Glencoe Science
Chapter Resources
Erosional
Forces
Includes:
Reproducible Student Pages
ASSESSMENT
TRANSPARENCY ACTIVITIES
✔ Chapter Tests
✔ Section Focus Transparency Activities
✔ Chapter Review
✔ Teaching Transparency Activity
HANDS-ON ACTIVITIES
✔ Assessment Transparency Activity
✔ Lab Worksheets for each Student Edition Activity
Teacher Support and Planning
✔ Laboratory Activities
✔ Content Outline for Teaching
✔ Foldables–Reading and Study Skills activity sheet
✔ Spanish Resources
✔ Teacher Guide and Answers
MEETING INDIVIDUAL NEEDS
✔ Directed Reading for Content Mastery
✔ Directed Reading for Content Mastery in Spanish
✔ Reinforcement
✔ Enrichment
✔ Note-taking Worksheets
Glencoe Science
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Table of Contents
To the Teacher
Reproducible Student Pages
■
iv
Hands-On Activities
MiniLAB: Modeling Slump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
MiniLAB: Try At Home Observing How Soil Is Held in Place . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Lab: Glacial Grooving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Lab: Design Your Own Blowing in the Wind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Laboratory Activity 1: Mass Movements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Laboratory Activity 2: Modeling a Glacier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Foldables: Reading and Study Skills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
■
Meeting Individual Needs
Extension and Intervention
Directed Reading for Content Mastery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Directed Reading for Content Mastery in Spanish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Enrichment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Note-taking Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
■
Assessment
Chapter Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Chapter Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
■
Transparency Activities
Section Focus Transparency Activities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Teaching Transparency Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Assessment Transparency Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Teacher Support and Planning
Content Outline for Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T2
Spanish Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T5
Teacher Guide and Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T9
Additional Assessment Resources available with Glencoe Science:
•
•
•
•
•
•
•
•
•
ExamView® Pro Testmaker
Assessment Transparencies
Performance Assessment in the Science Classroom
Standardized Test Practice Booklet
MindJogger Videoquizzes
Vocabulary PuzzleMaker at msscience.com
Interactive Chalkboard
The Glencoe Science Web site at: msscience.com
An interactive version of this textbook along with assessment resources are available
online at: mhln.com
iii
To the Teacher
This chapter-based booklet contains all of the resource materials to help you teach
this chapter more effectively. Within you will find:
Reproducible pages for
■ Student Assessment
■ Hands-on Activities
■ Meeting Individual Needs (Extension and Intervention)
■ Transparency Activities
A teacher support and planning section including
■ Content Outline of the chapter
■ Spanish Resources
■ Answers and teacher notes for the worksheets
Hands-On Activities
Laboratory Activities: These activities do not require elaborate supplies or extensive pre-lab
preparations. These student-oriented labs are designed to explore science through a stimulating yet simple and relaxed approach to each topic. Helpful comments, suggestions, and
answers to all questions are provided in the Teacher Guide and Answers section.
Foldables: At the beginning of each chapter there is a Foldables: Reading & Study Skills
activity written by renowned educator, Dinah Zike, that provides students with a tool that
they can make themselves to organize some of the information in the chapter. Students may
make an organizational study fold, a cause and effect study fold, or a compare and contrast
study fold, to name a few. The accompanying Foldables worksheet found in this resource
booklet provides an additional resource to help students demonstrate their grasp of the
concepts. The worksheet may contain titles, subtitles, text, or graphics students need to
complete the study fold.
Meeting Individual Needs (Extension and Intervention)
Directed Reading for Content Mastery: These worksheets are designed to provide students
with learning difficulties with an aid to learning and understanding the vocabulary and
major concepts of each chapter. The Content Mastery worksheets contain a variety of formats
to engage students as they master the basics of the chapter. Answers are provided in the
Teacher Guide and Answers section.
iv
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
MiniLAB and Lab Worksheets: Each of these worksheets is an expanded version of each lab
and MiniLAB found in the Student Edition. The materials lists, procedures, and questions
are repeated so that students do not need their texts open during the lab. Write-on rules are
included for any questions. Tables/charts/graphs are often included for students to record
their observations. Additional lab preparation information is provided in the Teacher Guide
and Answers section.
Directed Reading for Content Mastery (in Spanish): A Spanish version of the Directed
Reading for Content Mastery is provided for those Spanish-speaking students who are
learning English.
Reinforcement: These worksheets provide an additional resource for reviewing the concepts of the chapter. There is one worksheet for each section, or lesson, of the chapter.
The Reinforcement worksheets are designed to focus primarily on science content and less
on vocabulary, although knowledge of the section vocabulary supports understanding of
the content. The worksheets are designed for the full range of students; however, they will
be more challenging for your lower-ability students. Answers are provided in the Teacher
Guide and Answers section.
Enrichment: These worksheets are directed toward above-average students and allow them
to explore further the information and concepts introduced in the section. A variety of
formats are used for these worksheets: readings to analyze; problems to solve; diagrams
to examine and analyze; or a simple activity or lab which students can complete in the
classroom or at home. Answers are provided in the Teacher Guide and Answers section.
Note-taking Worksheet: The Note-taking Worksheet mirrors the content contained in the
teacher version—Content Outline for Teaching. They can be used to allow students to take
notes during class, as an additional review of the material in the chapter, or as study notes
for students who have been absent.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Assessment
Chapter Review: These worksheets prepare students for the chapter test. The
Chapter Review worksheets cover all major vocabulary, concepts, and objectives
of the chapter. The first part is a vocabulary review and the second part is a concept review.
Answers and objective correlations are provided in the Teacher Guide and Answers section.
Chapter Test: The Chapter Test requires students to use process skills and understand content.
Although all questions involve memory to some degree, you will find that your students will
need to discover relationships among facts and concepts in some questions, and to use higher
levels of critical thinking to apply concepts in other questions. Each chapter test normally
consists of four parts: Testing Concepts measures recall and recognition of vocabulary and
facts in the chapter; Understanding Concepts requires interpreting information and more
comprehension than recognition and recall—students will interpret basic information and
demonstrate their ability to determine relationships among facts, generalizations, definitions,
and skills; Applying Concepts calls for the highest level of comprehension and inference;
Writing Skills requires students to define or describe concepts in multiple sentence answers.
Answers and objective correlations are provided in the Teacher Guide and Answers section.
Transparency Activities
Section Focus Transparencies: These transparencies are designed to generate interest
and focus students’ attention on the topics presented in the sections and/or to assess
prior knowledge. There is a transparency for each section, or lesson, in the Student Edition.
The reproducible student masters are located in the Transparency Activities section. The
teacher material, located in the Teacher Guide and Answers section, includes Transparency
Teaching Tips, a Content Background section, and Answers for each transparency.
v
Teaching Transparencies: These transparencies relate to major concepts that will benefit
from an extra visual learning aid. Most of these transparencies contain diagrams/photos
from the Student Edition. There is one Teaching Transparency for each chapter. The Teaching
Transparency Activity includes a black-and-white reproducible master of the transparency
accompanied by a student worksheet that reviews the concept shown in the transparency.
These masters are found in the Transparency Activities section. The teacher material includes
Transparency Teaching Tips, a Reteaching Suggestion, Extensions, and Answers to Student
Worksheet. This teacher material is located in the Teacher Guide and Answers section.
Assessment Transparencies: An Assessment Transparency extends the chapter content and
gives students the opportunity to practice interpreting and analyzing data presented in
charts, graphs, and tables. Test-taking tips that help prepare students for success on standardized tests and answers to questions on the transparencies are provided in the Teacher
Guide and Answers section.
Teacher Support and Planning
Content Outline for Teaching: These pages provide a synopsis of the chapter by section,
including suggested discussion questions. Also included are the terms that fill in the blanks
in the students’ Note-taking Worksheets.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Spanish Resources: A Spanish version of the following chapter features are included in this
section: objectives, vocabulary words and definitions, a chapter purpose, the chapter Activities, and content overviews for each section of the chapter.
vi
Reproducible
Student Pages
Reproducible Student Pages
■
Hands-On Activities
MiniLAB: Modeling Slump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
MiniLAB: Try At Home Observing How Soil Is Held in Place . . . . . . . 4
Lab: Glacial Grooving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Lab: Design Your Own Blowing in the Wind . . . . . . . . . . . . . . . . . . . . 7
Laboratory Activity 1: Mass Movements . . . . . . . . . . . . . . . . . . . . . . . 9
Laboratory Activity 2: Modeling a Glacier . . . . . . . . . . . . . . . . . . . . . 11
Foldables: Reading and Study Skills. . . . . . . . . . . . . . . . . . . . . . . . . . 13
■
Meeting Individual Needs
Extension and Intervention
Directed Reading for Content Mastery . . . . . . . . . . . . . . . . . . . . . . . 15
Directed Reading for Content Mastery in Spanish . . . . . . . . . . . . . . 19
Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Enrichment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Note-taking Worksheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
■
Assessment
Chapter Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Chapter Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
■
Transparency Activities
Section Focus Transparency Activities . . . . . . . . . . . . . . . . . . . . . . . . 40
Teaching Transparency Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Assessment Transparency Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Erosional Forces
1
Hands-On Activities
Hands-On
Activities
2 Erosional Forces
Date
Class
Hands-On Activities
Name
Modeling Slump
Procedure
WARNING: Do not pour lab materials down the drain.
1. Place one end of a baking pan on two bricks and position the other end
over a sink with a sealed drain.
2. Fill the bottom half of the pan with gelatin powder and the top half of the
pan with aquarium gravel. Place a large, flat rock on the gravel.
3. Using a watering can, sprinkle water on the materials in the pan for several
minutes. Record your observations.
Data and Observations
Analysis
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
1. What happened to the different sediments in the pan?
2. Explain how your experiment models slump.
Erosional Forces
3
Name
Date
Class
Procedure
1. Obtain a piece of sod (a chunk of soil about 5 cm thick with grass growing
from it).
2. Carefully remove the soil from the sod roots by hand. Examine the roots
with a magnifying lens.
3. Wash hands thoroughly with soap and water.
Analysis
1. Draw several of these roots in the space below.
2. What characteristics of grass roots help hold soil in place and thus reduce erosion?
4 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Hands-On Activities
Observing How Soil Is Held in Place
Name
Date
Class
Hands-On Activities
Glacial Grooving
Lab Preview
Directions: Answer these questions before you begin the Lab.
1. Why is the safety symbol for thermal safety shown for this lab?
2. Would you expect the glacier channel to have a different shape than the meltwater channel?
Why or why not?
Throughout the world’s mountainous regions, 200,000 valley glaciers are
moving in response to gravity.
Real-World Question
How is the land affected when a valley glacier
moves downslope?
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Materials
sand
large plastic or metal tray *stream table
ice block
books (2 or 3)
*wood block
metric ruler
overhead light source with reflector
*Alternate materials
Goals
■
Compare stream and glacial valleys.
3. Position the overhead light source to shine
on the channel as shown.
4. Force the ice block into the channel at the
upper end of the tray.
5. Gently push the ice along the channel until
it’s halfway between the top and bottom of
the tray, and directly under the light.
