stem

iii

Earthquakes

Science, Technology, Engineering, and Mathematics Each day, our lives are filled with more and more products and services that are the result of technology and engineering. The application of scientific concepts to solve a problem or provide a solution is the basis of technology. Engineering links scientific discovery with the development of a practical, real product. Engineers design materials and products that make life easier and keep us safe. Measuring the absorbency of a paper towel or the amount of energy a fluorescent lightbulb saves over an incandescent one, or calculating how fast a computer boots up, are just a few examples of how math is embedded in the development of technological products and solutions. This interconnectedness of science, technology, engineering, and mathematics is known as STEM. Each STEM field is connected to the others in important ways. For instance, without engineering, electricity may have remained an exciting lab phenomenon.

Students will quickly learn technology encompasses them daily and why it is so important. Researchers strive to produce vaccinations for new strains of viruses. Engineers create new sound and light technology so seeing a movie is more enjoyable or looking at a computer screen is easier on the eyes. Engineers also work to develop lighter and stronger materials for use in bicycles, skateboards, and electronics. STEM fields even impact things we might take for granted, such as the design of a toothbrush or the materials that make up a juice box.

In addition to the application of science, technology, engineering, and mathematics concepts, creativity and imagination are essential for designing successful solutions for real-world problems. New products fuel scientific discovery, which inspires engineering, which results in even newer, faster, and more effective technology and products. The activities in this book are meant to encourage creative thinking and problem solving as students implement the design process.

The activities in this book use an eight-step design process, which is described on the following pages. A blackline master of the design process as it is presented in this book is provided on pages vii-viii. Provide a photocopy of these pages to each student as you introduce the idea of STEM activities. The pages will also serve as a reference for students as they work through the design process.

Each step of the design process is associated with the critical thinking skills of Bloom’s Taxonomy, as shown on pages iv and v of this activity book. Because the design process incorporates all levels of thinking, students may get stuck or feel frustrated with a particular step. Use the tips provided in the chart on page vi to help students apply specific critical thinking skills to challenging steps.

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Earthquakes

How To Use This ProgramSTEM is the application of science, technology, engineering, and math concepts to real-world problems. The goal of STEM is to instill in students an understanding of how to apply science, technology, engineering, and mathematics toward solving problems. STEM is also a way to teach and reinforce deeper understanding through practical experience with the content. The goal of the STEM topic booklets is to have students use the design process to solve a real-world problem while introducing them to a science topic through hands-on, project based learning. Each STEM topic booklet focuses on a Big Question that reflects a real-world problem that students will explore in the STEM project. The Big Question is the unifying theme that connects the areas of science, technology, engineering, and math.

In each STEM booklet, students are introduced to the topic through class discussion and a hands-on activity. A Quick Lab then provides practical, hands-on experience with the some facet of the topic. Content refreshers and vocabulary worksheets provide a minds-on introduction to the topic. Math worksheets provide exposure and reinforcement of math skills that students will need to be successful during hands-on activities. The introduction gets the minds of the students focused on different aspects of the topic.

Following the topic introduction, students get to the heart of developing their understanding of the topic. After a worksheet that highlights a real-world technological application from the topic, students will do the core of the module, the STEM project. In the STEM project, students are challenged to answer the big question by incorporating what they have learned about the topic with the design process to solve a real-world problem. A STEM career is then highlighted so that students can see a real-world application of the topic and the skills they have been using. A chance to elaborate on the topic is provided with a Science Inquiry Lab and an enrichment activity.

A number of evaluations and reviews can be used to assess students knowledge of the science, technology, engineering, and math used in exploring the topic. A Review and Reinforce worksheet of the content provides students an opportunity to clarify the content they have learned. As formal assessment, there is a Topic Assessment test. Finally, students have a performance assessment that wraps up the module by assessing their understanding of the content and the design process.

After completing a STEM topic booklet, students will have experienced solving a real-world problem to a science topic using the design process. Students will also have a deeper understanding of a topic because they will have experienced the topic in a real-world manner that is relevant and immediate. By providing hands-on, project based experiences for students, the STEM modules are designed to help students take ownership of their own learning and understanding. The open ended nature of the STEM activities are designed so that students use the framework of the Big Question to determine not only how they will answer the question, but how they will learn to learn.

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Earthquakes

The Design Process Identify the ProblemAt the beginning of each activity, students are asked to identify the problem that their designs will address. This step is important because it informs the rest of the design process and defines how success will be measured. The scenarios presented in the book vary. Some are true problems that need to be solved, such as how to safely filter water samples. Others focus on improving an existing design, such as building a device that allows students to flip a light switch from across the room. A handful are more conceptual in nature. For example, students would not be expected to design an actual dam and experiment with water flow to observe effects on the environment. The purpose of activities such as these is to help students understand some basic design concepts and apply those concepts to different problems or tasks.

Do ResearchAfter a problem has been identified, students conduct research. This research may include finding articles in books, magazines, or on the Internet to help students begin to formulate ideas and recognize constraints for their designs. During this stage, students examine existing designs, which can provide a starting place and help students formulate questions. Research is also the step in which students discover and explore the important elements of a design. Guided questions encourage critical thinking about aspects of the problem that must be addressed in order to develop a successful design.

In each activity, the research step includes the question, What are your design constraints? This question helps students recognize the limits of their solutions and to eliminate solutions that would be inefficient, costly, or physically impossible.

Develop Possible SolutionsNext, students brainstorm possible design solutions that address the problem they identified. Possible solutions may include variations on one design using the same or different materials. They also may include completely different designs. This step allows students to recognize the pros and cons of each design.

Choose One SolutionIn this step, students choose one of their proposed designs and describe it in detail. They may be asked to draw or diagram their design and to explain why they chose it. Having as much information as possible about each possible solution and keeping the problem or task in mind is helpful for choosing a successful design. The chosen design should represent the solution that students think best meets the need or solves the problem that was identified at the beginning of the design process.

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Earthquakes

Design and Construct a PrototypeAt this point in the design process, students gather materials, build a prototype, and record the particular details of a design that are required for replication. These requirements—such as dimensions, measurements, materials, processes, and so on—are described in a detailed description or assessment. Anything that someone studying or replicating the prototype would need to know should be included in this section.

At the end of this step, students have a prototype that is ready for testing. By definition, a prototype is the original or base model. This concept is important for students’ understanding of the design process and the fact that a successful prototype is not necessarily one without problems. Scientists usually change their prototypes multiple times before they get it to do what they want.

Test the PrototypeAfter building their prototypes, students will test it. Some of the activities produce prototypes that can be tested within a class period; others involve several days of testing. Students may be asked to construct graphs, tables, or to record their results in other ways. Testing the prototype usually involves asking questions that are based on observations, and assessing the prototype in terms of how well it solves the problem or task. Again, it is important for students to understand that a successful prototype is not a perfect prototype, but one that helps the designer refine his or her design.

Communicate ResultsSharing results is an important step in any developing design. Students are encouraged to use a variety of approaches to communicate their results. Examples include sketches, photographs, detailed diagrams, word descriptions, portfolios, computer simulations, computer slide shows, and video presentations. Students may also present evidence that was collected when the prototype was tested. This evidence may include mathematical representations, such as graphs and data tables, that support the design choice. Students can talk about how well a particular solution worked and learn how other students approached the problem.

It is important for students to understand that this step is not a competition. Communicating the results of an experiment or test has practical and ethical importance for scientists and engineers. Practically, communicating results opens a conversation in which other scientists or engineers can make suggestions and help improve a design. The design also might help the other engineers solve problems they are having with their own designs or inspire them with a new design. Ethically, communicating results opens an experiment or design to accurate, unbiased evaluation. It also helps protect the intellectual rights of the scientists or engineers sharing the design.

Evaluate and RedesignThe last step allows students to evaluate what worked and what did not work about their designs and why. Students are asked to rate their prototype designs with a rubric of design constraints. Students are encouraged to explain their ratings and, if needed, brainstorm design improvements. Some activities allow the students to redesign their prototype, but because of time and material constraints, other activities only engage students in a discussion.

