sides of a glacier, a (terminal / lateral) moraine is formed. 4. Oval-shaped mounds of till left by a retreating glacier are called (drumlins / moraines). 5. If a glacier moved south, the tip of a drumlin formed by the glacier would point (north / south). Skills: interpreting, identifying, applying concepts Study the drumlins. Then, use the compass to identify the direction of the glacier that formed as each drumlin was moving. Write the direction in the space provided (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 10

11 8-9 How do ocean waves cause erosion? Match each term in Column B with its description in Column A. Write the correct letter in the space provided. Column A 1. gap formed when waves cut completely through a section of rock 2. up-and-down movement of water 3. column of rock remaining after the collapse of a sea arch 4. flat section of rock formed by erosion of a sea cliff 5. steep rock face caused by wave erosion 6. hollowed-out part of a sea cliff Column B a. wave b. wave-cut terrace c. sea arch d. sea stack e. sea cliff f. sea cave Skills: identifying, sequencing Use the diagrams to complete the following. 1. Label each structure as one of the following: sea cave, sea cliff, sea arch, or sea stack. 2. Each of the structures shown forms from one of the others. Place the diagrams in the order in which they are most likely to have formed. 3. Which agent of erosion forms each of the structures shown? 4. What structure, not shown, is formed when the bottom of a sea cliff is worn away? Describe this structure. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 11

12 8-10 What landforms do ocean waves create? Complete the following. 1. Which agent of erosion creates beaches? 2. What kind of material forms white sand beaches? 3. What is a longshore current? 4. What kind of beach is formed by weathered volcanic rock? 5. What is a spit? 6. What is a sand bar? 7. How does a sand bar differ from a barrier beach? 8. Where is most of the sand that is carried from a beach deposited? Skills: interpreting, relating cause and effect The arrows in the flowchart below show wave movement. Read the description beside each arrow. Then, in the space with the same letter as each arrow, write the name of the feature each wave forms. Use the terms spit, beach, longshore current, barrier beach, and sand bar. a. d. b. e. c. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 12

13 8-11 How does wind cause erosion? PART A Label the windward side, the crest and the slipface of the sand dune shown below. Then, draw an arrow to show the direction that the wind is blowing. PART B Write true if the statement is true. If the statement is false, change the underlined term to make the statement true. Write your answers in the space provided. 1. The removal of loose materials from Earth's surface by the wind is called abrasion. 2. Wind carries silt and clay higher and farther than it carries sand. 3. Deposits of wind-blown dust are called talus. 4. The process by which rock and soil are worn away by particles carried by the wind is called deflation. 5. The windward side of a sand dune has a gentle slope. 6. Sand dunes are formed by deposition. Skills: applying concepts, interpreting a diagram Use the diagram to answer the questions that follow. 1. What process wore away the pole in the diagram? 2. Why can wind carry dust higher and farther than it can carry sand? 3. Was the pole more likely worn away by dust or sand? 4. Why is the pole worn away close to the ground? 5. Suggest two things that could have been done to prevent this pole from being worn away. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 13

14 Wave and Wind Erosion Enrichment Activity for Lessons 8-9 to 8-11 Skills: interpreting diagrams, designing an experiment, researching PART A Use the following terms to correctly label the diagram: sea stack, sea arch, and ocean waves. Write your answers in the spaces provided. a. b. c. PART B In the space below, design an experiment to test how sea arches and sea stacks form. Include a hypothesis and describe the procedure and materials you would use to conduct your experiment. Also, identify variables and safety precautions. PART C The force and the direction of the wind forms sand dunes with different shapes. Use reference materials to describe each kind of dune. 1. barchan: 2. parabolic: 3. transverse: 4. longitudinal: 5. star: (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 14