6. Turn on the light and allow the ice to melt.
Record what happens.
7. Record the width and depth of the ice
channel in the table. Make a scale drawing.
Figure 1
Safety Precautions
WARNING: Do not pour sand down the drain.
Make sure source is plugged into a GFI electrical
outlet. Do not touch light source—it may be hot.
Procedure
1. Set up the large tray of sand as shown
above. Place books under one end of the
tray to make it slope.
2. Cut a narrow channel, like a river, through
the sand. Measure and record its width and
depth. Draw a sketch that includes these
measurements on the next page.
Erosional Forces
5
Name
Date
Class
(continued)
Glacier Data
Width
Depth
Observations
Original channel
Glacier channel
Meltwater channel
Directions: Use the space below to sketch your channel. Be sure to include the channel’s measurements.
Conclude and Apply
1. Explain how you can determine the direction that a glacier traveled from the location of deposits.
2. Explain how you can determine the direction of glacial movement from sediments deposited
by meltwater.
3. Describe how valley glaciers affect the surface over which they move.
6 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Hands-On Activities
Data and Observations
Name
Date
Class
Design Your Own
Hands-On Activities
Blowing in the Wind
Lab Preview
Directions: Answer these questions before you begin the Lab
1. Why is it important to wear safety goggles during this lab?
2. Would you expect increased speeds of wind to increase the amount of erosion? Why or why not?
Have you ever played a sport outside and suddenly had the wind blow dust
into your eyes? What did you do? Turn your back? Cover your eyes? How
does wind pick up sediment? Why does wind pick up some sediments and
leave others on the ground?
Real-World Question
Safety Precautions
What factors affect wind erosion?
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Form a Hypothesis
How does moisture in sediment affect the
ability of wind to erode sediments? Does the
speed of the wind limit the size of sediments it
can transport? Form a hypothesis about how
sediment moisture affects wind erosion. Form
another hypothesis about how wind speed
affects the size of the sediment the wind can
transport.
Goals
■
■
Observe the effects of soil moisture and
wind speed on wind erosion.
Design and carry out experiments that test
the effects of soil moisture and wind speed
on wind erosion.
Possible Materials
flat pans (4)
fine sand (400 mL)
gravel (400 mL)
hair dryer
sprinkling can
water
28-cm ✕ 35cm cardboard sheets (4)
tape
mixing bowl
metric ruler
wind speed indicator
Wear your safety goggles at all times when
using the hair dryer on sediments. Make
sure the dryer is plugged into a GFI electrical
outlet.
Test Your Hypothesis
Make a Plan
1. As a group, agree upon and write your
hypothesis statements.
2. List the steps needed to test your first
hypothesis. Plan specific steps and vary only
one factor at a time. Then, list the steps
needed to test your second hypothesis. Test
only one factor at a time.
3. Mix the sediments in the pans. Plan how you
will fold cardboard sheets and attach them
to the pans to keep sediments contained.
4. Design data tables to record your data in
the Data and Observations section.
5 Identify all constants, variables, and controls of the experiment. One example of a
control is a pan of sediment not subjected
to any wind.
Erosional Forces
7
Name
Date
Class
(continued)
1. Make sure your teacher approves your plan before you start.
2. Carry out the experiments as planned.
3. While doing the experiments, write any observations that you or other members of your group
make. Summarize your data in the data tables.
Data and Observations
Analyze Your Data
1. Compare your results with those of other groups. Explain what might have caused any
differences among the groups.
2. Explain the relationship that exists between the speed of the wind and the size of the sediments
it transports.
Conclude and Apply
1. How does energy of motion of the wind influence sediment transport? What is the general
relationship between wind speed and erosion?
2. Explain the relationship between the sediment moisture and the amount of sediment moved
by the wind.
Communicating Your Data
Design a table that summarizes the results of your experiment, and use it to explain your
interpretations to others in the class.
8 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Hands-On Activities
Follow Your Plan
Date
1
Laboratory
Activity
Class
Mass Movements
The force of gravity causes loose material to move down slope. Sometimes water helps to move
the material. Water makes the material heavier and more slippery.
Down slope movements of earth materials may be sudden or slow. Landslides and mudflows
are sudden movements. Rocky slopes tend to move as landslides; clay and sand materials may
become mudflows.
Creep is an example of slow earth movement. Even when a slope is covered by vegetation, the
soil may creep to a lower level.
Strategy
You will cause mass movements.
You will classify the mass movements.
Figure 1
Materials
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
stream table with hose
4 wood blocks
plastic bucket
protractor
1 L clay
1 L sand
sprinkling can
water
1 L gravel
meterstick
Procedure
1. Set up the stream table as shown in Figure 1.
2. Place the protractor with its flat edge down
on the table that is supporting the stream
table. Position the protractor next to the
lower end of the stream table. Use the protractor to measure the slope angle of the
stream table. Record the angle in Table 1.
3. Place the clay in the upper end of the
stream table.
4. Pour the sand over the clay. Wet the sand
and clay thoroughly until it moves.
5. Observe and record in Table 1 how the
mass moves.
6. Add two more blocks under the stream
table. Measure and record the new slope
angle of the stream table.
7. Move the sand and clay back to the upper
end of the stream table.
8. Pour water over the sand and clay until it
moves. Record how the mass moves.
9. Remove the sand and clay. Spread a thin
layer of clay in the upper end of the table.
10. Spread gravel over the clay. Pour water
over the clay and gravel and observe the
motion. Record your observations.
Erosional Forces
9
Hands-On Activities
Name
Name
Date
Class
Laboratory Activity 1 (continued)
Table 1
Material
Slope angle (°)
Speed of movement
Sand, clay
Sand, clay
Clay, gravel
Questions and Conclusions
1. What type of mass movement did you cause in steps 3 and 4?
2. What type of mass movement did you cause in steps 7 and 8?
3. What caused the difference in speed between these two mass movements?
4. What type of mass movement did you cause in steps 9 and 10?
5. Which type of mass movement would occur during an extended period of heavy rain on a
filled area? Explain.
6. Which type of mass movement, creep or mudflow, is most destructive? Explain.
7. In an area that receives abundant rainfall, how are steep slopes kept from moving downhill?
Strategy Check
Can you cause mass movements?
Can you classify mass movements?
10 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Hands-On Activities
Data and Observations
Name
Date
Modeling a Glacier
Hands-On Activities
2
Laboratory
Activity
Class
Valley glaciers start in the mountains where snow collects and remains year
after year. When the amount of snow accumulation exceeds the amount of
snow melting and the snow mass is thick enough, gravity starts the glacier
moving downslope. The glacier can take over a river valley as it moves toward
a lower elevation. The glacier gouges and scrapes the surface beneath the ice
and changes the landscape in many ways.
Strategy
You will construct a model of a valley glacier.
You will show the rugged features a valley glacier forms as it moves and melts.
Materials
cardboard base (21.5 cm ✕ 28 cm)
4 colors of modeling clay
paper for labels
tape (clear)
toothpicks
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Procedure
1. On the cardboard base, form a mountain
from the darkest piece of clay.
2. Use white clay to show the position of a
glacier on your mountain.
3. Show the erosional features of the glacier. Use
the toothpicks and paper to make little flags.
4. You might wish to use a thin layer of green
clay to show where vegetation has begun
to appear.
5. Be sure to model each of the following
features: U-shaped valley, cirque, terminal
moraine, horn, and outwash plain.
6. Draw a diagram of your model under Data
and Observations on the next page. Label
the features.
Questions and Conclusions
Write a summary explaining how valley glaciers form and move and how they change the landscape.
Erosional Forces
11
Name
Date
Class
Laboratory Activity 2 (continued)
Draw glacier diagram here.
Strategy Check
Can you construct a model of a valley glacier?
Can you correctly model and label the features left by a valley glacier?
12 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Hands-On Activities
Data and Observations
Name
Date
Class
Hands-On Activities
Erosional Forces
Directions: Use this page to label your Foldable at the beginning of the chapter.
Erosion
Deposition
Gravity
Glaciers
Wind
Plucking results in rock
fragments that can leave
grooves and striations.
Sediments are deposited as
the mass movement loses energy.
This type of erosion is also
called mass movement.
This type of erosion works by
slowly moving sediment that is
trapped in solid ice.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
As ice melts, sediment is
deposited on the land.
Deposits can form moving
dunes, barchan dunes or
transverse dunes.
Deposits include till, moraine,
outwash, and eskers.
Deposits of fine sediment
are called loess.
Erodes by deflation
or abrasion.
Erosion can form a cirque,
an arête, or a horn.
Examples include sandstorms
and dust storms.
Examples include slump,
creep, rock slides, and mudflows.
Erosional Forces
13
Meeting Individual Needs
Meeting Individual
Needs
14 Erosional Forces
Name
Date
Directed Reading for
Content Mastery
Class
Overview
Erosional Forces
Directions: Use the following terms to complete the concept map below.
deflation
wind
gravity
creep
slump
glaciers
plucking
outwash deposits
mudflow
Meeting Individual Needs
Erosional forces
are
1.
5.
8.
water
which causes
which cause
2.
6.
which causes
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
abrasion
and
and
and
rockfalls
and
rockslides
7.
9.
and
and
3.
till
deposits
and
4.
Erosional Forces
15
Name
Date
Directed Reading for
Content Mastery
Section 1
Section 2
■
■
Class
Erosion by Gravity
Glaciers
Directions: Use the words and phrases below to complete the cause and effect chart.
rock slides
creep occurs
plants removed from hilly areas
increased erosion
mudflows
Cause
glacier melts and retreats
rocks carried by glaciers
Effect
1.
heavy rain builds up in dry sediment
2.
3.
bedrock left with scrapes and grooves
4.
outwash is left behind
freezing and thawing make soil slide
slowly downhill
5.
6.
7.
Directions: Correctly complete each sentence by underlining the best of the two choices in parentheses .
8. Agents of erosion drop sediments they are carrying when their energy
(increases, decreases).
9. Mass movements are caused by (gravity, glaciers).
10. Tilted walls and fences are a sign (mudflow, creep) is occurring.
11. Striations and (till, grooves) are marks on rocks that indicate the
direction a glacier moved.
12. (Continental, Valley) glaciers covered up to 28 percent of Earth before retreating
to the poles.
13. Valleys eroded by (glaciers, streams) are U-shaped.
14. (Hundreds, Thousands) of years ago, huge ice sheets covered portions of the
northern United States.
15. Till deposited at the end of a glacier when it stops moving forward is called a(n)
(esker, moraine).
16 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Meeting Individual Needs
large rocks break loose from a slope
Name
Date
Directed Reading for
Content Mastery
Class
Section 3 Wind
■
Directions: Use the following terms to complete the sentences below.
root
storm
sandstorm
deflation
facing
barchan
dunes
abrasion
windbreaks
away
vegetation
materials
loess
place to place.
2. During ___________________, wind moves lighter particles of sand, clay, and
silt and leaves heavier materials behind.
3. During __________________, wind-blown particles scrape away the surfaces of
rocks.