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Earthquakes

The Design Process and Higher-Order Thinking Skills

Act

ivity Step in

the Design Process

Critical Thinking

Skills

Level of Difficulty

Teaching Tips

Ques

tionin

g

Identify the Problem Recalling,

UnderstandingBasic

Remind students that their designs will be based on the problem they identify and their research. Specificity and thoroughness are therefore paramount.

Do Research

Imagin

ing

Develop Possible Solutions

Applying, Analyzing

Intermediate

Developing possible solutions is the brainstorming step. Remind students to use their research and consider their design constraints as they develop possible solutions but also encourage them to think outside the box.

Pla

nnin

g

Choose One Solution

Analyzing, Evaluating, Creating

Intermediate to Difficult

To assist students’ choice of a design, you might help them create a checklist of characteristics that a successful design needs. However, students may have different reasons for choosing a solution. Allow students to choose less practical designs for experimentation and demonstration purposes.

Cre

ating Design and

Construct a Prototype

Creating DifficultRemind students that a good design that is poorly executed will not produce favorable or accurate results. Taking time and being precise are important.

Evalu

ating

Test the Prototype

Applying, Analyzing, Evaluating, Creating

Intermediate to Difficult

Unsuccessful designs are to be expected. Treat them as learning opportunities as opposed to failures. Remind students that the design process might be more appropriately thought of as a cycle.

Communicate Results

Evaluate and Redesign

viii

Earthquakes

Name ___________________________________ Date ___________________ STEM

4. Choose One SolutionPurpose: To decide which solution best solves the problem

Ask yourself: What are the strengths and weaknesses of each solution? Which solution is the most useful? Which solution is the least complicated?

How will I develop my solution?

3. Develop Possible SolutionsPurpose: To think of several ways to solve the problem

Ask yourself: What are different ways to solve the problem? What materials are available? How can I use the available materials?

What is my solution limited by?

2. Do ResearchPurpose: To gather information

Ask yourself: What questions do I have? What observations can I make? What solutions to the problem exist? How can they be improved? What materials are available? What is my solution limited by?

1. Identify the ProblemPurpose: To recognize a specific issue that needs to be addressed

Ask yourself: What is the challenge? What needs to be improved? What is the need?

The Design ProcessEngineers follow a process to make new products. The process begins with identifying a problem. Then engineers imagine, plan, create, and evaluate a product that addresses the problem.

Use this guide to develop solutions to problems you identify. Remember that engineers often revise prototypes many times, so you may carry out parts of the process several times when developing a solution.

ix

Earthquakes

Name ___________________________________ Date ___________________ STEM

8. Evaluate and RedesignPurpose: To consider how to improve your design

Ask yourself: Did my design work the best that it could? How could I make it better? Is it practical? Are the materials cheap and easy to

find? Does my solution create new problems, or the need for another new product? Will others be able to use it equally as well?

7. Communicate ResultsPurpose: To share your results and learn from others

Ask yourself: How should I best communicate my results? Should I make a drawing and show people my prototype?

How should I ask for others’ feedback on my design?

6. Test the PrototypePurpose: To see how well your design worked

Ask yourself: Did it work? Did it accomplish what I wanted it to do? Did anything else happen during my test that I didn’t expect?

5. Design and Construct a PrototypePurpose: To plan a design, gather materials, and build a model of your solution

Ask yourself: What materials do I need? How do I build a functional model? What are the special characteristics, or specifications, of my model?

v

Building for Earthquakes

The Design Process Identify the ProblemAt the beginning of each activity, students are asked to identify the problem that their designs will address. This step is important because it informs the rest of the design process and defines how success will be measured. The scenarios presented in the book vary. Some are true problems that need to be solved, such as how to safely filter water samples. Others focus on improving an existing design, such as building a device that allows students to flip a light switch from across the room. A handful are more conceptual in nature. For example, students would not be expected to design an actual dam and experiment with water flow to observe effects on the environment. The purpose of activities such as these is to help students understand some basic design concepts and apply those concepts to different problems or tasks.

Do ResearchAfter a problem has been identified, students conduct research. This research may include finding articles in books, magazines, or on the Internet to help students begin to formulate ideas and recognize constraints for their designs. During this stage, students examine existing designs, which can provide a starting place and help students formulate questions. Research is also the step in which students discover and explore the important elements of a design. Guided questions encourage critical thinking about aspects of the problem that must be addressed in order to develop a successful design.

In each activity, the research step includes the question, What are your design constraints? This question helps students recognize the limits of their solutions and to eliminate solutions that would be inefficient, costly, or physically impossible.

Develop Possible SolutionsNext, students brainstorm possible design solutions that address the problem they identified. Possible solutions may include variations on one design using the same or different materials. They also may include completely different designs. This step allows students to recognize the pros and cons of each design.

Choose One SolutionIn this step, students choose one of their proposed designs and describe it in detail. They may be asked to draw or diagram their design and to explain why they chose it. Having as much information as possible about each possible solution and keeping the problem or task in mind is helpful for choosing a successful design. The chosen design should represent the solution that students think best meets the need or solves the problem that was identified at the beginning of the design process.

STEM Matters

Focus on: Building for Earthquakes

Introduce the TopicTeacher Support Planner and Pacing Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi Notes and answer key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B

Student Pages Science Quick Lab: How Do Seismic Waves Travel Through Earth? . . . . . . . . . . . . . 1 Vocabulary Practice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Math Practice Ratios and Proportions: Making a Scale Diagram . . . . . . . . . . . . . . . 3 Math Practice Ratios and Proportions: Mapping Earth . . . . . . . . . . . . . . . . . . . . . . 4

Teach the TopicTeacher Support Planner and Pacing Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5A Notes and answer key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5C

Student Pages Technology: How do Seismographs Work? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 STEM Project: Shake, Rattle, and Roll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Career Spotlight: Structural Engineer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Science Inquiry Lab: Finding the Epicenter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Enrichment: Earthquake Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Evaluate the TopicTeacher Support Planner and Pacing Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18A Notes and answer key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18B

Student Pages Review and Reinforce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Assessment: Earthquakes and Seismic Waves . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Performance Assessment: Seismic-safe Buildings . . . . . . . . . . . . . . . . . . . . . . . . 20

Materials Note: Before starting any activity, consult the planner pages for a list of materials. Due to the open-ended nature of the activities in this booklet, students may choose to use materials that have not been listed. Review the activity prior to assigning to students to determine what additional materials may need to be gathered.

Introduce the Topic

EngageTo introduce the topic, invite students to discuss what they know about earthquakes. Then ask, “If you lived along a major fault like the San Andreas fault in California, what features would you want your house to have?” On the board, list student answers. (Possible answers: strong walls, steel reinforcements in the foundation, one level)

ExploreUse the Science Quick Lab How Do Seismic Waves Travel Through Earth? to introduce students to the concept of how energy travels as seismic waves through the Earth’s interior and across its surface. Review with students the properties of the three types of seismic waves: P waves, S waves, and surface waves. Materials: spring toy

:

Focus on: Building for Earthquakes How are buildings designed to withstand earthquakes?STEM OVERVIEW Students learn about earthquakes through hands-on learning and inquiry as they design, build, and test a model that simulates an earthquake and its effect on topographical features and built structures. Students begin by investigating different types of seismic wave motions. After developing an understanding of how seismic waves move, students take on a design challenge using everyday materials to build a model that simulates an earthquake. Students will:

• identify the main types of seismic waves and their properties. • identify how to locate an epicenter. • use the design process to design and build a model that simulates an earthquake

.

vi


S T E M

S T E M

S T E M

S T E M

Science Quick Lab How Do Seismic Waves Travel Through Earth?

10 min Student Page: p. 1Teacher Support: p. 1B

Vocabulary Practice 15 min Student Page: p. 2Teacher Support: p. 1B

Math Practice Ratios and Proportions: Making a Scale Diagram

15 min Student Page: p. 3Teacher Support: p.1B

Math Practice Ratios and Proportions: Problem-Solving Practice: Mapping Earth


S T E M Resource Pacing Where to Find it

S T E M

1A


:

PACING: 12-14 periods or 6-7 blocks

Have students use the Vocabulary Practice to create a personal STEM glossary. Review the example to be sure students understand the tasks. Then invite them to write or draw their own definitions, and a strategy to help them recall the meanings for each term. Additional information that relates to the term can be added as students progress. Explain that some words, such as fault, have multiple meanings. When reading, it is important to pay attention to the context in order to understand the correct meaning of the word. Have students suggest other words with multiple meanings such as law.