15 THE Big IDEA Chapter 8 How did erosion change American history? Integrating History Refer to the text, call outs, pictures, and map on pages 202 and 203 of your text to answer the following questions. 1. Which states were severely affected by the dust storms? 2. Which states were slightly affected by the dust storms? 3. Do you think Black Sunday is an appropriate nickname for April 14, 1935? Explain why. Skills: inferring, analyzing Complete the following. 1. Thousands of farmers left the Midwest during the 1930s and resettled in California. What are two reasons why they moved to this western state? 2. What are two reasons why a farmer might have chosen to stay in the Midwest rather than move to California? 3. Suppose you were a Midwestern farmer during the 1930s. Would you have moved to California or stayed on your farm? Explain why. Science Log Writing Activity Complete the Science Log on a separate sheet of paper. To complete the Big Idea Online, go to Follow the online instructions. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 15

16 Chapter 8 Key Term Review Use the clues to complete the crossword puzzle. Clues Across 1. stream that flows into the main stream of a river system 3. removal of loose material from Earth's surface 5. triangular deposit of sediment at the mouth of a river 6. soil and rock particles that settle in water 8. process by which material is carried by erosion and dropped in new places 9. series of connected underground caves 11. rock material deposited by a glacier 14. process by which weathered material is removed and carried from a place 16. boulder left behind by a retreating glacier 17. rainwater that flows into streams and rivers from surface areas Down 1. pile of rocks and rock particles that collects at the base of a slope 2. wearing away of rock particles by wind and water 4. large piece of a glacier that reaches the ocean 7. moving river of ice and snow 10. large hole in the ground formed when the roof of a cavern collapses 12. wind-blown dust 13. long, narrow deposit of sand connected at one end to a shoreline 15. long, offshore underwater deposit of sand parallel to a shoreline (2 words) (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 16

17 Chapter 8 Test Interpreting Diagrams Use the illustration to complete the following. mouth tributary source floodplain main stream delta 1. Use the list of terms to label the diagram on the lines provided. 2. What does the illustration show? 3. Where in the illustration would there be the most runoff? 4. Why are sediments deposited at the mouth of a river? Multiple Choice Write the letter of the term or phrase that best completes each statement in the space provided. 1. The process by which weathered materials are moved from one place to another is a. depositon. b. deflation. c. abrasion. d. erosion. 2. The agent of erosion that formed the Grand Canyon is a. running water. b. wind. c. gravity. d. waves. 3. Two examples of slow mass movement are a. landslides and creep. b. earthflow and creep. c. landslides and earthflow. d. creep and mudflows. 4. The removal of loose materials from Earth's surface by wind is a. deposition. b. deflation. c. abrasion. d. loess. 5. The side of a sand dune that has a steep slope is called the a. windward side. b. abrasion. c. slipface. d. moraine. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 17

18 Chapter 8 Test (continued) 6. Moraines and drumlins are two landforms created by a. gravity. b. wind. c. glaciers. d. running water. 7. A kettle lake is a landform created by a. wind. b. waves. c. running water. d. a glacier. 8. Most erosion begins with a. running water. b. wind. c. the force of gravity. d. glaciers. 9. The last ice age ended a. 1,000 years ago. b. 11,000 years ago. c. 110,000 years ago. d. 11 million years ago. 10. The place where a river ends is called its a. mouth. b. source. c. valley. d. floodplain. 11. Glaciers that form in mountains and move slowly downhill through valleys are called a. icecaps. b. continental glaciers. c. icebergs. d. valley glaciers. 12. The loose material deposited by a glacier is called a. talus. b. till. c. loess. d. spits. 13. When the top of a sea arch falls into the water, a a. sea stack forms. b. wave-cut terrace forms. c. sea cave forms. d. spit forms. 14. A long offshore underwater deposit of sand is called a a. longshore current. b. spit. c. barrier beach. d. sand bar. 15. Wind-blown dust is called a. till. b. talus. c. loess. d. a spit. 16. Sinkholes and caverns are features of a. wave erosion. b. karst topography. c. glacial topography. d. landslides. 17. Karst topography results from the action of groundwater on a. bedrock. b. quartz. c. feldspar. d. limestone. 18. A sinkhole lake forms when a sinkhole a. fills with water. b. contains carbonic acid. c. is located near the ocean. d. increases in size. 19. A long, narrow deposit of sand that is connected at one end to the shore is a a. sea stack. b. natural bridge. c. sand bar. d. spit. 20. Glaciers scrape out valleys that are a. very deep. b. filled with loess. c. V-shaped. d. U-shaped. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 18