4. When soil dries out, high winds can erode it and form a dust
__________________.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
5. Lines of trees called __________________ can decrease soil erosion.
6. Grasses have fibrous __________________ systems that hold soil in place.
7. Fine deposits from wind that blew across glacial outwash areas are known as
__________________.
8. ___________________ can form when wind blows sediment against an obstacle.
9. In a sand dune, the side __________________ the wind is less steep.
10. Dunes move __________________ from the direction of the wind.
11. A dune shaped like a crescent is called a ___________________ dune.
12. A low cloud of windblown grains of sands is called a ___________________ .
13. People in many countries plant ___________________ to reduce wind erosion.
Erosional Forces
17
Meeting Individual Needs
1. Moving air can pick up loose ___________________ and move them from
Name
Date
Directed Reading for
Content Mastery
Class
Key Terms
Erosional Forces
Directions: Match each term in Column I with its definition in Column II. Write the letter of the definition on the
lines provided.
1. erosion
2. deposition
Meeting Individual Needs
3. creep
4. moraine
5. glacier
Column II
a. wearing away surface materials and moving
them to another location.
b. glacial deposits that can completely fill valleys
c. fine-grained sediments deposited by the wind
d. ice and snow moving under its own weight
6. abrasion
e. process of dropping sediments when the energy
of motion decreases
7. slump
f. sediments slowly inch down a hill
8. loess
g. process of wind-blown sediments scratching
and scraping rock
9. plucking
10. till
h. process of wind removing small particles
11. deflation
i. glacial deposit that looks like it’s been pushed
into place by a bulldozer
12. mass movement
13. outwash
14. dune
j. a mass movement that occurs when materials
slip down a curved slope
k. boulders, gravel, and sand being added to the
bottom of a glacier
l. a mound of sediments drifted by the wind
m. erosion that happens as gravity moves materials
downslope
n. material deposited by the meltwater from a glacier
18 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Column I
Nombre
Fecha
Lectura dirigida para
Dominio del contenido
Clase
Sinopsis
Fuerzas erosivas
Instrucciones: Usa los términos para completar el mapa conceptual.
deflación
viento
corrientes de lodo
desprendimiento
corrimiento
ablación
depósitos derrubiados
glaciares
gravedad
Satisface las necesidades individuales
Las fuerzas
erosivas
son
1.
5.
8.
agua
que causan
que causan
2.
6.
que causan
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
abrasión
y
y
y
derrumbes y
derrubios de rocas
7.
9.
y
y
3.
depósitos
de tilita
y
4.
Fuerzas erosivas
19
Nombre
Fecha
Lectura dirigida para
Dominio del contenido
Clase
Sección 1
■
Sección 2
■
Erosión causada
por la gravedad
Los glaciares
Instrucciones: Usa las palabras y frases para completar la tabla de causas y efectos.
derrubios de rocas se elimina vegetación de áreas empinadas glaciares se derriten y retroceden
ocurre el corrimiento aumenta la erosión corrientes de lodo los glaciares llevan rocas
Causa
Efecto
1.
lluvias torrenciales se acumulan en sedimentos secos
2.
3.
lecho de rocas con raspaduras
y acanaladuras
4.
deja atrás los derrubios
la congelación y descongelación hacen que
el suelo se deslice lentamente cuesta abajo
5.
6.
7.
Instrucciones: Completa correctamente cada oración subrayando la mejor opción.
8. Los agentes de la erosión descargan los sedimentos que llevan cuando
(aumentan/disminuyen) su energía.
9. (La gravedad/Los glaciares) causan los movimientos de masas.
10. Las paredes y muros inclinados son una señal de que está ocurriendo
(una corriente de lodo/corrimiento).
11. Las estriaciones y (tilitas/acanaladuras) son marcas en las rocas que indican la
dirección en que se ha movido un glaciar.
12. Los glaciares (continentales/de valle) cubrían casi el 28 por ciento de la Tierra
antes de retroceder hacia los polos.
13. Los valles erosionados por (glaciares/corrientes) tienen forma de U.
14. Hace (cientos/miles) de años grandes capas de hielo cubrían partes del norte de
Estados Unidos.
15. La tilita que se deposita al final de un glaciar cuando deja de avanzar se llama
(ésker/morrena).
20 Fuerzas erosivas
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Satisface las necesidades individuales
rocas grandes se desprenden de una pendiente
Nombre
Fecha
Lectura dirigida para
Clase
Sección 3 El viento
■
Dominio del contenido
Instrucciones: Usa los siguientes términos para completar las oraciones.
abrasión
cortavientos
de espaldas a
vegetación
materiales
loes
1. El aire en movimiento puede levantar ___________________ sueltos y llevarlos
de un sitio a otro.
2. Durante un(a) __________________ , el viento se lleva las partículas más
livianas de arena, arcilla y limo y deja atrás las partículas más pesadas.
3. Durante un(a) __________________, las partículas que lleva el viento raspan la
superficie de las rocas.
4. Cuando el suelo se reseca, los vientos fuertes pueden erosionarlo y formar
__________________ de polvo.
5. Las filas de árboles llamadas __________________ pueden ayudar a disminuir
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
la erosión del suelo.
6. Las pastos tienen sistemas de __________________, que retienen el suelo en su
sitio.
7. Los depósitos finos del viento que sopló sobre las áreas de derrubios glaciales se
conocen como __________________.
8. Los(Las) ___________________ se pueden formar cuando el viento sopla los
sedimentos contra un obstáculo.
9. En una duna de arena, el lado que está __________________ al viento es
menos inclinado.
10. Las dunas se mueven __________________ la dirección del viento.
11. Una duna que tiene forma de media luna se llama ________________ .
12. Una nube baja formada por granos de arena llevados por el viento se llama
___________________.
13. Las gentes de muchos países siembran ___________________ para reducir la
erosión causada por el viento.
Fuerzas erosivas
21
Satisface las necesidades individuales
raíz
deflación
de cara a
tormenta
barján
tormenta de arena
dunas
Nombre
Fecha
Lectura dirigida para
Dominio del contenido
Clase
Términos claves
Fuerzas erosivas
Instrucciones: Aparea cada término de la Columna I con su definición en la Columna II. Escribe la letra de la
definición en las líneas de la izquierda.
Columna II
1. erosión
2. depositación
Satisface las necesidades individuales
3. corrimiento
4. morrena
a. desgaste de los materiales de la superficie y su
transporte a otro sitio
b. depósitos glaciares que pueden llenar valles
completamente
5. glaciar
c. sedimentos de grano fino depositados por el
viento
6. abrasión
d. hielo y nieve moviéndose por sí mismos
7. desprendimiento
e. proceso de descargar los sedimentos cuando
disminuye la energía de movimiento
8. loes
9. ablación
10. tilita
11. deflación
12. movimientos de
masa
13. derrubios
14. duna
f. los sedimentos se mueven lentamente colina
abajo
g. proceso mediante el cual los sedimentos que
lleva el viento raspan y pulen las rocas
h. proceso mediante el cual el viento se lleva las
partículas pequeñas
i. depósitos glaciares que parecen haber sido
empujados por una niveladora
j. movimiento de masas que ocurre cuando los
materiales se deslizan por una pendiente curva
k. rocas, grava y arena que se agregan al fondo de
un glaciar
l. pila de sedimentos que fueron transportados
por el viento
m.cualquier tipo de erosión que ocurre cuando la
gravedad se lleva los materiales cuesta abajo
n. material depositado por el agua que se derrite de
un glaciar
22 Fuerzas erosivas
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Columna I
Name
1
Date
Reinforcement
Class
Erosion by Gravity
Directions: Complete the items on the lines provided.
1. Identify the types of mass movement described below.
b. These are common in mountainous areas. A sign that these have
occurred is a pile of rocks at the bottom of a hill. They occur most
often after heavy rains or during earthquakes.
c. These are likely to happen in relatively dry areas with thick layers of
dry sediment. They occur after heavy rains fall. Sediments and water
mix together to form a thick mixture that slides.
d. It causes sediments to slowly move downhill. It happens in areas
where the ground freezes and thaws. As the ground freezes,
expanding water in the soil pushes up sediments. When the ground
thaws, the sediments fall downslope. This is a slow process.
2. What do the above four types of erosion have in common?
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
3. Identify the types of mass movement from the clues provided.
a. Leaning fenceposts
b. A curved scar where eroded material once was located
c. A fan-shaped deposit
d. “Beware of falling rock” signs
Directions: Answer the following questions in complete sentences.
4. Hawaii consists of a chain of tropical islands. Would you expect to see evidence of creep there?
Explain.
5. In a usually dry area, homes were built into a hillside on thick layers of clay and dirt. Late one
summer, a long drought was followed by heavy rain. What kind of mass movement might the
area experience? Explain.
Erosional Forces
23
Meeting Individual Needs
a. This happens when underlying material is weakened and can no
longer support material on top of it. Loose material slips downward
as a large mass.
Name
2
Date
Reinforcement
Class
Glaciers
Directions: Answer the following questions on the lines provided.
1. How are continental glaciers and valley glaciers similar?
Directions: Use your answers above to identify the glaciers described below. You may need to use both types to
answer a question.
3. They form U-shaped valleys.
4. They covered much of Earth during ice ages.
5. They deposit till and outwash.
6. They weather rocks by plucking.
7. They form in areas that have cold temperatures all year.
8. They are now located only in the polar regions.
9. They are the kind of glaciers found in Montana today.
10. They can create cirques on the side of mountains.
24 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Meeting Individual Needs
2. How are continental glaciers and valley glaciers different?
Name
3
Date
Reinforcement
Class
Wind
Directions: Complete the following sentences using the correct terms.
1. Wind erosion called __________________ pits and polishes rocks when blown sand grains
hit them.
2. ___________________ are a common form of wind deposit in desert regions and near
oceans and lakes.
3. Much of the midwestern United States is on fertile soil that developed from
Meeting Individual Needs
____________________ deposits.
4. ______________________ is sediment that is as fine as talcum powder.
5. Erosion and ____________________ are part of a cycle that shapes and reshapes the land.
6. ____________________ is wind erosion that can be compared to sandblasting.
7. When windblown sediments pile up behind obstacles, ___________________ are formed.
8. Abrasion and deflation are forms of ___________________ erosion.
9. Loess and dunes are ___________________ of wind-eroded sediments.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
10. ___________________ is wind erosion that picks up small particles and leaves heavier
particles behind.
11. The side of a sand dune away from the wind has a _________________ slope than the side
facing the wind.
12. ____________________ erosion is common in deserts, beaches, and plowed fields.
13. During a __________________, sand grains form a low cloud just above the ground.
14. _________________ blow topsoil from open fields, overgrazed areas, and places where
vegetation has disappeared.
15. People in many countries plant trees to act as _________________ to reduce wind erosion.
16. Along many seacoasts and deserts, _________________ is planted to reduce erosion.
17. Plants with fibrous _________________ systems, such as grasses, work best at stopping wind
erosion.
18. One common dune shape is a crescent-shaped dune known as a _________________.
Erosional Forces
25
Name
Enrichment
Class
Landslide!
