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ParkWise > Teachers > Nature > Glaciers Of Kenai Fjords > Unit Outline

Activity 1:
Glacial Impact:
What Does It Look Like?

Students will explore the relationship between glaciers and Earth's geophysical and biological systems.

Note: Activity 1 has four parts. Part 1 is "Exploring Geophysical and Climate Changes During Periods of Glaciation"; Part 2 is "Modeling the Effect of Glaciers on Climate"; Part 3 is "Modeling the Effect of Glaciers on Sea Level"; and, Part 4 is "How Might the Interaction Between Global Warming and Glaciers Affect Life on Earth?"

Instructional Resources:
Please see the Kenai Fjords Instructional Resources Page.

Part 1: Exploring Geophysical and Climate Changes During Periods of Glaciation

Before beginning the lesson, gather together the following materials and equipment:

1. Gather together media center resources and world maps.
2. Make Internet access available
3. Make copies of Student Resource: Glacial Ice

Procedures:

1. Begin the activity by asking students the following questions:
   1. What is a glacier? Where are glaciers found?
      ANSWER: A glacier is an accumulation of ice, air, water, and rock debris or sediment.
   2. How do they form? How long do they last?
      ANSWER: Glacial ice is the product of a decades-long, or even centuries-long, process that compresses fluffy white snowflakes, or clear spicules of frozen precipitation, into very dense crystals. This precipitation lies on top of, and compresses, precipitation that fell from the sky in previous years. Depending upon the size of the glacier, it can last hundreds, thousands, even billions of years long, advancing and receding as global temperatures fluctuate.
   3. What global climate factors affect glaciation?
      ANSWER: Glaciers can be found anywhere when the snows and frozen precipitation of long, cold winters are not completely melted during the short, mild summers. What controls the glaciation is not how much snow falls during the winter, but how much ice remains after the seasonal melting.
   4. How have patterns of glaciation changed over Earth's history? How do we know?
      ANSWER: Over the last 1 billion years, large parts of the planet were covered by glacial ice that has advanced and shrunk in cyclic periods. In fact, in the last 1.5 million years, there have been at least 20 cycles during which Earth's ice sheets have grown to twice the size they are today and then shrunk back, depending upon global average temperatures. Large or small, glaciers leave abundant evidence of their presence, even after they have melted and the ice has disappeared. Their imprints are everywhere: the spires, or horns, of mountains such as the Matterhorn; the Great Lakes of North America; and, the boulder fields of New England. Glaciers erode the landscape, carving valleys and small lakes, wearing away rock, and stripping soil from the ground. They also add to the landscape by depositing materials from huge boulders to piles of rock and other debris dragged along as the glacier flows downhill.
2. Distribute the Student Resource: Glacial Ice. Have students read the information and discuss the ideas. Encourage each student to develop questions concerning the cyclic nature of global glaciation -- past, present and future.
3. Allow enough time for students to use the resources available from the National Park Service that detail the changes in glaciers found in Kenai Fjords National Park Home and Kenai Fjords National Park Information, as well as evidence of past glaciation in these areas. Also, have the students access some or all of the Internet resources listed at the end of the Student Resource: Glacial Ice.
4. Distribute copies of world maps to students and instruct them to use references to show the areas of major glaciation today.
   1. Challenge students to label the glaciers by type, e.g., alpine, continental, tidewater, etc.
   2. Ask students if the glaciers are retreating or advancing.
      Have them use color-coding or another legend to indicate the different types of glaciers. (Map of the World: Continents )
      ANSWERS: The answers depend on students' research from the Information Sources.
5. Divide the class into several groups and assign each group a geological time period. Groups should use their world maps to show the patterns of global glacial change during their assigned time period. Teachers could choose vast periods of time (e.g., from 800 million years before the present - see Fundamentals of Physical Geography) or the latest period of extensive glaciation from 115,000 year ago to the present. (See Ice Age: Park and Trail Foundation).
   ANSWERS: The answers depend on students' research from the Information Sources.
   Note: Links given in the Information Sources are excellent starting points for this research. However, more must be done to complete the maps accurately. Most likely, students will discover that scientists disagree about these patterns of change.
6. With each completed map, have students state scientific theories that support the causes of glaciation during the particular time frame investigated. Encourage students to question existing theories and either support the theory they believe is most accurate or generate a viable alternative.
   Note: The following resources are especially helpful with this question:
   • A brief introduction to Ice Age theories
   • Why were there four long, generally cool periods during which continent- sized glaciers advanced and retreated?
7. Finally, have students use the reference materials ? particularly those from photographs and eyewitness accounts of recent changes in glaciation -- to predict global glaciation in the next few decades or centuries. Students should show their predictions on a map. Challenge them to give scientifically valid reasons for their suppositions.
   ANSWER: Answers will vary.
8. Conduct a "Glaciation Symposium" in which each group reports its findings and predictions. Invite other classes to attend the symposium and question the "experts."