19 Chapter 8 Test (continued) Written Response Answer the following questions in complete sentences. 21. INFER: Why might the floodplain of a river be a good location for a farm? Why might it be a poor location for a farm? 22. DESCRIBE: What causes a glacier to move? (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 19

20 Answer Key CHAPTER 8: EROSION 8-1 What are erosion and deposition? PART A 1. the process by which weathered material is removed and carried from a place 2. running water, wind, waves, glaciers, and gravity 3. the process by which material carried by erosion is dropped in new places 4. Answers should include the concept that during weathering, parts of Earth's surface are broken down, whereas deposition builds up parts of Earth's surface. PART B 1. D 2. E 3. D 4. E 5. E 1. To wear away or disintegrate; Students sentences will vary. 2. To place,or set, down; Students sentences will vary. 8-2 How does gravity cause erosion? 1. downhill movement of weathered materials caused by gravity 2. creep, earthflow 3. mudflows, landslides 4. a force that pulls all things on Earth toward Earth's center 5. pile of rocks and rock particles that collects at the base of a slope 6. Earthflow is the slow movement of soil and plant life down a slope. Creep is an even slower movement caused by gravity pulling soil and rocks down a gentle slope. 7. Gravity is a force, while the other agents of erosion are materials in motion. 8. The pull of gravity can cause objects to move from areas of higher elevation to areas of lower elevation. Check students drawings to make sure their arrows point toward the oceans. 1. oceans 2. gravity 8-3 How does running water cause erosion? PART A Students should place a check mark beside numbers 1, 4, and How does running water cause erosion? (continued) PART B 1. water from rain or snow that flows into streams and rivers from surface areas 2. smaller stream that flows into the main stream of a river system 3. a fast-moving river 4. a hill with a steep slope 5. a hillside with few plants; Plants slow erosion by holding soil particles together. 1. Accept any three of the following: Red River, Ohio River, Arkansas River, and Missouri River. 2. Mississippi River 3. Accept any three of the following: Minnesota, Wisconsin, Iowa, Illinois Missouri, Kentucky, Tennessee, Arkansas, Alabama, and Louisiana. 8-4 What landforms does running water create? 1. a. flood plain b. mouth c. delta 2. Check students' diagrams to make sure that they have included the entire delta. 3. mouth 4. sediment 5. flood plain 1. the flat low-lying areas on the sides of the river 2. Periods of heavy rain may have caused the river to overflow its sides and soil to be deposited on the sides. 3. Over time, running water and erosion shift the soil within the floodplain, creating a smooth area. The area outside the floodplain has not been as directly affected by running water and erosion. 8-5 What causes caves, caverns, and sinkholes? 1. the shape and look of the land 2. Accept any three of the following: bare, rocky land; caves; caverns; sinkholes; underground rivers; or natural bridges. 3. Florida and Kentucky 4. the action of groundwater on limestone 5. carbonic acid 6. a series of underground caves 7. when the roof of a cavern collapses 8. a structure formed when only part of a cavern roof collapses 1. sinkhole lake 2. sinkhole 3. cavern 4. C, B, A 5. A sinkhole lake is formed when a cavern roof collapses and the depression fills with water. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 20