Meeting Individual Needs
Landslides can occur as a result of an act
of nature or can be triggered by human
activities. An act of nature might be an
earthquake or heavy rains. Human activities
include road building or the construction of
homes on or near an unstable slope. What
makes a slope unstable? There are a number
of factors that make a slope unstable, including
increased erosion, increased water, decreased
vegetation and root systems, earthquakes, and
the addition of a load, such as a building, to the
slope. Landslides are most likely to happen where
there are steep slopes combined with a triggering
event. In the United States alone, landslides kill
an average of 25 people a year and cause about
$2 billion in damages and loss. They occur in all
50 states but are especially prominent in the
Appalachian region, New England, mountainous
areas of the West, and California.
Severe Landslide in California
In California during the winters of 1997
and 1998, severe rainstorms attributed to
El Niño caused numerous damaging landslides. In January 1997 Highway 50 between
Sacramento and Lake Tahoe closed as tons of
earth poured down a Sierra Nevada canyon
slope, burying the highway. Clearing the road
took more than a month. Around 35,000
truckloads of mud and debris had to be
removed costing the state $4.5 million.
Because this is an active area for landslides,
the U.S. Geological Survey (USGS) installed
monitoring devices to keep track of landslide
triggers such as rainfall, ground movement
and vibration, and groundwater pressure. The
following winter and spring, landslides in the
San Francisco area caused such heavy loss and
damage that President Clinton declared ten
counties disaster areas.
This region has a history of devastating landslides, including landslides in 1982 that killed
25 people and caused extensive destruction of
buildings and property.
A Landslide Kills Thousands
While these landslides were mainly water
induced, human factors can also cause landslides. One of the most tragic examples of
this was a human-induced landslide that
claimed thousands of lives and caused a large
amount of property damage. It’s known as the
Vaiont Dam Disaster of 1963. The Vaiont Dam
was a 266-meter-tall, concrete structure built in
a high valley in the Italian Alps in 1960. Three
years after the completion of the dam, heavy
rains, a full reservoir, and weak layers of clay in
the ground spelled disaster for nearby residents. The resulting landslide was 2 km long,
1.5 km wide, and several hundred meters thick.
The landslide charged down the mountain into
the dam’s reservoir, sending a 100-meter-high
wave of water over the top of the dam. The
water raced down the valley and crashed into
the town of Longarone, destroying the town
and killing 3,000 people. This tragedy brought
to the forefront the need for structural engineers to understand geology, slope, and the
nature of landslides.
Reducing Damage and Loss
In the United States the National Landslide
Hazards Program (NLHP) recognizes that
landslides are a major geologic hazard. The
organization does research, gathers information, writes reports, and responds to disasters.
The program’s goals are to reduce damages
and loss from landslides by improving understanding of ground-failure causes and suggesting preventive and relief strategies.
Directions: Use library resources to find a specific example of a destructive landslide. Identify its location,
causes, degree and type of damage, and date of incidence. Write a paragraph of your findings on a separate
sheet of paper. Be sure to identify your sources of information.
26 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
1
Date
Name
2
Date
Enrichment
Class
Beware of Ice!
Many terms are used to describe glaciers, their movement, and their erosive and depositing
impact. Use dictionaries, encyclopedias, and library books to define or describe the following
glacier-related terms.
1. Basal sliding
Meeting Individual Needs
2 Plastic flow
3 Rock flour
4. Kettles
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
5. Calving
6. Ice sheets
7. Drumlins
8. Zone of accumulation
9. Zone of ablation
Erosional Forces
27
Name
Enrichment
Class
Beach Renourishment
Meeting Individual Needs
When you hear the word erosion, what do
you think of? Most people probably think of
farm land that’s being worn away by water
or wind. However, beaches also experience
erosion. Beach erosion has many causes, both
natural and human. Natural causes include
currents, tectonic plate movement, earthquakes, waves, tides, and winds. Human causes
of beach erosion are over-development of land
and construction of harbors and jetties for
pleasure boating. The things that make living at
the beach so nice can have a devastating effect
on the beach itself. That’s because they interfere
with the natural movement of sand. As part of
the natural process, sand moves up and down a
beach in a drifting pattern. Unfortunately, jetties and other structures interrupt that process,
and the sand is deposited in one area and not
further down the beach. Because less sand is
being carried by water, erosion takes place.
A Beach Disappears and Reappears
One severe example of beach erosion was in a
coastal area of western Florida where an entire
beach almost disappeared. Before the erosion,
the beach was about 24 m wide and served as a
protective barrier for the oceanfront properties
that lined the beach.
Two decades later, the beach was barely 3 m
wide. When beaches erode, lives and property
are placed at risk. Fortunately, the beach underwent renourishment, a process that puts
beaches back the way they were before erosion
changes them. The renourishment effort
restored 46 m of beach per day until a new and
enlarged beach measuring 41–56 m was created.
Rebuilding a Beach
Renourishing a beach is very different from
how it’s created in nature. A beach is naturally
created over time when waves and tides bring
sand and broken down seashells to the shoreline. With renourishment, however, creating a
beach involves tugboats, barges, bulldozers,
and other heavy equipment. Sand from
another location (where it’s plentiful) is
loaded onto a barge that is towed by a tugboat to a pumping station. The sand-filled
barge is connected to a water-filled pipe, and
the sand and water mixture is blasted onto
the surface of the beach. Finally, bulldozers
come along and evenly spread the mountains
of sand until a beautiful new beach is created.
This beach renourishment process has been
used on more than 161 km of Great Lakes
and coastal beaches.
1. List at least three causes of beach erosion. For each, indicate whether the cause is natural or
human.
2. Why is the beach so important to the people who live along it?
3. The western Florida beach renourishment project cost $22.8 million. Do you think it was
worth the price tag? Give reasons to support your answer.
28 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
3
Date
Name
Date
Note-taking
Worksheet
Section 1
Class
Erosional Forces
Erosion by Gravity
A. ________________—wearing away and moving of surface materials by gravity, water, wind,
or glaciers
B. Through the process of ___________________, sediments are dropped by erosion agents as
C. ______________________ occurs as gravity moves materials down a slope as one large mass.
1. ______________—material slips down a curved surface as one large mass.
2. Sediments slowly shift downhill in the process of ______________.
3. __________________ and rock slides occur when rocks break off or slip suddenly down
a hill.
4. A ________________ is a thick mixture of water and sediments flowing downhill.
D. Consequences of _____________________—buildings on slopes eventually have problems
due to erosion by gravity.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
1. Sometimes builders and residents make slopes more unstable by making
them ___________________.
2. Another source of instability is the removal of ___________________.
E. Steep slopes can be made safer with vegetation, _________________ pipes, and walls of
concrete or railroad ties.
Section 2
Glaciers
A. ________________—large mass of ice and snow slowly moving on land; an agent of erosion
B. As glaciers move, they pick up boulders, gravel, and sand in an erosion process
called _________________.
1. Plucked rocks at the base of the glacier ______________ the soil and bedrock.
2. Dragged rock fragments leave scars on bedrock called ______________.
3. ___________________ are shallower scars on bedrock.
4. Grooves and striations indicate the __________________ a glacier moved.
Erosional Forces
29
Meeting Individual Needs
they lose energy.
Name
Date
Class
Note-taking Worksheet (continued)
C. As glaciers retreat, they leave behind _____________, a mixture of different sized sediments.
1. Till areas include wide swaths of _____________ from Iowa to Montana, and Ohio to Illinois.
2. A ________________ is a ridge, or pile, of deposit left at the end of a glacier.
3. ________________—material deposited in layers by the meltwater of a glacier, with largest
pieces closer to the glacier
4. An_______________ is a type of outwash deposit formed as meltwater rivers within the ice
deposit sand and gravel within their channels.
percent of Earth in areas near the poles, as much as 28 percent of Earth was covered by glaciers
1. Periods of widespread glaciation over the last 2 million to 3 million years are known
as _________________.
2. The average air temperature on Earth was about ____________ lower during ice ages than
today.
3. The last major ice age was about _______________ years ago.
E. _______________ glaciers—exist in mountains
1. ________________ are bowl-shaped basins in the sides of mountains, created by valley
glaciers.
2. A long ridge or ______________ forms when two valley glaciers erode a mountain
side-by-side.
3. A _____________ forms when valley glaciers erode a mountain from several directions.
4. Glacially eroded valleys have a __________ shape, as opposed to the V shape left by stream
erosion.
F. Glaciers have changed, and continue to change, the shape of Earth’s surface; sand and
gravel deposits left by glaciers are important resources for the construction
of ____________________________.
30 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Meeting Individual Needs
D. ____________________ glaciers—huge masses of ice and snow now covering only about 10
Name
Date
Class
Note-taking Worksheet (continued)
Section 3
Wind
A. _____________________—can scatter dust or volcanic ash over thousands of kilometers
1. __________________—wind removes small particles of loose sediment, leaving behind
heavier materials.
2. Wind behaves like a sandblaster blowing sand grains against rocks wearing them down and
pitting them in the process of _________________.
Meeting Individual Needs
3. Deflation and abrasion happen most often in areas where there is little
___________________ to hold sediments in place.
4. When strong winds blow in the deserts, beaches, or dry riverbeds, an airborne sand cloud
or __________________ occurs.
5. ____________________ occur when winds blow dry topsoil from open fields, overgrazed
areas, or places with little or no vegetation.
B. Reducing wind erosion—plant ___________________
1. ___________________—rows of trees can slow down wind reducing erosion; they also
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
trap snow to increase moisture.
2. ______________—fibrous root system plants such as grasses help anchor soil particles.
C. ______________________ by wind—airborne particles eventually return to Earth.
1. Fine-grained sediments known as ______________ helped form fertile soils in the
Midwestern United States.
2. A mound of sediments drifted by the wind is called a _____________.
a. Dunes _____________ as the wind continues to blow against them.
b. The more gently sloping side of a dune faces the _____________.
c. Dunes have different ____________, such as crescents, lines, or stars, based on
sediments, wind speed and direction, and vegetation.
D. Erosion and deposition are constantly _________________ the shape of the land.
Erosional Forces
31
Assessment
Assessment
32 Erosional Forces
Name
Date
Chapter
Review
Class
Erosional Forces
Part A. Vocabulary Review
Directions: In the blank at the left, write the letter of the term or phrase that best completes each statement.