Review prior knowledge that students will need to understand earthquakes. Be sure stu-dents understand that: • The three main layers of Earth are the crust, the mantle, and the core. • Compression, tension, and shearing are three main types of stress. • There are three main types of faults: normal faults, reverse faults, and strike-slip faults.

Misconception Alert Address a common misconception by asking students if they have ever heard that California is going to fall into the Pacific Ocean as a result of movement along the San Andreas fault. Tell students that the San Andreas fault is a strike-slip fault, so the movement of the rocks is lateral, not up or down. They may be surprised to learn that part of California is actually moving north. This also presents an opportunity to discuss what a normal fault is. In order for California to slide into the Pacific Ocean, the San Andreas fault would have to be a normal fault. Normal faults occur where two plates diverge, or pull apart. Use your hands to model the direction of movement along a strike-slip fault and a normal fault.

Students will need to review ratios and proportions in order to create a scale model later. Use the Math Practice Ratios and Proportions: Making a Scale Diagram and Ratios and Proportions: Mapping Earth to review. Be sure students understand that: • A scale is the ratio of the measurements in a drawing to the actual measurements of the objects drawn. • In a scale drawing, distances are proportional to actual distances.Materials: metric ruler

!

S T E M

S T E M

S T E M

KEy COnCEPTS

Science Technology Engineering Mathematics

Understanding Faults and Seismic Waves

• types of stress

• types of faults

• earthquakes

• seismic waves

Seismographs

• seismograph

• seismogram

Seismic-safe Building Design

• structural engineering

Making a Scale Diagram

• ratios

• proportions

• scale

STEM Project Shake, Rattle, and Roll: Design and Test a Seismic Safe Building

Community Connection: Engineers in the Neighborhood

Intro

duce

1B


Earthquakes Teacher Page

How Do Seismic Waves Travel Through Earth? (p. 1)

Inquiry FocusObserve—using the sense of sight to gather information about the two types of seismic waves that travel through the interior of Earth during an earthquake

Group Size Pairs

Class Time 10 minutes

Procedure Tips1.Have students spread out so they have ample

room to work. Consider putting some groups in a hallway or outside to complete the activity.

2.Advise students to hold both ends of the spring securely as they make the waves.

3.If students have difficulty observing differences in the two wave types, allow them to repeat each step several times.

4.Expected Outcome: In Step 2, the coils move forward and back along the spring in a straight line. In Step 3, the coils move from side to side.

Answers1.In Step 2, the coils move forward and back

as a wave moves from the compressed end of the spring to the other end in a straight line. In Step 3, the coils move from side to side as a wave moves from the jerked end of the spring to the other end.

2.Sample Answer: Students may expect the waves in Step 2 to feel like they are being pushed and pulled, forward and back. The waves in Step 3 may feel like the side-to-side motion you get when you are riding in a car around sharp curves.

Definitions (p. 2)tension–Stress that stretches rock so that it becomes thinner in the middle.

fault–A break in Earth’s crust along which rocks move.

focus–The point beneath Earth’s surface where rock breaks under stress and causes an earthquake.

epicenter–The point on Earth’s surface directly above an earthquake’s focus.

seismic wave–Vibrations that travel through Earth carrying the energy released during an earthquake.

seismograph–A device that records ground movements caused by seismic waves as they move through Earth.

engineer–A person who uses both technological and scientific knowledge to solve practical problems.

ratio–A ratio is a comparison of two quantities by division

Ratios and Proportions: Making a Scale Diagram (p. 3)1.3 m

2.1.2 m

3.17.5 m

Ratios and Proportions: Mapping Earth (p. 4)1.33.8 km

2.6.8 km

3.No, the correct scale would be 5 cm : 100 km or 1 cm: 20 km.

4.Sample: map scale is 1 cm : 100 km, map dis-tance between cities is 8.2 cm.

Science Quick Lab Vocabulary Practice

Math Practice

1C


Earthquakes Teacher Page

take noteUse this space for ideas and notes.

Intro

duce

1


10 min

Procedure1. With a partner, experiment with the spring toy to see how

many different types of wave motions you can produce. Stretch the spring toy across the floor while your partner holds the other end. Do not overstretch. Then try making wave motions.

2. Gather together about four coils of the spring toy, and then release them at the same time. Observe the direction in which the coils move.

3. Once the coils have stopped moving, jerk one end of the toy from side to side once. Be sure your partner has a secure grip on the other end. Observe the direction in which the coils move.

Think It Over1 Describe the wave motions you observed in Steps 2 and 3.

2 Predict what the two different waves might feel like if you were standing on Earth’s surface above them.

INQUIRY FOCUS Observe

Quick Lab: How Do Seismic Waves Travel Through Earth?An earthquake results from the movement of rock beneath Earth’s surface and releases tremendous amounts of stored energy. Some of this energy travels as seismic waves through the Earth’s interior and across its surface.

Materials

spring toy

Name ________________________________________ Date _____________Class _____________

10 min

2


10 minVocabulary PracticeUse your textbook or a dictionary to define the following science, technology, engineering, and math terms in the chart below. Complete the chart by writing a strategy to help you remember the meaning of each term. One has been done for you.

Term Definition How I’m going to remember the meaning

stress A force that acts on a rock to change its shape or volume.

When I squeeze a water balloon and it changes shape, I have applied a stress.

tension

fault

focus

epicenter

seismic wave

magnitude

seismograph

engineer

ratio

Name ________________________________________ Date _____________Class _____________

15 min

3


15 min

Name ________________________________________ Date _____________Class _____________Name Class Date

Ratios and Proportions: Making a Scale DiagramA scale is the ratio of the measurements in a drawing to the actual measurements of the objects drawn. A scale diagram is a drawing made so that distances in the drawing are proportional to actual distances.

Example 1 Use the scale diagram at the right to find the actual length of the room.

Step 1 Measure the length in centimeters. The room is 5 cm long in the diagram.

Step 2 Write the ratio of the length in the drawing to the actual length .

Step 3 Write a proportion relating the ratio to the scale. Then solve for .

5 5 m, so the actual length of the room is 5 m.

Example 2 A scale in a diagram is 4 cm : 10 m. Find the actual distance if the distance in the diagram is 9 cm.

Step 1 Write a proportion. Let the actual distance be d.

Step 2 Cross-multiply. Cancel units.

10 m9 cm 5 4 cmd m

So, d 5 22.5 m.

TRY iT YouRself!

Use a centimeter ruler and the scale diagram above.

1. Find the width of the room. 2. Find the distance between the windows.

3. A scale diagram of a building is 2 cm : 10 m. What is the actual length of the building if the length in the diagram is 3.5 cm?

HOW You Will Use this Skill in Science

• Mapping Earth• Reading Maps• Building Models• Drawing Diagrams

window window

15 min

Earthquakes

3

Copyright © Pearson Education, Inc., or its affiliates. All rights reserved.

Missing type usingmissing font TK

Name Class Date

63


Math Skill and Problem-Solving Activities

A scale is the ratio of the measurements in a drawing to the actual measurements of the objects drawn. A scale diagram is a drawing made so that distances in the drawing are proportional to actual distances.



Step 2 Write the ratio of the length in the drawing to the actual length /.

5 cm/ m

Step 3 Write a proportion relating the ratio to the scale. Then solve for /.

5 cm/ m 5

1 cm1 m

/ 5 5 m, so the actual length of the room is 5 m.



10 m4 cm 5

d m9 cm


10 m 3 9 cm 5 4 cm 3 d m

10 m 3 9 cm4 cm 5 d m So, d 5 22.5 m.

TRY iT YouRself!