21 Answer Key 8-5 What causes caves, caverns, and sinkholes? Enrichment Activity: Contour Lines 1 a. location F b. 100 m 2 a. location A b. 30 to 40 m 3. location E 4. locations D and G 5. Map 1; it shows a relatively flat area. 6. Answers will vary. Students may know that areas with lower elevations are shown on topographic maps by hachures, which are short lines drawn at right angles on contour lines. Hachures point in the direction of areas of lower elevation. 8-6 What is a glacier? 1. b 2. d 3. e 4. a 5. c 1. ice cap 2. valley glacier 3. iceberg 8-7 How do glaciers cause erosion? 1. a glacier 2. abrasion 3. U-shaped 4. hanging 5. till 6. erratics 7. loose 1. the valley in Figure A 2. As the glacier moves through the valley, it scrapes away pieces of the valley floor and carries these pieces to a new location. 3. both; The scraping away of the valley floor is an example of abrasion. The carrying away of valley sediments is an example of erosion. 8-8 What landforms do glaciers create? PART A 1. glacial lake 2. moraine 3. kettle lake 4. drumlin 5. U-shaped valley PART B 1. till 2. glacial 3. lateral 4. drumlins 5. south 1. west 2. northeast 3. southwest 4. south 8-9 How do ocean waves cause erosion? 1. c 2. a 3. d 4. b 5. e 6. f 1. A. sea stack B. sea cliff C. sea cave D. sea arch 2. B, C, D, A 3. waves 4. wave-cut terrace; flat section of rock that remains below the surface of the water 8-10 What landforms do ocean waves create? 1. waves 2. weathered quartz 3. movement of water parallel to the shoreline 4. black sand beach 5. a curved or hooked deposit of sand 6. a long, offshore underwater deposit of sand 7. A sand bar is a long, offshore underwater deposit of sand. A barrier beach is a sand bar that rises above the surface of the water. 8. offshore a. beach b. longshore current c. spit d. sand bar e. barrier beach 8-11 How does wind cause erosion? PART A a. crest b. slipface c. windward side; The wind is blowing from left to right. PART B 1. deflation 2. true 3. loess 4. abrasion 5. true 6. true 1. abrasion 2. Dust is lighter than sand. 3. sand 4. Sand is bounced along close to the ground. 5. Rocks could have been placed around the base of the pole to prevent the sand from wearing the pole away. Plants could have been planted around the base of the pole to form a windbreak. (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 21

22 Answer Key 8-11 How does wind cause erosion? Enrichment Activity: Wave and Wind Erosion PART A 1. sea stack 2. ocean waves 3. sea arch PART B Check students' experimental designs. PART C 1. crescent-shaped dune with open side away from the wind 2. crescent-shaped dune with open side facing into the wind 3. dune with long, wavelike patterns formed at right angles to wind direction 4. wavelike dune forming a ridge parallel to wind direction 5. dune with a high center point and arms of sand extending out from center The Big Idea 1. Colorado, Kansas, Oklahoma, Texas, and New Mexico 2. Montana, North Dakota, South Dakota, Wyoming, Nebraska, Iowa, Missouri, and Arkansas 3. Possible answer: The nickname is appropriate because it describes the color of the skies as severe dust storms struck the area. 1. mild climate and long growing season 2. Possible answers: farm is already established; unable to find a buyer for the land; connection to family and local community; Government agencies and programs were created to help the Midwestern farmers 3. Answers will vary. Students responses should incorporate reasons detailed in questions 1 and 2. CHAPTER 8: EROSION Chapter Test Interpreting Diagrams 1. a. tributary b. floodplain c. source d. main stream e. mouth f. delta 2. a river system 3. in the mountains 4. because the water slows down and slower-moving water cannot carry as much sediment Multiple Choice 1. d 2. a 3. b 4. b 5. c 6. c 7. d 8. c 9. b 10. a 11. d 12. b 13. a 14. d l5. c 16. b l7. d l8. a 19. d 20. d Written Response 21. Fertile soil that is deposited on a floodplain would make it good place to grow crops. Floods may damage crops. 22. Gravity and the weight of snow on top of the ice cause the ice to move forward. CHAPTER 8: EROSION Key Term Review PART A Across 1. tributary 3. deflation 5. delta 6. sediment 8. deposition 9. cavern 11. till 14. erosion 16. erratic 17. runoff Down 1. talus 2. abrasion 4. iceberg 7. glacier 10. sinkhole 12. loess 13. spit 15. sand bar (c) by Pearson Education, Inc./Globe Fearon/Pearson Learning Group. All rights reserved. Erosion: CHAPTER 8, page 22