1. All of the following are mass movements except ______.
a. valley glaciers
b. creep
c. rockslides
d. mudflows
2. The process that wears away surface materials and moves them from one location to
another is ______.
c. abrasion
d. deposition
a. mass movement b. erosion
3. When wind blows sediment against an obstacle, the buildup of sediment results in
the formation of ______.
a. a dune
b. till
c. an esker
d. loess
4. A moving mass of snow and ice is a ______.
a. moraine
b. loess
c. till
d. glacier
5. The gouging of bedrock by rock fragments dragged by glaciers results in ______.
a. striations
b. abrasion
c. meltwater
d. valleys
7. The dropping of sediments by any agent of erosion is called ______.
a. cirque
b. outwash
c. deposition
d. deflation
8. Leaning poles are one indication of a kind of mass movement called ______.
a. erosion
b. slump
c. creep
d. deposition
9. A ______ is a mass movement that occurs when underlying material is weakened and
can no longer support material on top of it.
a. till
b. slump
c. mudslide
d. rill
10. When particles of fine windblown sediment settle out of the air and become packed,
the resulting deposit is called ______.
a. loess
b. till
c. dunes
d. outwash
11. When a glacier stops moving forward, a(n) ______ may be deposited in front of it.
a. outwash
b. dune
c. moraine
d. slump
12. The boulders, sand, clay, and silt that drop from a glacier when it retreats are
called ______.
a. loess
b. till
c. dunes
d. slump
13. One way people increase erosion is by ______.
a. installing drains b. removing plants c. planting grass
d. building walls
14. ______ is the process by which a glacier loosens and moves rocks.
a. Creep
b. Outwash
c. Erosion
d. Plucking
Erosional Forces
33
Assessment
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
6. Till and outwash are both deposits of sediment from ______.
a. erosion by gravity
c. wind erosion
b. water erosion
d. glacial erosion
Name
Date
Class
Chapter Review (continued)
Part B. Concept Review
Directions: Classify each of the following according to its agent of erosion.
1. slump
____________________ 8. abrasion
2. striations
____________________ 9. till
3. creep
____________________ 10. rock slide
4. mass movement
____________________ 11. moraine
5. loess
____________________ 12. deflation
6. outwash
____________________ 13. mudflow
7. horn
____________________ 14. plucking
Directions: Answer the following questions on the lines provided.
15. Name four agents of erosion.
Assessment
17. The Gomez family is building a cabin on a wooded lot on the side of a hill. What problems
might they create that could increase erosion?
18. How does plucking occur? What results from plucking?
34 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
16. Describe ways people can help reduce erosion in areas subject to excessive erosion.
Name
Date
Chapter
Test
Class
Erosional Forces
I. Testing Concepts
Directions: Write the letter of each statement on the lines following the gravity erosion it describes. Items may
be used more than once.
a. This erosion is a mass movement.
b. This erosion usually occurs after a heavy rain in a normally dry area where there are thick
layers of dry sediments.
c. This erosion occurs because underlying materials are weakened and can no longer hold the
eroding materials.
d. This erosion happens most often after heavy rains or during earthquakes.
e. Large blocks of rocks break loose from a steep slope and start tumbling.
f. Loose materials or rock layers slip downslope as a large mass.
g. The deposits from this erosion are usually fan-shaped masses.
h. This kind of erosion is common in areas where freezing and thawing occur.
i. This erosion happens when sediments move slowly down a slope.
1. Mudflows: ______, ______, ______
2. Slump: ______, ______, ______
3. Creep: ______, ______, ______
Directions: Match the descriptions in Column I with the terms in Column II. Write the letter of the correct term
Column II
in the blank at the left.
a. erosion
Column I
5. the dropping of eroded sediments
b. deposition
6. large blocks of rock tumbling down a steep slope
c. building
7. mass movement when sediments slowly inch their way down a slope
d. outwash
8. deposits formed when windblown sediments settle and build up
behind an obstacle
e. dunes
9. wind erosion of loose sediments
f. loess
10. a process that wears away surface materials and moves them to
a different location
11. material deposited by the meltwater from a glacier
12. a mixture of different-sized sediments deposited by a glacier
13. one way to reduce erosion on steep slopes
14. wind deposits of fine-grained sediments
g. deflation
h. planting
i. rockfall
j. till
k. creep
15. an activity that can increase erosion on steep slopes
Erosional Forces
35
Assessment
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
4. Rockfalls: ______, ______, ______, ______
Name
Date
Class
Chapter Test (continued)
Directions: Circle the word in parentheses that makes each statement correct.
16. The four agents of erosion and deposition are wind, (heat, water), gravity, and glaciers.
17. (Transverse, Star) dunes tend to form in regions where wind direction changes.
18. Today, continental glaciers cover about (28, 10) percent of Earth.
19. To protect their fields, farmers may plant belts of trees that act as (drains, windbreaks).
20. (Cirques, Grooves) occur when bedrock is gouged by rock fragments dragged by a glacier.
Directions: Rewrite the following statements changing the italicized words to make the statements correct.
21. Deflation is similar to sandblasting.
22. Much farmland of the midwestern United States is on fertile soil that developed from creep
deposits.
Assessment
24. Eskers are bowl-shaped basins resulting from glacial erosion in the sides of a mountain.
25. Erecting buildings is one of the best ways to reduce erosion.
II. Understanding Concepts
Skill: Sequencing
Directions: For each series, number the events in the order that they could occur.
1. Creep erosion
_____ The soil thaws.
_____ The ground freezes.
_____ The sediment slowly inches downslope.
_____ Expanding ice in the soil pushes up fine-grained sediment particles.
36 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
23. Agents of erosion pick up sediments when they lose their energy of motion.
Name
Date
Class
Chapter Test (continued)
2. Glacial erosion
_____ The glacier loses its energy of motion.
_____ A glacier is formed.
_____ Till is deposited in front of the glacier that has stopped moving.
_____ Striations are gouged into bedrock.
_____ Plucking occurs as the glacier moves.
Skill: Concept Mapping
Directions: Complete the concept map by identifying four types of mass movements caused by gravity.
Gravity
causes
causes
causes
3.
4.
5.
6.
identified by
identified by
identified by
identified by
a curved scar
leaning trees
and fence posts
piles of
broken rock
a fan-shaped
mass
Assessment
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
causes
Skill: Comparing and Contrasting
7. Compare and contrast slump and creep.
Skill: Outlining
8. Complete the outline of erosion and deposition by glaciers.
I. Glacial Erosion
A.
B.
II. Glacial Deposition
A.
1. Moraine deposits
B.
1. Eskers
Erosional Forces
37
Name
Date
Class
Chapter Test (continued)
III. Applying Concepts
Writing Skills
Directions: Answer the following questions in complete sentences.
1. Sand dunes are found on the eastern and southeastern shores of Lake Michigan. However, they
are not found on the western shore of the lake. Why?
Assessment
3. The roots of wheat are not very strong or deep. The roots of prairie grass are strong.
Plowing up a field of prairie grass and planting wheat could lead to erosion. Write a short
paragraph telling why the erosion might occur and suggest what might be done to help stop
the erosion.
38 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
2. Consider two garden plots, one in the open country and one in a major population center.
How would you expect the forces of erosion to be different in these two locations?
Transparency Activities
Transparency
Activities
Erosional Forces
39
Name
1
Date
Section Focus
Transparency Activity
Class
Avalanche
1. Describe what is happening in the photo. How is the land changed
as snow and ice move over it?
Transparency Activities
2. What is the key force in pulling an avalanche downhill?
3. How do you think the steepness of the slope affects avalanches?
40 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Avalanches occur when snow on a mountain slope breaks loose
and slides downhill. Because of avalanche danger, people in snowy,
mountainous areas put a lot of effort into avalanche safety and
control.
Name
2
Date
Section Focus
Transparency Activity
Class
I’ll be back in
5,000 years.
1. How was Ötzi preserved? What do you think modern scientists
have learned from studying Ötzi?
Transparency Activities
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Meet Ötzi, a human from the Stone Age who lived about 5,000 years
ago. He was somehow trapped in a rock depression and subsequently
covered by snow and ice. Ötzi was eventually discovered by hikers on
a ridge that divides Austria from Italy.
2. What happened that resulted in Ötzi’s eventual discovery?
3. In what areas do you most commonly see a lot of snow and ice?
Erosional Forces
41
Name
3
Date
Section Focus
Transparency Activity
Class
Rock on!
Transparency Activities
1. No one has ever seen a rock move at the Racetrack. What
evidence do you have that these rocks are moving without
human interference?
2. Pretend you are scientists studying Death Valley. Develop a
theory that explains the mysterious movements at the Racetrack.
42 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
You may have noticed animal tracks in the sand, but have you ever
seen boulder tracks? If you go to the Racetrack in Death Valley, this is
exactly what you’ll see. Rocks at the Racetrack seem to move without
any help at all!
Transparency Activities
500 km
Teaching Transparency
Activity
0
Date
MEXICO
CANADA
2
UNITED STATES
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Name
Class
Glacial Margin
Erosional Forces
43
Name
Teaching Transparency Activity
Date
Class
(continued)
1. What are the two types of glaciers?
2. Did the continental glaciers cover your area? If so, what evidence of glaciers does your area
show?
3. What are continental glaciers agents of?
4. Name five states in the United States that were covered completely or partially by glaciers.
6. What caused the ice sheets to recede?
Transparency Activities
44 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
5. Which countries on the transparency were glaciated?
Name
Date
Assessment
Transparency Activity
Class
Erosional Forces
Directions: Carefully review the table and answer the following questions.
Soil
Mound
After 1
minute
After 2
minutes
After 3
minutes
A
29.5
28.5
27.5
26.5
25.5
B
28.0
26.5
24.0
22.0
20.0
C
30.0
29.5
29.0
28.5
28.0
D
30.5
30.5
30.5
30.5
30.5
After 4
After 5
minutes minutes
1. According to this information, which mound of soil lost over 5 cm
in height due to wind erosion?
A Mound A
C Mound C
B Mound B
D Mound D
2. If everything remains the same, what would be the height of
Mound B after 10 minutes?
F 12.0 cm
H 5.0 cm
G 8.0 cm
J 3.0 cm
Transparency Activities
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Wind Erosion Experiment Data (Using Fans)
Height of Soil Mound (cm)
3. According to the table, Mound D could probably be composed
of ___.
A dry temperate soil
B loosely packed semi-moist soil
C fine grain sand
D moist clay-like soil
Erosional Forces
45
Teacher Support
and Planning
Teacher Support and Planning
Content Outline for Teaching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T2
Spanish Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T5
Teacher Guide and Answers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T9
Erosional Forces
T1
Section 1
Erosional Forces
Erosion by Gravity
A. Erosion—wearing away and moving of surface materials by gravity,
Underlined words and
phrases are to be filled
in by students on the
Note-taking Worksheet.
water, wind, or glaciers
B. Through the process of deposition, sediments are dropped by erosion agents as
they lose energy.
C. Mass movement occurs as gravity moves materials down a slope as one large mass.
1. Slump—material slips down a curved surface as one large mass.
2. Sediments slowly shift downhill in the process of creep .
3. Rockfalls and rock slides occur when rocks break off or slip suddenly down a hill.
4. A mudflow is a thick mixture of water and sediments flowing downhill.
D. Consequences of erosion—buildings on slopes eventually have problems due to erosion by gravity.
1. Sometimes builders and residents make slopes more unstable by making them steeper.
2. Another source of instability is the removal of vegetation.
E. Steep slops can be made safer with vegetation, drainage pipes, and walls of concrete or railroad ties.
DISCUSSION QUESTION:
How do slump and creep differ? Speed—Slump occurs more quickly than creep does.