Extension: Exploring Geophysical and Biological Changes (Recommended for older high school students)

1. Have students use a variety of resources to find information dealing with different aspects of the Activity topic. Divide the following questions among 5 groups of students to research.
   1. What geologic features are associated with glaciers? How do we know? Do these provide evidence that glaciers change? Explain.
   2. What ecosystems are found near glaciers? Are these environments similar in all areas of glaciation? Explain.
   3. What are "remnant populations"? How do these provide evidence of past glacial activity?
   4. How do ice and ocean cores provide evidence of past climates? How can spores, seeds, arthropods, dust particles and trapped air bubbles be used to map the past?
   5. What historical records provide information about climate and glaciers? What pre-historical evidence gives clues to past climates?
2. Use some of the following topics to direct students' Internet research:
   • Climate Patterns and Changes
   • Ice Coring
   • Ocean Sediment Coring
   • Historical Accounts
   • Little Ice Age
   • Remnant Populations
   • Prehistoric Anthropological Evidence
   • Floral and Faunal Changes
3. The following sites will be helpful starting points for student research. However, students should expect to use local resources from libraries and nearby colleges to extend their research.
   • Kenai Fjords National Park Information
   • Glaciation
   • A Paleo Perspective on Global Warming (NOAA)
   • Palaeoclimatic Change Study Guide
   • Little Ice Age a Global Event
4. Using this information, groups should present their findings to the class.
5. Students can share this information in the Global Symposium (see above), and/or use their research in a class debate on the following statement: The evidence used to prove the presence of glaciation in Earth's history could just as easily be used to prove the occurrence of an Earth-wide flood.

Part 2: Modeling the Effect of Glaciers on Climate

Before beginning the lesson, gather together the following materials and equipment:

1. 3-to 5-gallon aquariums with tops
2. Sand, dirt, rocks
3. Small plants, flowers or very small branches
4. Small toy houses, cars, people, etc.
5. 3- to10-pound blocks of ice
6. Insulating materials (Styrofoam, newspaper, etc.) for one aquarium
7. 3 thermometers
8. 1 lamp with a 50-watt bulb

Procedures:

1. Divide the class into 3 groups and assign 1 aquarium to each. Instruct each group to build a coastal community on one side of their aquarium. Make sure they leave room for the block of ice.
   • One end of the aquarium represents the ocean or sea level.
   • The land rises from sea level to a height of three-fourths of the opposite end.
   • Use the sand, dirt and rock and growing things to build your landscape.
2. Place the thermometers inside the aquariums so that they can be read without opening the top or disrupting the closed system.
3. Have the first group use the insulating materials to cover the outside of the aquarium, ensuring that there are view ports for observing the community and the thermometer. These view ports limit both the light and heat sources for this aquarium.
4. Have the second group arrange for the light to shine through the top of the aquarium to warm it up. Ensure that the electric plug is kept out of the aquarium. Do not insulate this aquarium. The last group should neither insulate nor heat their system.
5. Add one block of ice to the empty side of each aquarium and seal the aquariums tightly. Make sure that the aquariums are in the same area of the room and away from heating and cooling vents and windows.
6. Instruct each group to keep a log to record the temperature of the air inside the aquarium each day, the size of the ice block, the depth of water in aquarium and any changes in the coastal community.
7. Make daily entries until all of the ice has melted in each aquarium and the temperature is stabilized.
8. At the point of stabilization, use the following questions to discuss students' observations and to analyze the results of the experiment:
   1. What did the block of ice represent in your model?
      ANSWER: A glacier
   2. Why was one aquarium heated, one insulated and one left alone? Which aquarium do you think most accurately models Earth's current climate? Can you be sure? Why or why not?
      ANSWER: The heated aquarium represents a rapidly warming environment. The insulated aquarium represents a cold climate and the third most represents a climate neither rapidly warming nor overly cool. Other answers will vary depending upon students' understanding and acceptance of theories of global warming and its affect on glaciers.
   3. Describe some of the changes in the landscape as the block of ice melted. In which aquarium were the changes most pronounced? Which changes occurred most quickly?
      ANSWER: Answers will vary.
   4. Did the melting ice affect the highland parts of your ecosystem? How could you tell? On a continental scale, would the interior be affected by changes along the coast? Explain.
      ANSWER: Answers will vary.
   5. How could you redesign the human made parts of your community to lessen the effects of melting glaciers? Should community planners and developers of beachfront properties be aware of the possibility of increased sea levels? Do you think they are aware of these potential problems? If "yes," how should they address them? If "no," what could be done to get their attention?
      ANSWER: Answers will vary.
   6. How do these closed systems differ from the biosphere we call Earth? If the aquariums could have been designed to be more like Earth, how might the results have changed? Explain, taking into account the rise in "sea level," the water cycle, etc.
      ANSWER: They are too small to accurately reflect climate changes based on global warming or glaciation. Answers will vary.
   7. If students are interested, have them redesign this experiment, using research to create a tiny closed ecosystem similar to the glacial environment of Exit Glacier in Kenai Fjords National Park. Repeat the observations and analyze the results as before.

Part 3: Modeling the Effects of Glaciers on Sea Level

Before beginning the lesson, gather together the following materials and equipment:

• Water table
• Sand and gravel
• Ice block

Procedures:

1. Have students "build" glaciers by layering water, sand and gravel in a container. After the "glacier sandwich" has frozen, have them add another layer and freeze without allowing the initial layer to thaw. Repeat until the glaciers are the desired sizes.
2. On the day of the activity, add about 2 cm of water to the water table. Explain that this is the initial sea level. Have them determine the volume of the water and record the measurement in an observation log.
3. Remove the glacier from its form and place it in the water table. Have students measure the volume of the glacier and record this value.
4. Using these volume measurements, have students predict the final water volume and sea level when the glacier melts completely.
5. At intervals as the glacier melts, ask students to observe the nature of the glacier, noting areas of melting and the movement of the sand and gravel. Have them measure the depth of the "sea" also and record and graph these measurements.
6. When the glacier has melted completely, students will make a final measurement and record.
7. Use the following questions to discuss students' observations and analysis.
   1. Does the layered construction of the glacier model the real thing? Explain.
   2. What parts of the glacier are likely to melt first? Last? Explain.
   3. Will the final volume of the sea be equal to the initial sea volume and the glacier volume combined? Why or why not?
   4. If the glacier had been a block of ice as in Activity 2, floating in the sea, would the change in sea level have been different? Explain.
   5. What does this activity imply about the effects of global warming on the world's glaciers, ice fields and ice caps and the subsequent change in sea levels?

Invite students to write as science reporters for their local newspaper about melting glaciers and the effects global warming might have on their community, in particular, and on the United States in general. Edit the articles for clarity, scientific correctness and interest.

Part 4: How Might the Interaction Between Global Warming and Glaciers Affect Life on Earth?

Before beginning the lesson:

1. Print and distribute the EPA summary of the probability of rise in sea level (Probability of Sea Level Rise ) over the next several years.
2. Make copies of the Student Handout: Rising Sea Levels.

Procedures:

1. Have students read the summary and answer the questions on the Student Handout: Rising Sea Levels.
2. If students have not had time to complete the research in Part 1 above, Exploring Geophysical and Climate Changes During Periods of Glaciation and its Extension, have them do so now.
3. Allow time for class discussion of individual responses.
4. Have students form action committees to make plans to minimize disruption of the population as sea levels change over the coming years.

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