Skill 19: Making a Scale Diagram


Mapping Earth• Reading Maps• Building Models• Drawing Diagrams•

Scale: 1 cm : 1 m

window window

0133698556_Sec6_057-068.indd 63 1/12/10 10:56:52 AM

4


10 min

Name ________________________________________ Date _____________Class _____________Name Class Date

Ratios and Proportions: Making a Scale DiagramA scale is the ratio of the measurements in a drawing to the actual measurements of the objects drawn. A scale diagram is a drawing made so that distances in the drawing are proportional to actual distances.



Step 2 Write the ratio of the length in the drawing to the actual length .

Step 3 Write a proportion relating the ratio to the scale. Then solve for .

5 5 m, so the actual length of the room is 5 m.




10 m9 cm 5 4 cmd m

So, d 5 22.5 m.

TRY iT YouRself!





• Mapping Earth• Reading Maps• Building Models• Drawing Diagrams

window window

15 min

Earthquakes

3


Missing type usingmissing font TK

Name Class Date

64


Math Skill and Problem-Solving Activities

A map scale is a ratio that compares the distance on the map to the actual distance on Earth’s surface. For example, 1 cm : 10 km means that 1 cm on the map equals 10 km on the ground. You can also use actual distances to make a map scale.

Sample Problem: The scale on a highway map is 2 cm : 5 km. The distance between two cities is 17 cm on the map. What is the actual distance between the cities?

1. Read and Understand What information is given? (the map scale, 2 cm : 5 km, and the distance between the cities on the map, 17 cm) What are you asked to find? (the actual distance in kilometers between the cities)

2. Plan and Solve

Write the map scale as a ratio. 5 km2 cm

Let d be the actual distance.

Write a proportion. d km17 cm 5 5 km

2 cm

Cross-multiply. d km 3 2 cm 5 5 km 3 17 cm

Solve for d. Cancel units. d km 55 km 3 17 cm

2 cm d 5 42.5 km

So, the actual distance between the two cities is 43 km.

3. Look Back and Check Is the answer reasonable? (Yes, substituting d 5 42.5 km into the proportion makes the cross-products equal. The actual distance is rounded to 2 significant figures.)

TRY iT YouRself!

1. The scale on a trail map is 0.5 cm : 1 km. The straight distance between 2 huts on the trail is 16.9 cm. What is the actual distance?

2. The scale on an aerial photograph is 1 cm : 2.5 km. The length of a lake is 2.7 cm on the photograph. What is the actual length of the lake?

3. The scale on a highway map is 5 cm : 50 km. Suppose you know that the actual distance between two towns is 240 km. On the map, the distance is 12 cm. Is the scale on the map correct? Explain.

4. Suppose you are making a map of a square area. The dimensions of the actual area are 1,000 km by 1,000 km. You are drawing the map on a grid that is 10 cm by 10 cm. What scale would you use? Two cities are 820 km apart on the ground. How far apart are they on your map?

Skill 19 Problem-Solving Practice: Mapping Earth

0133698556_Sec6_057-068.indd 64 1/7/10 3:53:47 PM

Ratios and Proportions: Mapping Earth

Technology How Do Seismographs Work? 15 min Student Page: p. 5Teacher Support: p. 5C

STEM Project Shake, Rattle, and Roll 150 min4-5 periods or 2-3 blocks

Student Pages: pp. 6-9Teacher Support: pp. 5C-5E

Career Spotlight What Does a Structural Engineer Do?

10 min Student Page: p. 10Teacher Support: pp. 5E

Science Inquiry Lab Finding the Epicenter 60 min Student Pages: pp. 11-16Teacher Support: pp. 5E-5G

Enrichment Earthquake Probability 10 min Student Page: p. 17Teacher Support: p. 5G

S T E M

S T E M

S T E M

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5A


Focus on: Building for EarthquakesTeach the Topic

Explain

Before beginning to discuss seismographs, have students take out their Vocabulary Practice, so they can continue to add definitions to their STEM vocabulary. Invite students to define seismographs and have them share their definition and strategy for remembering the meaning with the class. You may want to review quickly ratios and proportions because students will be building scale models at this point. Present a quick mental math activity. Tell students that you have a scale model that is 15 cm long and 10 cm wide. The scale is 1m : 5 cm. Ask: How many meters long and wide is the real building? (3 m x 2 m)

Use Technology How Do Seismographs Work? to help students understand how technology is used to study earthquakes. Reinforce the properties of the three types of seismic waves, especially the speed in which they travel. Using the diagram on the worksheet, invite students to predict the function of a seismograph. Be sure students understand its purpose. Then ask students how this technology helps seismologists study earthquakes.

Have students work in groups on the STEM Project Shake, Rattle, and Roll. Refer to the Teacher pages on pp. 5C-5E for background information, objectives, and discussion questions.

Students will design, build, and test a model that simulates an earthquake and its effecton topographical features and structures they build. Students will determine which aspectsof an earthquake are important to demonstrate in a working model. They will also decidewhat materials to use to build their model. Using their design and materials, students will build a model. Finally, students will prepare a presentation showing how they built their prototype, how it performed, and why their results were significant.

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If needed, introduce or re-introduce the design process before you begin the STEM project. Refer to The Design Process in the STEM Program Guide.

Materials: clay, sand, soil, small rocks, cardboard and paper of varying thicknesses, fabricand vinyl squared (discarded vinyl or plastic tablecloths cut into pieces that mirror themaximum size of the models work well), toothpicks, tape, glue, craft sticks, rulers, dowelrods (cut to approximately 25 cm lengths), plastic foam, scissors, string, paper towel tubes, straws, goggles. Additional materials for making buildings could include interlocking blocks, cardboard boxes, and foam cups.

To highlight a STEM career that connects to earthquakes, have students read Career Spotlight What Does a Structural Engineer Do? Ask students to brainstorm other careers that might use knowledge of stresses, faults, scale models, and earthquakes. (for example: forensic seismologists, earthquake engineers, and architects.)

Community Connection If possible, invite a local structural engineer to share with the class a typical day or an exciting project they’ve completed. Encourage your guest speaker to bring photos and blueprints from recent projects or computer software that they use to design.

Pair students to do the Science Inquiry Lab Finding the Epicenter. Have students com-plete the pre-lab prior to starting the lab to review key content as well as how to draw conclusions and analyze data. Upon completion of the lab, have students complete the post-lab. Afterward, debrief the lab to be sure that students understand:• An earthquake occurs when rock that is under stress below Earth’s surface breaks and releases energy.• The focus is the place underground where the rock breaks.• The epicenter is the point on the Earth’s surface directly above the focus. The strength of an earthquake is greatest at its epicenter.• Seismographs record the difference in arrival time between P and S waves to determine the location of the epicenter.

Materials: drawing compass with pencil, outline map of the United States

If time allows or for students who finish early, assign the Enrichment Earthquake Prob-ability. Students will discover the likelihood of an earthquake occurring along the San Andreas fault.

Teach

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Earthquakes

Teacher PageEarthquakes

5C


Technology

Seismographs (p. 5)1. Ontheseismogram,theleftseriesofwavesarePwaves;thecenterseriesofwavesareSwaves;therightseriesofwavesareSurfacewaves.

2. Thefirstzigzags,whicharesmaller,arethePwaves,sincetheyarrivefirstandarefeltless.ThenextsetoflargerwavesclosetogetheraretheSwaves.Surfacewavesarrivenext.Theyarethelargestandslowest,sothezigzagsarebiggerbutmorespacedout.

Shake, Rattle, and Roll (p. 6-9)

Background The motion of Earth’s tectonic plates causes stress at faults. Faults are cracks or breaks in rock along which the rock can slip. When the built up stress causes a fault to shift, the rock can move suddenly. This produces seismic waves that shake the ground—an earthquake.

Earthquakes happen all the time. Most are too small to notice, but large earthquakes can produce extreme ground movement. They can open up cracks in the ground, cause land to shift, and cause severe damage to built structures.

In this activity, students will design, build, and test a model that simulates an earthquake and its effect on topographical features and built structures.

Objectives• Communicate a problem, design, and/or solution.

• Select materials for an engineering task based on their properties.