Section 2
Glaciers
A. Glacier—large mass of ice and snow slowly moving on land; an agent of erosion
B. As glaciers move, they pick up boulders, gravel, and sand in an erosion process called plucking.
1. Plucked rocks at the base of the glacier scour the soil and bedrock.
2. Dragged rock fragments leave scars on bedrock called grooves.
3. Striations are shallower scars on bedrock.
4. Grooves and striations indicate the direction a glacier moved.
C. As glaciers retreat, they leave behind till, a mixture of different sized sediments.
1. Till areas include wide swaths of farmland from Iowa to Montana, and Ohio to Illinois.
2. A moraine is a ridge, or pile, of deposit left at the end of a glacier.
3. Outwash—material deposited in layers by the meltwater of a glacier, with largest pieces
closer to the glacier
T2 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Teacher Support & Planning
Content Outline
for Teaching
4. An esker is a type of outwash deposit formed as meltwater rivers within the ice deposit sand
and gravel within their channels.
D. Continental glaciers—huge masses of ice and snow now covering only about 10 percent of
Earth in areas near the poles; in the past, as much as 28 percent of Earth was covered by glaciers
1. Periods of widespread glaciation over the last 2 million to 3 million years are known as ice ages.
2. The average air temperature on Earth was about 5°C lower during ice ages than today.
3. The last major ice age was about 18,000 years ago.
E. Valley glaciers—exist in mountains
1. Cirques are bowl-shaped basins in the sides of mountains, created by valley glaciers.
2. A long ridge or árete forms when two valley glaciers erode a mountain side-by-side.
3. A horn forms when valley glaciers erode a mountain from several directions.
4. Glacially eroded valleys have a U shape, as opposed to the V shape left by stream erosion.
F. Glaciers have changed, and continue to change, the shape of Earth’s surface; sand and gravel
deposits left by glaciers are important resources for the construction of roads and buildings.
DISCUSSION QUESTION:
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
How do glaciers cause erosion? By plucking sediments and rocks and depositing them elsewhere
Section 3
Wind
A. Wind erosion—can scatter dust or volcanic ash over thousands of kilometers
1. Deflation—Wind removes small particles of loose sediment, leaving behind heavier materials.
2. Wind behaves like a sandblaster blowing sand grains against rocks wearing them down and
pitting them in the process of abrasion.
3. Deflation and abrasion happen most often in areas where there is little vegetation to hold
sediments in place.
4. When strong winds blow in the deserts, beaches, or dry riverbeds, an airborne sand cloud
or sandstorm occurs.
5. Dust storms occur when winds blow dry topsoil from open fields, overgrazed areas, or
places with little or no vegetation.
Erosional Forces
T3
Teacher Support & Planning
Content Outline for Teaching (continued)
B. Reducing wind erosion—plant vegetation
1. Windbreaks—Rows of trees can slow down wind reducing erosion; they also trap snow to
increase moisture.
2. Roots—Fibrous root system plants such as grasses help anchor soil particles.
C. Deposition by wind—airborne particles eventually return to Earth.
1. Fine-grained sediments known as loess helped form fertile soils in the Midwestern United
States.
2. A mound of sediments drifted by the wind is called a dune.
a. Dunes move as the wind continues to blow against them.
b. The more gently sloping side of a dune faces the wind.
c. Dunes have different shapes, such as crescents, lines, or stars, based on sediments, wind
speed and direction, and vegetation.
D. Erosion and deposition are constantly changing the shape of the land.
DISCUSSION QUESTION:
What are two ways vegetation can help prevent wind erosion? Windbreaks can slow wind down;
roots of plants such as grasses can help hold soil particles.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Teacher Support & Planning
Content Outline for Teaching (continued)
T4 Erosional Forces
Fuerzas erosivas
Erosión causada por la gravedad
Lo que aprenderás
■
■
■
A explicar las diferencias entre erosión y
depositación.
A comparar y contrastar lo que es el
desprendimiento, el corrimiento, los derrumbes, los derrubios de rocas y las corrientes de
lodo.
A explicar por qué no es buena idea construir
edificios en pendientes inclinadas.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Vocabulario
erosion/erosión: proceso en que los materiales
superficiales se desgastan y son transportados
de un lugar a otro por agentes como la
gravedad, el agua, el viento y los glaciares.
deposition/depositación: acción de dejar caer
los sedimentos, la cual ocurre cuando un
agente erosivo, como la gravedad, un glaciar, el
viento o el agua, pierde su energía y no puede
seguir transportando su carga.
mass movement/movimiento de masas:
cualquier tipo de erosión que ocurre a medida
que la gravedad mueve materiales cuesta abajo.
slump/desprendimiento: tipo de movimiento
de masas que se presenta cuando una masa de
material se mueve cuesta abajo por una
pendiente curva.
creep/corrimiento: tipo de movimiento de
masas en el cual los sedimentos se mueven
cuesta abajo paulatinamente; es común en
áreas de congelamiento y derretimiento;
puede hacer que las paredes, los árboles y las
cercas se inclinen.
Por qué es importante
■
La erosión formó muchas de las características naturales del planeta.
Los glaciares
Lo que aprenderás
■
■
A explicar cómo se mueven los glaciares.
A describir pruebas de la erosión y
depositación causadas por glaciares.
■
A comparar y contrastar la tilita y los derrubios.
Vocabulario
glaciers/glaciares: extensas masas de hielo y
nieve en movimiento que cambian grandes
regiones de la superficie terrestre, a través de
la erosión y la depositación.
plucking/ablación: proceso mediante el cual se
agrega grava, arena y piedras a las partes inferior y lateral de un glaciar conforme el agua se
congela y derrite, rompiendo fragmentos de la
roca circundante.
till/tilita: mezcla de sedimentos de diferentes
tamaños que un glaciar en retirada deja caer
de la base y que puede cubrir inmensas áreas
de terreno.
moraine/morrena: extenso banco de rocas y
suelo que un glaciar deposita cuando se
detiene su movimiento.
outwash/derrubio: material depositado por el
agua derretida de un glaciar.
Por qué es importante
■
La erosión y la depositación glaciares crean
muchos relieves terrestres.
Surcos glaciares
En las regiones montañosas del mundo,
200,000 glaciares de valle se mueven en
respuesta a la gravedad.
Preguntas del mundo real
■ ¿Cómo se ve afectado el terreno cuando un
glaciar de valle se mueve cuesta abajo?
Materiales
■ arena
■ bandeja grande de plástico o metal
■ mesa de corrientes*
■ bloque de hielo
■ libros (2 ó 3)
■ bloque de madera*
■ regla métrica
■ fuente de luz con reflector
*Materiales alternativos
Fuerzas erosivas
T5
Teacher Support & Planning
Spanish
Resources
Medidas de seguridad
Datos sobre el glaciar
Datos de
muestra
PRECAUCIÓN: No botes arena por las tuberías.
Asegúrate de que la fuente de luz esté conectada a
un enchufe GFI. No toques la fuente de luz
porque puede estar caliente.
Metas
■ Comparar los valles esculpidos por corrientes
de agua y por glaciares.
Procedimiento
1. Arregla la bandeja con arena como se muestra. Coloca los libros bajo uno de los
extremos de la bandeja para hacer un
declive.
2. Corta un canal estrecho, como un río, a
través de la arena. Mide y anota su ancho y
su profundidad. Haz un diagrama que
incluya estas medidas.
3. Coloca la fuente de luz para que brille sobre
el canal, como se muestra.
4. Fuerza el bloque de hielo presionándolo en
la arena en la parte superior del canal.
5. Con cuidado, empuja el bloque de hielo
hacia abajo del canal hasta que esté a mitad
de camino entre la parte superior y la inferior de la bandeja y quede directamente bajo
la luz.
6. Prende la luz para que el hielo se deshaga.
Anota lo que sucede.
7. Anota el ancho y profundidad del canal de
hielo. Haz un dibujo a escala.
Concluye y aplica
1. Explica cómo puedes determinar la dirección del movimiento del glaciar a partir de
la posición de los depósitos.
2. Explica cómo se determina la dirección de
movimiento del glaciar, según los
movimientos de los sedimentos depositados
por el aguanieve.
3. Describe cómo afectan los glaciares de valle
las superficies por donde se mueven.
T6 Fuerzas erosivas
Ancho Profundidad Observaciones
(cm)
(cm)
Canal
original
1–2
3
El canal de la
corriente tiene
forma de V.
Canal del
glaciar
8
4
Canal con
forma de U
Canal del
aguanieve
1–2
3.5
Canal con
forma de V
El viento
Lo que aprenderás
■
■
A explicar cómo causa deflación y abrasión el
viento.
A reconocer cómo se forman el loes y las
dunas.
Vocabulario
deflation/deflación: tipo de erosión que se presenta cuando el viento sopla sobre sedimentos
sueltos, extrae micropartículas y deja atrás
sedimentos más gruesos.
abrasion/abrasión: tipo de erosión que ocurre
cuando los sedimentos soplados por el viento
golpean rocas y sedimentos, puliendo y
dejando huecos en su superficie.
loess/loes: depósito de sedimentos firmemente
compactados y de granos finos que es
arrastrado por el viento.
dune/duna: montículo que se forma cuando los
sedimentos arrastrados por el viento se acumulan detrás de una barrera; relieve común
en las regiones desérticas.
Por qué es importante
La erosión y la depositación causada por el
viento cambian los paisajes, especialmente en
climas secos.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Teacher Support & Planning
Spanish Resources (continued)
Diseña tu propio
Soplados por el
viento
Preguntas del mundo real
¿Alguna vez has estado jugando un deporte
afuera cuando de repente el viento te sopló
polvo en los ojos? ¿Qué hiciste? ¿Le diste la
espalda? ¿Te cubriste los ojos? ¿De qué forma
recoge el viento los sedimentos? ¿Por qué el
viento levanta algunos sedimentos y deja otros
atrás?
Formula una hipótesis
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
¿Cómo afecta la humedad de los sedimentos, la
capacidad erosiva del viento? ¿Es la velocidad
del viento un factor que limita el tamaño de los
sedimentos que el viento puede transportar?
Formula una hipótesis sobre cómo la humedad
de los sedimentos afecta la erosión causada por
el viento. Formula otra hipótesis sobre la forma
en que la velocidad del viento afecta el tamaño
del sedimento que el viento puede transportar.
Metas
■ Observar el efecto de la humedad del suelo y
de la velocidad del viento en la erosión causada por el viento.
■ Diseñar y llevar a cabo experimentos que
pongan a prueba los efectos de la humedad
del suelo y la velocidad del viento sobre la
erosión causada por el viento.
Posibles materiales
■ bandejas planas (4)
■ arena fina (400 mL)
■ grava (400 mL)
■ secadora de pelo
■ regadera
■ agua
■ láminas de cartulina de 28 cm × 35 cm (4)
■ cinta adhesiva
■ tazón para mezclar
■ regla métrica
■ indicador de la velocidad del viento
Medidas de seguridad
Usa gafas de seguridad durante todo el tiempo
que dirijas la secadora de pelo hacia los sedimentos. Asegúrate de que la secadora esté
conectada a un enchufe eléctrico GFI.
