Unlocking the Mysteries of Plate Tectonics

Deena Bollinger

South Orangetown Middle School

Notes for the teacher:

Pre-Assessment: Before asking students to begin this investigation, have them complete a Pre-Assessment to get them thinking about the topic.  This can be done orally by having students share everything they know about earthquakes and volcanoes in a brainstorming session (full class or small group), or more formally in writing (an example is provided).  You, your students, or both should keep a record of this pre-assessment.

Skills Review:

The first task in this investigation is for students to use latitude and longitude to plot locations on a world map.  It is a good idea to remind students how to orient themselves on a map, and to review the use of latitude and longitude to locate positions on a map.  This is very challenging for many students, so they should all be encouraged to use pencil!

A nice way to help students orient themselves on a map is to first have them locate the United States, Atlantic Ocean, and Pacific Ocean.  They should remember that we live in the Western and Northern hemispheres.  Next, have students darken the 180 and 0 degree lines that go north-south, as well as the equator.  Students should now be able to indicate which areas of the map would be considered north/south latitude, and east/west longitude.  You can help them with this by having them label the part of the map to the left of the 180 line E(ast), label the part of the map between 180 and 0 W(est), and the part of the map to the right of the 0 line E(ast) again.  Have students do this along the top and bottom of the map.  Then label the left and right sides with N(orth) and S(outh) above and below the equator.  Doing this on an oversized map or large screen while students do this at their seats is often helpful.

            Do a few practice plots with students, but even after this, weaker students may still have problems plotting correctly.  You may want to plot the points yourself first so you can tell if a student is plotting incorrectly at a glance.  Locations only need to be plotted to the nearest whole number.

This investigation was inspired by:

Osmun, Vorwald, Wegner. Explorations in Earth Science. United Publishing Company Inc. Albany: 2001.

Pre-Assessment/Post-Assessment:  Have students answer the questions below both before and after completing the following investigation.

1. Are earthquakes, volcanoes, and mountain ranges related?  If so, how?

2. Are there usually warnings before a large volcanic eruption?  If so, what are they?

3. Are they usually warnings before a large earthquake?  If so, what are they?

4. Can earthquakes occur under water?  In the middle of a continent?

5. Can volcanoes occur under water?  In the middle of a continent?

6. Can more than one earthquake occur in the same place?

7. Can a volcano that has stopped erupting ever erupt again?

8. What do you think causes earthquakes and volcanoes?

Name ____________________________                                              Date ___________

Unlocking the Mysteries of Plate Tectonics

Objective: Mysteries to Solve by the end of this exploration lab

• How are earthquakes, volcanoes, mountain ranges, and plate boundaries related?
• What are the types of plate boundaries?
• What does movement at these boundaries look like?
• What are the causes and effects of these movements?
• How can we use the Tectonic Plates map on p. 5 of the Earth Science Reference Tables, and the Inferred Properties of the Earth’s Interior chart, on p.10 of the Earth Science Reference Tables to help us understand motions at earth’s surface?

Materials:

• This learning packet
• World Map with latitude and longitude marked, showing major continents and oceans
• Internet access, or printouts of data related to recent earthquakes and volcanic eruptions
• World map(s) showing major mountain ranges
• Earth Science Reference Tables (ESRT) – pages 5 and 10
• Textbook and/or dictionary
• Your mind – Yes, you must use it to solve the mysteries!

Procedure:

THIS ENTIRE INVESTIGATION MUST BE DONE IN PENCIL!  Follow the steps below.

I. Patterns of Crustal Activity

On the map provided…

1. Plot any 14 Recent Earthquakes using dots (·) and label each dot with its

            number.  Use data from: http://neic.usgs.gov/neis/bulletin/  Have you teacher

            check your first few plots.

2. Plot any 8 Recent Volcanoes using triangles (5) and label each triangle with

            its number.  Use data from: http://www.volcano.si.edu/gvp/reports/usgs/index.cfm      As you plot locations, scan the information given about each volcano listed in the

            report, as well.

3. Use maps, globes, atlases, or other resources to plot the mountain ranges listed below, with ‘carrots’ (Ù Ù).       Your ‘carrots’ should trace the path of the entire mountain range in a single file.

                        Rockies, Andes, Appalachians, Alps, Himalayas, Atlas, Hawaiian Ridge,                               Mid-Atlantic Ridge, and East Africa Rift Valley

4. Plot the following significant volcanoes using triangles (5)

5. Plot the following historic earthquakes:

6. Use the map you have created to answer the following questions in complete sentences.

            a. What have you noticed about the locations where earthquakes have occurred?

            b. How are the locations of earthquakes, volcanoes, and mountain ranges      related?

            c. What regions of North and South America show the greatest amount of crustal       activity (earthquakes, volcanoes, and mountain ranges)?

            d. According to your map, what is the probability of having a major earthquake or      volcanic eruption where you live?  Explain your reasoning.

            e. Why do you think the perimeter of the Pacific Ocean is called the “Ring of   Fire”?