• Evaluate the effectiveness of a design solution.

Materials clay, sand, soil, small rocks, cardboard and paper of varying thicknesses, fabric and vinyl squared (discarded vinyl or plastic tablecloths cut into pieces that mirror the maximum size of the models work well), toothpicks, tape, glue, craft sticks, rulers, dowel rods (cut to approximately 25 cm lengths), plastic foam, scissors, string, paper towel tubes, straws, goggles

Optional Materials

Additional materials for making buildings could include interlocking blocks, cardboard boxes, and foam cups.

Tips• Organize students in groups of 2–4.

• Provide a heavy cardboard base for each group that dictates the maximum size of their model.

Advance Preparation• Obtain diagrams of faults and of the types of

movement of seismic waves.

• Obtain photographs of earthquake damage to land surfaces, buildings, roads, and bridges.

Safety PrecautionsStudents should wear goggles when building and testing their models.

Pre-Activity DiscussionShare the provided background information. Then use these discussion ideas to help students prepare for the activity.

Describe how building foundations are constructed. (Usually concrete footers are poured into trenches dug several feet into the ground; buildings are secured to the ground itself instead of merely resting on top).

STEM Project

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Teach

.

Then, ask:

• What causes earthquakes? (Release of energy when rock at a fault slips)

• What are some ways in which seismic waves can cause the ground to move? (Up and down, side to side, like a rolling wave)

• What effect can the movement of the ground have on the ground itself and on built structures? (The ground can crack and shift; structures can be damaged or destroyed.)

Tell students that in this activity they will design, build, and test a model that simulates an earthquake and its effect on land and buildings.

Review design constraints with students. The model:

• must fit on the provided base.

• must include a fault.

• must represent both topography and built structures.

• must simulate seismic motion.

Post-Activity Discussion Explain that it is common for engineers to modify a prototype many times before it works they way they want it to. Use these discussion ideas to help students draw conclusions about the activity.

• Have students who successfully modeled movement at a fault present their models and design plans. Discuss why these models worked.

• Ask students to share any ideas they did not get to try.

Sources• http://earthquake.usgs.gov/research/modeling/

eqmodel/Earthquake-Model.doc

• http://earthquake.usgs.gov/learn/eq101/EQ101.htm

• http://web.ics.purdue.edu/~braile/educindex/educindex.htm

• http://web.ics.purdue.edu/~braile/edumod/foammod/foammod.pdf

• http://web.ics.purdue.edu/~braile/edumod/building/building.htm

AnswersPossibleresponsesareshown.Acceptallreasonableresponses.

1. Mydesignwillmodelthemotionofanearthquakeandhowitaffectsthegroundandbuildings.Understandingaboutearthquakescanhelppeopledesignbetterbuildings.

2. Themodelshouldincludetheground,afault,landfeatures,andbuildingsofdifferentheights.

3. Aworkingmodelshouldshowafault,movementoftheground,andaneffectonbuildings.

4. RefertothePre-ActivityDiscussionforthedesignconstraintsthatstudentsshouldrecognize;studentsmayalsociteothers.

5. Likelymethodsforsimulatingmotionincludelayeringthe“land”materialonseparatecardboardsectionsthatcanslidepastoneanotherorlayeringthematerialonfabricunderwhichadowelrodcanbeslidtoproduceasurfacewave.

6–8.Studentsshoulddescribeviableusesfortheprovidedmaterials.Lookforanswersthataddresstopographicaldesign,inclusionofafault,builtstructures,andmechanismsforsimulatingseismicmotion.

9–10.Dimensionsoffeatureswillvarywithstudentdesign.Diagramshouldbedetailedenoughtoprovideameaningfulcomparisonwiththeprototypeafterthetest.

11–13. Wavemotionandtheresultsofthemotionwillvarywithstudentdesign.Diagramshouldbedetailedenoughtoprovideameaningfulcomparisonwiththediagramoftheprototypebeforethetest.

14–15. Studentsshouldkeeprecords(drawings,photographs,notes)thatdocumentthedesign,building,andtestingprocesses.Theyshouldbeabletoassociatetypesofmovementintheprototypewitheffectsonnaturalandbuiltfeatures;theyshouldinfertheeffectsofrealearthquakeactivityonlandandbuildings.

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16–18. Studentsshouldevaluatetheirprototypesagainsttheprovidedcriteriaandincomparisonwithprototypesbuiltbyothers.Theyshouldconcludefromthoseobservationshowtheycouldimproveupontheirdesigns.

Structural Engineer (p. 10)1. Answerswillvary.

2. Sampleanswers:Askinvolvesfindingoutwhatisneededorwanted;imagineinvolvesbrainstormingdifferentoptions;planinvolvesdrawingplans,createinvolvesvisitingthesite(createismostlycarriedoutbytheconstructioncrew);improvemightbelearningfromexperience.Studentsmaysaythat“plan”takesthelongestfor

thecivilengineer.

Finding the Epicenter (pp. 11-16)

Unlocking the Key ConceptThis activity will help students understand how scien-tists use data from seismographs in different locations to identify an earthquake’s epicenter.

Inquiry FocusInterpret Data—analyzing information from different seismographsDraw Conclusions—using data from different seismo-graphs to draw a conclusion about the location of an earthquake’s epicenter

Group SizePairs

Class Time60 minutes

Advance Preparation (10 minutes)1. Make photocopies of seismograms for students.

Seismograms can be obtained at www.ncedc.org. Go to Top Picks, then click on Current seis

mograms. Choose seismograms from five differ-ent cities. Before students begin the activity, give each student a copy of all five seismograms. Make sure all seismograms are derived from the same earthquake.

2. Make photocopies of the graph entitled “Difference in Seismic Wave Arrival Times” located on page 5J. Be sure you make the copies dark enough to show all lines in the graph. Before students begin the activity, give each student a copy of the graph.

Procedure Tips1. Although students are working in pairs, have each

student complete his or her own map.2. Sample Answers to Procedure Step 2:

a. We need to know the difference in arrival times of P and S waves.

b. The seismograms show the time of arrival of P and S waves. Subtracting the arrival time of the P waves from the arrival time of the S waves will give you the difference in arrival times, which can then be used to determine the distance to the epicenter.

c. We need to record the difference in arrival times for P and S waves and the distance to the epicen-ter. We will record this in a table.

d. to measure distances on the mape. Use the map scale to determine the map distance

in centimeters from the city. Set the compass on the same number of centimeters, place the com-pass point on the city, and draw a circle around the city.

3. If students have trouble with Step 2d, try asking them a series of leading questions. Ask, What does a map scale show? (the distance on the map that represents a certain number of kilometers or miles on the real land surface) What is this map’s scale? (Each centimeter on the map represents 300 km on land. If students cannot answer your question, have them lay a metric ruler along the scale line to see how many kilometers are represented by each centimeter.) Suppose that you wanted to show a distance of 1,800 km away from Denver on this map. How would you determine the length of that map measurement in centimeters? (Divide the distance you want to show by the number of kilometers repre-sented by 1 cm on the map: 1,800 km ÷ 300 km =

Science Inquiry Lab

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6 cm on the map.) Then ask, How would you use the compass to measure that distance? (Set the compass arm at 6 cm, hold the metal point on the dot for Denver, and draw a circle. To determine the compass setting, students also could hold the metal point on the 0 end of the scale line and adjust the compass arm so that the pencil point is at 1,800 km on the line.) What does the circle show? (all the points 1,800 km away from Denver) If students need more practice, give them additional examples, not including the distances they will use in the activity.

4. If the student procedure is not correct, try to avoid giving students the right answer. Instead, let them carry out the procedure and come up with an answer. Students may find they cannot get an answer and need to revise their procedure. This allows them to experience the scientific process.

Sample Data

Data Table

City Difference in P and S Wave Arrival Times

Distance to Epicenter

Denver, Colorado 2 min 40 s 1600 km

Houston, Texas 1 min 50 s 1000 km

Chicago, Illinois 1 min 10 s 650 km

The correct compass settings are 5.3 centimeters for Den-ver, 3.5 centimeters for Houston, and 2.2 centimeters for Chicago. The point on the map at which all three circles intersect will be about 600 kilometers south of Chicago. Slight variation in results may occur because students are taking measurements from a map scale and also inter-preting a graph. So, some error is to be expected.