Usa métodos científicos
Prueba tus hipótesis
Diseña un plan
1. En grupo, lleguen a un acuerdo y escriban
las dos hipótesis.
2. Enumera los pasos necesarios para probar la
primera hipótesis. Planifica pasos específicos
y varía un sólo paso a la vez. Enumera los
pasos necesarios para poner a prueba la
segunda hipótesis. Pon a prueba un sólo factor a la vez.
3. Mezcla los sedimentos en las bandejas.
Piensa en cómo doblar las láminas de cartulina y cómo adherirlas a las bandejas para
mantener los sedimentos dentro de las bandejas.
4. En tu Diario de ciencias, diseña tablas de
datos. Utilízalas a medida que tu grupo
recoge datos.
5. Identifica todas las constantes, variables y
controles del experimento. Un ejemplo de
un control es una bandeja con sedimentos
que no se exponen al viento.
Sigue tu plan
1. Asegúrate que tu maestro(a) apruebe tu
plan antes de comenzar.
2. Realiza los experimentos según lo planificado.
3. Al realizar los experimentos, escribe las
observaciones que tú o tus compañeros
hagan. Resume tus datos en las tablas de
datos que diseñaste en tu Diario de ciencias.
Analiza tus datos
1. Compara tus resultados con los de otros
grupos. Explica qué pudo haber causado las
diferencias entre los grupos.
Fuerzas erosivas
T7
Teacher Support & Planning
Spanish Resources (continued)
2. Explica la relación entre la velocidad del
viento y el tamaño de los sedimentos que
transporta.
Concluye y aplica
1. ¿Cómo afecta la energía de movimiento del
viento su capacidad para transportar sedimentos?
2. Explica la relación entre la humedad del
sedimento y la cantidad de sedimento que
mueve el viento.
Guía de estudio
Sección 3 El viento
1. La deflación ocurre cuando el viento erosiona sólo los sedimentos de grano fino,
dejando atrás los sedimentos más grandes.
2. La abrasión es el desgaste y ahuecamiento de
la roca y los sedimentos por la acción del
viento.
3. Los depósitos transportados por el viento
incluyen el loes y las dunas. El loes consta de
partículas de grano fino compactadas. Las
dunas se forman cuando los sedimentos que
sopla el viento se acumulan detrás de un
obstáculo.
Repasa las ideas principales
Sección 1 Erosión causada por la gravedad
1. La erosión es el proceso que desgasta y
transporta sedimentos.
2. La depositación ocurre cuando un agente
erosivo pierde energía y no puede ya llevar
su carga de sedimentos.
3. El desprendimiento, el corrimiento, los
derrubios de rocas y las corrientes de lodo
son todos movimientos de masas causados
por la gravedad.
Sección 2 Los glaciares
1. Los glaciares son agentes erosivos poderosos.
Cuando el agua se congela y se descongela
en las grietas, quiebra trozos de las rocas circundantes. Estos trozos luego se incorporan
al glaciar mediante la ablación.
2. A medida que el sedimento enterrado en la
base del glaciar se mueve sobre el suelo, se
forman surcos y estriaciones. Los glaciares
depositan dos tipos de materiales: tilita y
derrubios.
T8 Fuerzas erosivas
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Teacher Support & Planning
Spanish Resources (continued)
Hands-On Activities
MiniLAB (page 3)
1. The gelatin powder washed away, causing the
gravel and pebbles to slip down the pan.
2. The inclined pan models a steep slope and the
water from the watering can models rain. Erosion
of base sediments combined with gravity causes
slump.
MiniLAB: Try at Home (page 4)
1. Students’ drawings should clearly show a branching fibrous root system.
2. Grass roots branch out under the shaft of the
grass, forming a root network that holds soil
particles.
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Lab (page 5)
Lab Preview
1. as a reminder to be careful when using light
sources that heat up
2. Yes, because a glacier will remove rock and soil
from the sides of a valley making it more Ushaped.
Data and Observations
Glacier Data
Answers will vary with students’ results.
Conclude and Apply
1. Small hills of till mark the end position of a
glacier in its valley.
2. Large outwash sediments are deposited closest to
the glacial front. Smaller sediments are carried
farther from the front.
3. Valley glaciers produce U-shaped valleys with
steep sides and relatively flat bottoms.
Lab: Design Your Own (page 7)
Lab Preview
1. To protect eyes from blowing sand.
2. Yes. The more powerful the wind, the more material it can move around.
Analyze Your Data
1. Results could vary slightly with variations in
experimental design and procedure.
2. The greater the wind speed, the larger the sediments it moved.
Conclude and Apply
1. When energy of motion increases, erosion
increases. The greater the wind speed, the greater
the amount of erosion.
2. Moist sediments are not easily eroded.
Laboratory Activity 1 (page 9)
Data and Observations
Answers will vary with students’ results.
Questions and Conclusions
1. creep—slow
2. mud flow—rapid
3. the slope of the stream table
4. landslide—rapid
5. mudflow; the water saturates the loosely patched
soil and rock. The entire mass of debris then
moves down the slope.
6. mudflow. A mudflow moves suddenly, carrying
automobiles and houses and burying roadways.
the movement of creep is so slow that it causes
only minor surface disturbances. Vegetation holds
the soil in place fairly well.
7. Vegetation is planted; walls are built to block
slides; water drainage is improved.
Laboratory Activity 2 (page 11)
Questions and Conclusions
Valley glaciers begin as snowfields that form where
the snowfall is heavy and temperatures are cold
enough for the snow to remain throughout the year.
When the accumulation reaches a depth of 30–60
meters, the bottom layers become ice and the mass
begins to move down the valley. Valley glaciers make
the landscape more rugged. They form peaks called
horns, U-shaped valleys, and hanging valleys.
Lab Note: You may want to have students model an
area that was covered by a continental glacier. The
lake area of Minnesota and the upper New York
State area are good examples. Students could work
from topographic maps.
Meeting Individual Needs
Directed Reading for Content Mastery (page 15)
Overview (page 15)
1. gravity
2–4. creep, slump, mudflow
5. glaciers
6–7. plucking, outwash deposits
8. wind
9. deflation
Sections 1 and 2 (page 16)
1. rock slides
2. mudflows
3. rocks carried by glaciers
4. glacier melts and retreats
5. creep occurs
6. plants removed from hilly areas
7. increased erosion
8. decreases
9. gravity
10. creep
11. grooves
12. Continental
Erosional Forces
T9
Teacher Support & Planning
Teacher Guide
& Answers
13. glaciers
14. Thousands
15. moraine
Section 3 (page 17)
1. materials
2. deflation
3. abrasion
4. storm
5. windbreaks
6. root
7. loess
8. Dunes
9. facing
10. away
11. barchan
12. sandstorm
13. vegetation
Key Terms (page 18)
1. a
2. e
3. f
4. i
5. d
6. g
7. j
8. c
9. k
10. b
11. h
12. m
13. n
14. l
Lectura dirigida para Dominio del contenido (pág. 19)
Sinopsis (pág. 19)
1. gravedad
2–4. corrimiento, derrumbe, corriente de lodo
5. glaciares
6–7. ablación, depósitos derrubiados
8. viento
9. deflación
Secciones 1 y 2 (pág. 20)
1. derrubios de rocas
2. corrientes de lodo
3. rocas que transportan los glaciares
4. el glaciar se derrite y se hace más pequeño
5. ocurre el corrimiento
6. las plantas se eliminan de áreas empinadas
7. aumenta la erosión
8. disminuye
9. gravedad
10. corrimiento
11. acanaladuras
12. continental
13. glaciares
14. miles
15. morrena
T10 Erosional Forces
Sección 3 (pág. 21)
1. materiales
2. deflación
3. abrasion
4. tormenta
5. rompevientos
6. raíces
7. loes
8. Las dunas
9. dan cara
10. en dirección contraria
11. barján
12. tormenta de arena
13. vegetación
Términos claves (pág. 22)
1. a
2. f
3. h
4. l
5. e
6. i
7. m
8. d
9. n
10. b
11. j
12. c
13. g
14. k
Reinforcement (page 23)
Section 1 (page 23)
1. a. slump
b. rock slides
c. mudflows
d. creep
2. They are all mass movements. All occur on
slopes. All are most likely to happen after a
heavy rain. All erode sediments from the top
of a slope to farther downhill.
3. a. creep
b. slump
c. mudflows
d. rock slides or rock falls
4. No. Creep occurs most commonly in areas
where the ground freezes and thaws.
5. A mudflow might take place. Rain water can
cause the layers of dry clay and dirt to form a
thick mud. Gravity can cause this mass, including the houses, to slide to the bottom of the hill.
Section 2 (page 24)
1. All glaciers are thick masses of ice that move
slowly on land. They form on land where temperatures are cold enough for snow to remain
all year. They erode by moving loose sediments
and by plucking. They leave till and outwash
deposits as they lose their energy of motion.
2. Valley glaciers form in mountainous areas and
flow down mountain slopes and valleys causing
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Teacher Support & Planning
Teacher Guide & Answers (continued)
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
erosion. They may create cirques, aretes, and
horns. They erode valleys in a U-shape. Continental glaciers form near Earth’s polar regions
and today are found only in Greenland and
Antarctica. During an ice age continental glaciers cover huge areas of Earth’s surface.
3. valley
4. continental
5. continental and valley
6. continental and valley
7. continental and valley
8. continental
9. valley
10. valley
Section 3 (page 25)
1. abrasion
2. Dunes
3. loess
4. Loess
5. deposition
6. Abrasion
7. dunes
8. wind
9. deposits
10. Deflation
11. steeper
12. Wind
13. sandstorm
14. Dust storms
15. Windbreaks
16. vegetation
17. root
18. barchan
Enrichment (page 26)
Section 1 (page 26)
Student responses will vary, but they should include
information regarding a specific landslide that identifies its location, causes, degree and type of damage,
and date of incidence. Students should identify their
sources of information.
Section 2 (page 27)
1. This occurs when the base of an ice sheet is near
the melting point and some water is present to
reduce friction.
2. Movement of material such as ice under intense
pressure.
3. the finely ground remains of rock produced where
the rock studded base of a glacier moves across a
valley floor
4. a depression in glacial drift remaining after the
melting of an isolated mass of buried ice
5. the breaking away of a mass of ice from a glacier
to form an iceberg
6. a continental glacier that obscures all but the
highest peaks of a large part of a continent
7. a long ridge or oval-shaped hill formed from
glacial drift
8. area of a glacier where additions of snow exceed
losses from melting, evaporation, and sublimation
9. area of a glacier where losses of ice from melting,
evaporation, and sublimation exceed additions of
snow annually
Section 3 (page 28)
1. currents (natural), tectonic plate movements (natural), earthquakes (natural), waves (natural), tides
(natural), winds (natural), over-development of
land (human), construction of harbors (human),
jetties (human)
2. It protects the buildings by acting as a barrier
between the oceanfront property and the sea.
3. It was certainly worth it to the people who lived
there because it saved their homes; it may not
have been worth it to the other taxpayers who
paid the bill and got nothing in return.