II. Causes and Effects of Volcanic Eruptions

Now that you have plotted the locations of several volcanoes, carefully read the information about each of the recent eruptions provided at http://www.volcano.si.edu/gvp/reports/usgs/index.cfm and use it to answer the questions below.  Be specific.

1.      What are the warning signs for a volcanic eruption?

2.      What are some results of volcanic eruptions?

3.      What materials can erupt from a volcano?

4.      Describe the relationship between earthquakes and volcanoes.

III. Addressing Misconceptions about Earthquakes and Volcanoes

Now look at the map you created, and answer the following questions:

            True or False?

1.      Earthquakes can occur under water.  ___________

2.      Earthquakes cannot occur in the middle of a continent.  ________

3.      More than one earthquake can happen in the same place. ________

4.      A volcano that has stopped erupting can never erupt again. _________

IV. Relationship between Crustal Activity and Plate Boundaries

Compare the map you created to the Tectonic Plates map on p. 5 of your ESRT.  Answer the following questions in complete sentences.

1.      How are the locations of volcanoes, earthquakes, and mountain ranges related to plate boundaries?

2.      What do you think causes earthquakes and volcanoes?

V. Types of Plate Boundaries

1. Use the KEY on the bottom of the Tectonic Plates map, p. 5 of your ESRT, to help you define the following words.  If needed, use your textbook to help you.

            a. Plate boundary –

            b. Divergent plate boundary –

            c. Convergent plate boundary -

            d. Subduction –

            e. Transform plate boundary –

2. Use a world map to describe the location of the Andes Mountains.

3. Use the Tectonic Plates map, p. 5 of your ESRT, to place an X in the appropriate box below to identify each location as a specific type of plate boundary:

                                    Type of Plate Boundary

4. Based on the chart you have just completed, answer the questions below:

            a. Name the three types of plate boundaries, and describe the motion associated

            with each type.

b. There are three types of forces that affect earth’s crust:

1. Tension force pulls pieces of the crust apart (ß à)

2. Compression force pushes pieces of the crust together (à ß)

3. Shearing force rubs pieces of crust horizontally against each other

5. Based on the information above, and the Tectonic Plates map, complete the chart below:

VI. Additional Vocabulary

Use the knowledge you have constructed during this investigation, along with the Tectonic Plates map to describe the motion you would observe in the following locations:

1.      Trench –

2.      Mid-Ocean ridge –

3.      Rift valley –

4.      Andes mountains - a volcanic mountain range on the west coast of South America formed by subduction –

VII. Earth’s Layers

1. Do you remember Earth’s layers?  Draw a sketch below showing Earth’s crust, inner core, mantle, and outer core.  Label each layer.  Use your text or the Inferred Properties of Earth’s Interior chart on p. 10 of your ESRT if you forgot.

2. Add dotted lines indicating the bottom of the lithosphere and the bottom of the asthenosphere to your sketch above.

3. The Theory of Plate Tectonics explains that the “solid” lithosphere consists of a series of plates that “float” on the partially molten section of the mantle (the asthenosphere).  Convection cells within the mantle may be the driving force for the movement of the plates.  Plate motions and convection currents can be modeled and studied in our classroom.

            a. Does this theory make sense to you?

            b. What would you like to ask the scientists who came up with this theory? (What

            evidence or explanation would you like to hear?)

VIII. Earthquakes and Subduction Zones:

Look at the top left of the Inferred Properties of Earth’s Interior chart on p. 10 of your ESRT.  Continental crust is found underneath the continents, while oceanic crust is found underneath the oceans.

1. How dense is continental crust? (include units) ______________

2. How dense is oceanic crust? (include units) _______________

3. Which is denser – continental crust or oceanic crust? ___________________

4. Based on density, when a continental plate floating on the asthenosphere collides with an oceanic plate floating on the asthenosphere what do you think will happen?

5. What is the process described in your answer to #4 called? ______________

IX. Conclusion:

1. Which of the mysteries of Plate Tectonics have you solved?

2. Which of the mysteries of Plate Tectonics would you like to explore further?

X. Optional Extensions

1. Research one or more of the significant volcanoes or historic earthquakes listed in this lab.  Find out more about when and where these events happened, report on the destruction, any warnings ahead of time, and the recovery effort afterward.  Share the results of your research with the class by creating a poster, PowerPoint presentation, web page, or oral presentation.  List your sources.

2. Research ways in which people (scientists and non-scientists) have attempted to predict earthquakes and/or volcanic eruptions in the past.  Report on the degree of success with various methods.  Find out about current efforts to predict these destructive events, as well.  Share the results of your research with the class by creating a poster, PowerPoint presentation, web page, or oral presentation.  List your sources.

3. Research methods for making structures more earthquake resistant.  Report on one or more of these methods by creating a poster, PowerPoint presentation, web page, or oral presentation.  Or, you can create a model of one of these earthquake resistant structures, and demonstrate how it is able to withstand the shaking of an earthquake.  List your sources.

4. Design an earthquake safety pamphlet, presentation, newscast, commercial, or poster.  This could be directed at children or adults.  List your sources.