Answers—Pre Lab1. We are given data about the difference in P and S wave arrival times and data about the relationship between the difference in arrival times and the distance to the epicenter. Data are presented in data table and graph form.

2. We will be able to determine the epicenter

Answers—Analyze and Conclude1. The intersection points represent possible epicenter locations. Any two circles will intersect with each other twice. These points represent possible epicenter locations with respect to those two seismograph centers. The actual epicenter will be at the intersection of all three circles.

2. The epicenter is located east of the Mississippi River on the border of Kentucky and Tennessee.

3. The difference will be approximately 3 minutes and 45 seconds.

4. Students may suggest obtaining data from additional seismograph centers to see if the location can be narrowed down any more. They may suggest looking for the spot where the three circles come closest to intersecting. Some students may draw lines on the diagram to try to determine an intersection point:

5. Sample Hypothesis: Because the circle does not intersect with any of the others, this circle represents all of the possible epicenter locations of a different earthquake.

Answers—Post Lab1. Errors can occur when reading the graph or drawing with the compass.

2. The P and S waves could yield the time the earthquake occurred, the difference in P and S wave arrival times, the distance to the epicenter, and the earthquake’s strength.

3. The seismogram that has the first S and P waves closer together will be closer to the epicenter.


5G


Teach

Enrichment4. Look for answers that include at least one specific statement about what the student learned. It may be a fact about finding the epicenter or a statement about the process undertaken in the lab. Answers about what students still want to know should relate, directly or indirectly, to the process of finding an epicenter.

Communicate—Student news reports should include an understanding of P waves, S waves, seismographs, and the process of determining an earthquake’s epicenter.

Monitoring Earthquakes (p. 17)1. Parkfield.2. less than 10 percent3. Slow, continual movement prevents stress from building up in the rocks; energy is released frequently in very small amounts rather than suddenly in a severe earthquake.4. The rocks on either side of the fault there probably lock together and do not move until enough stress builds up.

take noteUse this space for ideas and notes.

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How Do Seismographs Work?You have probably seen zig-zagging lines, like the ones shown below, used to represent an earthquake. The pattern of lines, called a seismogram, is the record of an earthquake’s seismic waves. It is produced by an instrument called a seismograph.

Measuring Seismic Waves When you write a sentence, the paper stays in one place while your hand moves the pen. But in a seismograph, it’s the pen that remains stationary while the paper moves. Why is this? All seismographs make use of a basic principle of physics: Whether it is moving or at rest, every object resists any change to its motion. A seismograph’s heavy weight resists motion during an earthquake. But the rest of the seismograph is anchored to the ground and vibrates when seismic waves arrive.

A simple seismograph, like the one to the right, can consist of a heavy weight attached to a frame by a spring or wire. A pen connected to the weight rests its point on a drum that can rotate. As the drum rotates, the pen in effect draws a straight line on paper wrapped tightly around the drum. Seismic waves cause a simple seismograph’s drum to vibrate, which in turn causes the pen to record the drum’s vibrations. The suspended weight with the pen attached moves very little. This allows the pen to stay in place and record the drum’s vibrations. The height of the lines drawn by the seismograph is greater for a more severe earthquake or an earthquake closer to the seismograph.

Modern seismographs are complex electronic devices. In addition to the severity of the shaking, they also record the precise timing of the shaking. Some laptop computers and car air bags contain similar devices that detect shaking.

Reading Questions

1. Reading a Seismogram Label the places on the seismogram above that show when the P waves, S waves, and surface waves arrive.

2. Understanding Earthquakes When you look at a seismogram, how can you tell when the P waves arrive? the S waves? the surface waves? ___________________________________________________________________________________

___________________________________________________________________________________

Wire

Weight

Pen

RotatingDrum

Seismograph

Groundmotion due

to seismic waves

Seismogram

Name ________________________________________ Date _____________Class _____________

15 min

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STEM Project: Shake, Rattle, and RollEarth’s surface is made up of rigid tectonic plates that rest and gradually move atop its elastic mantle. Forces from tectonic plate movement cause stress on the brittle crust at Earth’s surface. When enough stress builds up, the rocky crust breaks, forming a fault. An earthquake occurs when the stress along a fault causes the rock to slip. This movement releases energy that travels through Earth as seismic waves.

Seismic waves occur in three types. P waves compress and expand the ground like an accordion. S waves can vibrate from side to side or up and down. Surface waves can make the ground roll like ocean waves. Seismic waves can affect natural land features and structures built by people.

In this activity, you will design, build, and test a model that simulates an earthquake in order to learn how earthquake energy affects land and buildings.

Identify the Problem 1. Suppose you are an architect who designs homes in a fault zone. Why would learning about

earthquakes be important to you?

Do ResearchExamine the diagrams of faults and seismic waves.

2. What physical features should be visible in an earthquake model?

3. Which aspects of an earthquake are important to demonstrate in a working model? Explain.

150 min

Name ________________________________________ Date _____________Class _____________

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STEM Project: Shake, Rattle, and Roll continued

Go to the materials station(s). Examine the materials. Think about which materials may be useful for your model. Leave the materials where they are.

4. What are your design constraints?

Develop Possible Solutions

5. Describe ways in which you could use the materials to build a model of Earth’s surface at a fault. Identify at least two ways you could simulate earthquake motion in your model.

Choose One Solution

Answer the following questions on a separate sheet of paper.

6. List the material(s) you will use for your earthquake model.

7. Draw your design and label all the parts. Describe how you will build your earthquake model.

8. Describe how your model will simulate the motion of an earthquake.

Name ________________________________________ Date _____________Class _____________

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Design and Construct a PrototypeHave your teacher review and approve your design. Then, gather the materials you need to build your earthquake model. The structure you build will be your prototype, the first working version of your design. If you can, document your construction process by taking photos or recording video as you go. Be sure to wear goggles as you build and then test your prototype.

9. Measure the dimensions of your prototype. Record the design details.

10. On a separate piece of paper, draw a detailed diagram of your prototype. Label the features and measurements.

Test the PrototypeTest your prototype. Use whatever method you have developed to simulate the motion of an earthquake. Observe what effects the motion has on the land features and the built structures you included in your prototype.

11. Circle the wave motions your prototype simulated.

P wave motion S wave motion Surface wave motion

12. How did your simulated earthquake motion affect the land and buildings on your prototype?

13. On a separate piece of paper, draw in detail what your prototype looks like after the test.

Name ________________________________________ Date _____________Class _____________

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STEM Project: Shake, Rattle, and Roll continued

Communicate Results 14. Collect the materials that document the design, construction, and testing of your prototype.

Assemble a portfolio that includes the before and after diagrams of land area, your photographs of the process, and a record of your test results. Prepare a data table to display information about the duration and type of movement and the results in your prototype. Write a short summary of how data like yours could be useful to an architect trying to design safer homes.

15. Prepare a computer slide show or a video presentation showing how you built your prototype, how it performed, and why your results were significant. Include your conclusions on how the earthquake motion would affect natural features and built structures near the fault. Deliver the presentation to your class.

Evaluate and Redesign 16. Evaluate your prototype using the following rubric. Check one answer for each question.

Does the prototype… Very Much Somewhat Not At Allfit onto the provided base?include a representation of a fault?represent natural land features?represent built structures?show the effects of the earthquake motion?

17. Compare your results with your classmates. Did your prototypes function in similar ways? Explain.

18. What changes could you make to your earthquake prototype to make it a more accurate representation of how earthquakes affect land and buildings?

Name ________________________________________ Date _____________Class _____________

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Career Spotlight: Structural EngineerCivil engineers design things in your community such as roads, water treatment facilities, buildings, airports, and train stations.

A structural engineer is a civil engineer who specializes in the design of safe structures. Structural engineers design bridges, tunnels, freeway interchanges, high rise buildings, shopping malls, and other large-scale structures that pose special challenges. They need to design safe structures that can withstand forces such as gravity, wind, soil movement, and earthquakes.