Note-taking Worksheet (page 29)
Refer to Teacher Outline, student answers are
underlined.
Assessment
Chapter Review (page 33)
Part A. Vocabulary Review (page 33)
1. a (2/1)
2. b (1/1)
3. a (8/3)
4. d (4/2)
5. a (5/2)
6. d (5/2)
7. c (1/1)
8. c (2/1)
9. b (2/1)
10. a (8/3)
11. c (5/2)
12. b (6/2)
13. b (3/1)
14. d (4/2)
Part B. Concept Review (page 34)
1. gravity (2/1)
2. glacier (5/2)
3. gravity (2/1)
4. gravity (2/1)
5. wind (8/3)
6. glacier (6/2)
7. glacier (5/2)
8. wind (7/3)
9. glacier (6/2)
10. gravity (2/1)
11. glacier (5/2)
12. wind (7/3)
13. gravity (2/1)
14. glacier (5/2)
15. gravity, moving water, wind, glaciers (1/1)
16. People can plant vegetation. The plant roots will
hold the soil and the plant will absorb water.
Erosional Forces
T11
Teacher Support & Planning
Teacher Guide & Answers (continued)
People can build retaining walls to keep soil and
rocks from sliding downhill. People can also
install drainage pipes and tiles to carry water
away. (3/1)
17. To build the cabin the Gomezes will have to
clear vegetation. Since vegetation helps reduce
to hold soil in place, removing it might lead to
greater erosion. They probably will dig into the
hill, making it more steep. This too could lead
to greater erosion. (3/1)
18. Plucking occurs when meltwater at the base of a
glacier runs into cracks of rocks and refreezes.
Thawing and freezing expands the cracks and
fractures rocks. As the glacier continues to
move, the rocks get pulled, or plucked, out of
the ground and become part of the glacier. (5/2)
Chapter Test (page 35)
I. Testing Concepts (page 35)
1. a, b, g (2/1)
2. a, e, f (2/1)
3. a, h, i (2/1)
4. a, d, e h (2/1)
5. b (1/1)
6. i (2/1)
7. k (2/1)
8. e (8/3)
9. g (7/3)
10. a (1/1)
11. d (6/2)
12. j (6/2)
13. h (3/1)
14. f (8/3)
15. c (3/1)
16. water (1/1)
17. Star (8/3)
18. 10 (4/2)
19. windbreaks (7/3)
20. Grooves (5/2)
21. Abrasion is similar to sandblasting. (7/3)
22. Much farmland of the midwestern United States
is on fertile soil that developed from loess
deposits. (8/3)
23. Agents of erosion deposit sediments when they
lose their energy of motion. (1/1)
24. Cirques are bowl-shaped basins resulting from
glacial erosion in the sides of a mountain. (5/2)
25. Planting vegetation is one of the best ways to
reduce erosion. (3/1)
II.
1.
2.
3.
4.
5.
6.
7.
Understanding Concepts (page 36)
3, 1, 4, 2 (2/1)
4, 1, 5, 3, 2 (4, 5/2)
slump (2/1)
creep (2/1)
rock slides (2/1)
mudflows (2/1)
Slump takes place on slopes when loose materials or rock layers slip downward as one large
mass. Creep takes place on hills where sediments move very slowly downslope. (2/1)
8. I. Glacial Erosion
A. Scouring
B. Plucking
II. Glacial Deposition
A. Till
1. Moraine deposits
B. Outwash deposits
1. Eskers (5/2)
III. Applying Concepts (page 38)
Writing Skills
1. The prevailing winds in this area are from the
west and northwest, causing sand to build up on
the beaches on the eastern and southeastern
shores. These winds tend to blow the sand on
the western shore into the lake before the sand
reaches an obstacle. (8/3)
2. The plot in the country could suffer more wind
erosion. The major city’s buildings would help
protect the city plot from wind erosion. The
country plot is also more likely to suffer from
water erosion. The city plot would be protected
from heavy runoff by curbs. (7/3)
3. Because the roots of wheat are not strong or
deep, they would not hold the soil as well as
prairie grass. As a result, erosion of the soil
might occur when it rains. To stop the erosion,
the farmer could leave some of the prairie grass
and plant trees as windbreaks around the field.
If the field is on a slope, the farmer might build
walls or install a drainage system. (7/3)
Transparency Activities
Section Focus Transparency 1 (page 40)
Avalanche
Transparency Teaching Tips
This transparency introduces erosion through
mass movement. Point out that mass movement
erosion is caused by gravity impelling material
down a slope.
■ Ask the students to name other, similar movements
(rockfalls, rock slides, mudflows, and slumps).
■ Explain each type of mass movement and how
water often works in conjunction with gravity to
cause mass movements.
■
T12 Erosional Forces
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Teacher Support & Planning
Teacher Guide & Answers (continued)
Content Background
In a slump, layers of rock on a steep, curved slope
can no longer be supported by the material
beneath and slip down the slope as a mass.
■ Rock falls and rock slides often occur in the
spring as ice thaws and freezes, opening up cracks
in the rocks. Gravity carries the broken pieces
down slope, causing collisions with more rocks.
The result is a cascade of rocks downhill.
■ Mudflows tend to occur in dry areas after a heavy
downpour. The ground becomes saturated, and
gravity pulls the mud mass downhill.
■ The term landslide refers to any of the mass
movements described above (or a combination of
them).
■ Avalanches are usually started due to weather conditions, although some are triggered by noise and
skiers.
Answers to Student Worksheet
1. Snow and ice are crashing down a mountain. The
avalanche carries rock and debris downhill, and
can damage trees and shrub it moves over.
2. Gravity is the key force in avalanches.
3. The steepness of the slope affects both the likelihood of an avalanche and the force with which it
is pulled downhill.
■
Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc.
Section Focus Transparency 2 (page 41)
I’ll be back in 5,000 years.
Transparency Teaching Tips
The concept introduced here is glaciers. Explain
that glaciers are huge masses of ice that usually
move less than 30 cm (one foot) per day.
■ Ask the students to describe the forces that cause
a glacier’s motion (gravity, melting and refreezing,
and pressure from overlying ice layers).
■ Point out that glaciers scour and pluck, slowly
eroding Earth’s surface.
■ Under normal circumstances, Ötzi would have
been ground to pieces by the glacier. In his search
for shelter, however, he huddled in a rocky hollow.
There he froze to death and remained undisturbed. Slowly, the glacier moved over Ötzi, finally
covering him. Melting of his section of the glacier
in 1991 permitted his discovery by hikers.
Content Background
■ Ötzi had several recently broken ribs and a broken
nose, indicating a possible fall. He died of exposure. Ötzi was approximately 1.6 m (5 feet 2
inches) tall and weighed 50 kg (110 pounds). He
was clothed in an unlined robe of furs of various
kinds. He had a grass cape, a fur hat, and grassstuffed leather shoes. He was 25–35 years old
when he died.
■ Ötzi spent six years at the University of Innsbrunch in Austria, where he was studied in detail.
He was recently returned to Italy, where he will
■
reside in the Archeological Museum of Bolzano.
Ötzi was discovered by Austrian hikers in the Italian Alps (300 feet from the border of Austria).
Answers to Student Worksheet
1. Ötzi was preserved by snow and ice. Scientists
learned a lot about life 5,000 years ago from him,
such as the type of the clothing people wore and
the food they ate.
2. The part of the glacier that covered him began to
melt, and eventually he was uncovered.
3. Answers will vary. Students will probably indicate
there is more snow in the mountains and as you
move closer to the north and south poles.
Section Focus Transparency 3 (page 42)
Rock On!
Transparency Teaching Tips
Ask the students if they have heard any stories
about objects or stones that apparently moved
mysteriously. Were unusual and inexplicable
forces at work, or did each mystery have a rational
explanation?
■ Have the students examine the transparency and
conjecture how such rocks and boulders apparently moved on their own. What forces might be
at work?
Content Background
■ The Racetrack in Death Valley is a type of formation called a playa (a large, flat depression).
■ The movement of stones across the three-mile salt
bed at Racetrack Playa in Death Valley, California,
is well-documented. One large rock was shown to
have moved over 60 meters (200 feet) in the early
to mid 1970s. Some boulders weighing as much as
half a ton have moved.
■ Scientists have sought to unravel this mystery. It
appears that two natural phenomena are at work.
High velocity winds sweep through the region and
over the dry lake bed. In addition, the little rainfall the area receives (less than five centimeters
annually) comes in sudden and violent downpours. Because of the composition of the surface
of the lakebed (fine clay), it is very slick when it is
wet. This may lower friction enough for the
strong, swirling winds to move the boulders.
Another theory adds the possibility of freezing
conditions and ice to lower the coefficient of friction.
Answers to Student Worksheet
1. There are no foot or vehicle tracks, and there are
trails behind the rocks.
2. Answers will vary. Some students may suggest the
wind or even earthquakes as possible forces
behind the movements. See Content Background.
■
Erosional Forces
T13
Teacher Support & Planning
Teacher Guide & Answers (continued)
Teaching Transparency (page 43)
Glacial Margin
Section 2
Transparency Teaching Tips
Use the transparency to identify the areas covered
by the continental glaciers. Point out that the
agents of continental glaciers and valley glaciers
are erosion and deposition.
■ Use the transparency to discuss the features
formed by continental glaciers. Ask students to
describe each feature.
Reteaching Suggestion
■ Have students reread the section on continental
glaciers. Discuss with students the vocabulary.
Extensions
■ Challenge: Have students do research to find out
more about continental glaciers. Have them do an
oral presentation discussing where continental
glaciers were, and what remained when they
receded.
■ Activity: Have students find pictures of features
formed by continental glaciers, Suggest they label
the features and display them in the classroom.
Answers to Student Worksheet
1. continental and valley glaciers
2. Answers will vary.
3. erosion and deposition
4. Answers will vary.
5. United States and Canada
6. The ice sheets receded by melting.
■
Assessment Transparency (Page 45)
Erosional Forces
Section 3
Answers
1. B. Students need to use the information in the
chart and compare the heights of the soil during
the course of the experiment in order to determine which mound of soil lost over 5 cm in
height.
Choice A: No, Mound A only lost a total of 4 cm
during the course of the experiment.
Choice B: Yes, the only Mound that lost more than
3 cm from its original height is Mound B.
Choice C: No, Mound C only lost 2 cm.
Choice D: No, Mound D did not lose any of its
original height.
2. F. Students need to figure out the rate at which
Mound B is eroding. Based on the information in
the chart, Mound B is eroding at a rate of 8 cm
every 5 minutes. Students can then determine that
Mound B would lose 16 cm in 10 minutes. Since
Mound B begins at a height of 28 cm, the correct
answer is choice F, 12 cm.
T14 Erosional Forces
3. D. Students need to understand that a moist, claylike soil would be very stable and probably would
not be affected by the wind from the fan. Choices
A, B, and C are all types of soil that would be
affected by the wind and would experience erosion.
Test-Taking Tip
Encourage students to carefully read the text that
describes the table as it may contain information
necessary to answer the questions.
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Teacher Support & Planning
Teacher Guide & Answers (continued)