Depending on their use, structures need to be sturdy enough to hold the weight of such things as people, cars, machinery, and of course their own weight. Structural engineers know a great deal about the strengths and properties of different materials such as steel, concrete, and wood. They also understand the physics of forces and motion.

Since structures are built on soil, the design of a building also requires knowledge of the soil it is built on. If the soil is unstable, the foundation needs to be designed to create stability, and the soil may need to be compacted, excavated, or reinforced before construction begins. If a structure is located in an earthquake zone, the building and its foundation need to be built to withstand theshaking motion of an earthquake.

Structural engineers often working in teams to design a structure and create plans and drawings for all the necessary components. Plans include scale drawing and measurements for all structural components. Plans are carefully reviewed and approved by experienced structural engineers at the city’s building department before construction begins. During construction, the structural engineer visits the site to check that plans are being carried out correctly and to advise on unexpected problems that come up. The structural engineer meets with the construction manager and signs off on the project at various stages.

Reading Questions1. Draw Conclusions Describe in your own words what a structural engineer does. Name three things in your town that were probably designed by structural engineers.___________________________________________________________________________________

___________________________________________________________________________________

2. Application How does a structural engineer apply each step of the engineering design process: ask, imagine, plan, create, improve? Which step do you think takes the longest? Why?

___________________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________

10 min

Name ________________________________________ Date _____________Class _____________

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Inquiry Lab: Finding the EpicenterReviewing Content

An earthquake occurs when rock that is under stress below Earth’s surface breaks and releases energy. The focus is the place underground where the rock breaks. Seismic waves move out from the focus in all directions, carrying energy.

The epicenter is the point on Earth’s surface directly above the focus. The strength of an earthquake is greatest at its epicenter, and this is typically where the most damage occurs.

Scientists can use data from seismographs to determine the location of the epicenter. A seismograph records both P and S waves as they arrive at the seismograph location. While P and S waves start out at exactly the same time when an earthquake occurs, P waves travel faster and reach the seismograph first. S waves arrive second. Scientists can use these data (recorded on a seismogram) to measure the difference in arrival time between P and S waves. The farther apart the arrival times of the waves are, the father the location is from the epicenter.

Reviewing Inquiry Focus

Scientists interpret data so they can draw conclusions about their hypotheses. Interpreting data means to make sense out of the data gathered during an experiment by looking at patterns or trends. Data can be displayed in different ways. A data table is an organized way to record observations from an experiment. A graph is another way to organize data. Graphs can be better than data tables for illustrating pat-terns and trends in the data.

1 In this Lab Investigation, what data are you given to analyze? In what formats are the data presented?

2 What conclusion will you be able to draw after analyzing the data?

Chicago

Savannah

Houston

EarthquakeSeismographicstation

mgs11a02566Jan Van Aarsen12/22/08

FPO

60 min

Name ________________________________________ Date _____________Class _____________

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Inquiry Lab: Finding the EpicenterThe graph shows how the difference in arrival time between P waves and S waves is related to the distance from the epicenter of the earthquake. Find the difference in arrival time for Denver on the y-axis of the graph.

Follow this line across to the point at which it crosses the curve. To find the distance to the epicenter, read down from this point to the x-axis of the graph.

Difference in Seismic Wave Arrival Times

Diff

eren

ces

in A

rriv

al T

ime

of

P a

nd S

Wav

es (m

in)

Distance to Epicenter (km)1,000 2,000 3,000

4

3

2

1

Name ________________________________________ Date _____________Class _____________

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Inquiry Lab: Finding the Epicenter

Materials

INQUIRY FOCUS Interpret Data, Draw Conclusions

Design an Experiment1. Suppose you are a seismologist and have just found out about

a major earthquake that has taken place in the United States. It is your job to locate the epicenter of the earthquake so that the Federal Emergency Management Agency (FEMA) will know where to focus its disaster relief. You have the following infor-mation and tools available:

• seismograms from five seismograph centers

• a graph showing the relationship between difference in seismic wave arrival times and distance to the epicenter

• a scale map of the United States

• a compass with pencil

2. Consider the following questions as you develop a plan to find the epicenter:

a. What information do you need to know about the arrival of P and S waves at each seismograph center?

b. How can you use the information on the seismograms to determine the arrival times? How will this information help you to determine the dis-tance of a city from the epicenter?

c. What data will you need to record? How will you record it?

d. How will you use the map scale?

e. Once you have determined how far a city is from the epi-center, how can you show all the possible points where the earthquake could have occurred with respect to that city? For example, if an earthquake occurred 100 km from a certain city, it could be 100 km north, 100 km northwest,100 km east, etc.

f. How might using data from more than one city narrow the possibilities for the epicenter location?

ProblemHow can you locate an earthquake’s epicenter?

drawing compass with pencil

Name ________________________________________ Date _____________Class _____________

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3. Write out your step-by-step procedure for finding the epicenter. Draw any data tables you will need. Have your teacher approve your plan.

4. Carry out your procedure and record your data.

Procedure

Data Table

finding the epicenter continued

ChicagoSan Francisco

Denver

Houston

Kilometers

0 300 600 900 1200 1500

Name ________________________________________ Date _____________Class _____________

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finding the epicenter continued

Analyze and Conclude 1 Interpret Data Look at the circles you have drawn on the map. There

should be various points of intersection. What do these points represent?

2 Observe Where is the epicenter of the earthquake?

3 Calculate Mark a point on the map that is 2,400 km from the epicenter, in any direction you wish. What would you expect the difference in arrival time between P and S waves to be at this point?

4 Draw Conclusions Suppose that the three circles you draw to determine an epicenter do not intersect exactly at one point. The diagram on the right shows this type of situation. Suggest a strategy for determining the epicenter.

5 Develop a Hypothesis Imagine you are given a new set of seismograms from five different locations. You follow the same procedure you carried out in this lab investigation to determine the location of the epicenter. However, as you draw circles with your compass, you find that one circle does not intersect any of the others. Develop a hypothesis to explain this outlying circle.

Name ________________________________________ Date _____________Class _____________

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Name ________________________________________ Date _____________Class _____________

Inquiry Lab: Finding the Epicenter1 Design an Experiment What sources of error might be encoun-

tered in this activity that might affect the results?

2 Predict Suppose an earthquake struck California, and its epicenter was 100 km north of San Francisco. Predict three pieces of data you could obtain from the P and S waves from this earthquake.

3 Observe Imagine you have two seismograms from different cities. How could you determine which city is closer to the epicenter simply by looking at the seismograms?

4 Summarize Describe what you learned in this lab about finding the epicenter of an earthquake and what questions you still have.

What I learned

What I still want to know

Relate Evidence and Explanation Join forces with another lab group. Your task is to create a short television news report that explains how you determined the epi-center of the earthquake. Your news report should include• an explanation of a seismograph and what it detects;• an explanation of P and S waves;• an explanation of the procedure you took in this lab to determine the epicenter;• the use of specific examples in your explanations.

Communicate

.

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Enrichment: Monitoring Earthquakes

Earthquake ProbabilityThis combined map and bar graph shows the probability of earthquakes in different areas along the San Andreas fault. Probability is a measure of how likely it is that some event will happen in a given time. A probability near 100 percent means that an event in very likely to happen. A probability near zero percent means that an event is very unlikely to happen.

1. Which area has the highest probability of an earthquake?

2. What is the probability of an earthquake in the North Coast area?

3. The fault section between the Santa Cruz Mountains and Parkfield has a very low probability. Geologists know that this area has experienced very little damaging seismic activity in the past. They also found that the blocks of rock in this section move slowly and continually. Why would slow, continual movement lead geologists to give the section a low probability?

4. What can you infer about why the probability of an earthquake is so high in the Parkfield area?

Lesson Quiz

Read the passage and look at the diagram. Then answer the questions.

Name ________________________________________ Date _____________Class _____________

10 min

San AndreasFault

Section ofvery lowprobability

Carrizo

Cholame

Parkfield90%

30%

30%

30%

10%

20%

20%

40%

Mojave SanBernadinoMountains

South Santa Cruz Mountains

San FranciscoNorthCoast

Lessthan10%

CoachellaValley

Los Angeles

Earthquake Probability Along the San Andreas Fault

San Francisco

.

18A


Focus on: Building for EarthquakesEvaluate the Topic

Review and Reinforce 30 min Student Page: p. 18Teacher Support: p. 18B

Assessment Earthquakes and Seismic Waves


Performance AssessmentSeismic-safe Buildings

135 min 3-4 periods or 1 1/2-2 blocks

Student Page: p. 20Teacher Support: p. 18B

S T E M

S T E M

S T E M


EvaluateReview what students have learned about science, mathematics, engineering design, and technology in relation to earthquakes. Ask students to share something they have learned, and write their answers on the board in a graphic organizer. Invite students to copy the graphic organizer in their notebooks.

Pair students and have them complete the Review and Reinforce. Circulate and listen to pairs as they discuss the answers to the review questions. Go over questions and answers as needed.

To assess students’ understanding of the concepts covered in this booklet, use the Assessment Earthquakes and Seismic Waves or the Performance Assessment Seismic-safe Buildings.

How are buildings designed to withstand earthquakes?

Assess students’ understanding of earthquakes, scale models, and the design process with the Performance Assessment Seismic-safe Buildings. Discuss the features of a building that might help it withstand the powerful effects of an earthquake. Ask students how those specialized building features are an example of technology. Then have students demonstrate their understanding of science, technology, engineering, and math as they build a scale model of a seismic safe building. Have students refer to the Math Practice Ratios and Proportions: Making a Scale Diagram and Ratios and Proportions: Mapping Earth on pp. 3-4 if they have difficulty calculating a proper scale for their model.

Materials: cardboard, craft sticks, modeling clay. Students may also choose to use additional resources at the teachers discretion.

S T E M

S T E M

S T E M

18B


(p. 18)

1. SeismicwavesarevibrationsthattravelthroughEarth,carryingtheenergyreleasedduringanearthquake.

2. Pwaves,Swaves,surfacewaves

3. surfacewaves

4. GeologistsmeasurethedifferencebetweenthearrivaltimesofPwavesandSwavesatthreeormoreseismographs.Usingthesedifferences,theydeterminethedistanceoftheepicenterfromeachseismographandplotthedistancesascirclesonamap.Theepicenterislocatedwherethethreecirclesintersect.

5.Sample:Ascalemodelisamodelsimilartotheactualobjectitrepresents.Thescaleofamodelistheratioofthelengthofthemodeltothecorrespondinglengthoftheactualobject.

6.Sample:Engineersshouldconsiderhowoftenearthquakesoccurinthatarea,whatthemagnitudeoftheearthquakesgenerallyare,andwhattypeoffaultlineisinthearea.

7. b

8. c

9.a

Earthquakes and Seismic Waves (p.19)

1. true

2. stronger

3. true

4. focus

5. motion

6. structural

7. 40.3cm

8. Sample:BuildingcodesinJakartalikelyrequireextraprotectionagainstearthquakedamage.ThisisnecessaryinJakartabecausethecityliesnearaplateboundaryneartheRingofFire.Itisthereforeanareaofhighriskforearthquakes.

Seismic-safe Buildings (p. 20)

A completed project should include:

• A completed model of a building

• Two of the technologies (tension ties, cross braces, base isolators, dampers) correctly applied

• A mostly accurate scale drawing with the scale correctly noted

An outstanding project might include:

• A well-constructed model of a building that is plumb and level

• More than two of the technologies correctly applied

• A detailed and neat scale drawing with the scale correctly noted

Review and Reinforce


Assessment

Performance Assessment

Evalu

ate

18


Review and Reinforce

1. What are seismic waves?

2. In what order do the three types of seismic waves arrive at a seismograph?_

3. Which type of seismic wave produces the most severe ground movement?

4. How do geologists locate the epicenter of an earthquake?

______________________________________________________________

5. What does it mean if something is a scale model?_____________________________

6. What factors do you think structural engineers need to take into consideration when building a structure in an earthquake zone?

Understanding Main IdeasAnswer the following questions in the spaces provided.

30 min

Name ________________________________________ Date _____________Class _____________

Building VocabularyMatch each term with its definition by writing the letter of the correct definition in the right column on the line beside the term in the left column.

7. focus a. slowest seismic waves 8. epicenter b. the point beneath Earth’s surface at which rock

under stress breaks and triggers an earthquake 9. surface waves c. the point on the surface directly above the point at

which an earthquake occurs

19


Assessment: Earthquakes and Seismic Waves

If the statement is true, write true. If the statement is false, change the underlined word or words to make the statement true.

1. The shaking and trembling that results from movement of rock beneath Earth’s surface is called an earthquake.

2. On a seismogram, higher lines drawn in the paper indicate weaker seismic waves.

3. P waves can become surface waves when they reach Earth’s surface.

Fill in the blank to complete each statement.

4. The of an earthquake is the point where rock under stress begins to break or move.

5. The weight and pen of a seismograph resist during an earthquake.

6. A engineer is a civil engineer who specializes in the design of safe structures.

7. You want to make a scale model of a sailboat that is 16 m long and 15 m tall. You plan to make the model 43 cm long. What is the height of the

model?

How are buildings designed to withstand earthquakes?

8. An architect is hired to design a skyscraper in the Indonesian city of Jakarta, which is near the Ring of Fire, an active earthquake and volcano zone. The architect must follow special building codes that the city has written. What might those codes be for and why are they important in Jakarta?

20 min

Name ________________________________________ Date _____________Class _____________

20


Tension tie

Steelframe

Tension tie

Steelframe

Column

Rubber andsteel layers

Foundation

Column

Rubber and steel layers

Foundation

Performance Assessment: Seismic Safe BuildingsSuppose you are on the highest floor of a tall building in your town. An earthquake strikes. What features might help the building withstand the powerful effects of an earth-quake? Civil engineers use different technologies to design buildings that can withstand earthquakes.Seismic-safe buildings have features that reduce earthquake damage. Some of these fea-tures strengthen a building. Others allow the building to move, or shield the building from the energy of seismic waves. In earthquake-prone areas, most tall, steel-frame buildings may have one or more of the seismic-safe features described here.To prevent cracks, tension ties are used to firmly “tie” the floors and ceilings of the building to the walls. Tension ties absorb and scatter earthquake energy and thus reduce damage.Base isolation is another technology. In this type of design, the building is built on rubber pads or rollers. These structures separate, or isolate, the building from its foundation. The pads, like the ones shown to the right, stop some of an earthquake's energy from entering the building. When the earth shakes, the rollers allow the building to glide on top. Cross braces form a network of steel on the outside of the building to stiffen its frame. They also absorb energy during an earthquake.Dampers are heavy weights placed on certain floors of a high rise building. Dampers work like shock absorbers in a car, absorbing some of the energy of seismic waves.

Design It

1. Modeling Seismic Safe Design Use cardboard, craft sticks, modeling clay, and other common materials to build a small-scale prototype of a seismic-safe building. Use at least two features from the list above.

2. Scale Drawings On the back of this sheet, make a scale drawing of your building prototype with labels showing the seismic features. Decide on a scale for your draw-ing. (For example, you might decide that 2 cm in your prototype will be represented by 1cm in your drawing, so your drawing will be half as wide, long, and tall as your actual prototype. Your scale will be 2 cm : 1cm.) Use a ruler to make your drawing neat and accurate, and write the scale at the bottom of your drawing.

3. Testing Place your building prototype on a table, and drop a heavy book next to it. Then try bumping the table to shake the prototype sideways in different directions. How well does your prototype stand up? What changes could you make to improve your structure’s stability?

_________________________________________________________________________________

_________________________________________________________________________________

Tension Tie

135 min

Name ________________________________________ Date _____________Class _____________

Base Isolator


21

Earthquakes

My Scale Drawing

= 1cm

21


stem

Documents

step design process

light technology

result of technology

effective technology

basis of technology

engineers design materials

new products

mathematics concepts