AN
INTRODUCTION
TO
GLACIERS

VIOLET POLING
ALASKAN STUDY CRUISE
JULY 17-31, 2001

PURPOSE

The purpose of these lessons is to introduce the children to how glaciers change the physical features of the land they pass over.

OBJECTIVES

As a result of this learning, students will:

1. Explain how constructing a model and writing the explanation in paragraph form forms a glacier.
2. Recognize that there are different types of glaciers by viewing a power point presentation.
3. Identify the location of past and present glaciated areas in North America by constructing a map.
4. Compare the glaciers of Alaska today to the ice sheets that covered Illinois thousands of years ago by constructing a map and through group discussion.
5. Describe how the ice sheets affected the land formation of Illinois by studying a landform map of Illinois and comparing it to the glaciation map of Illinois.

GRADE LEVEL

Third through sixth

DURATION

Two to three lessons

CONNECTION TO CURRICULUM

Social studies; language arts; math

GEOGRAPHIC STANDARDS

Element I: The World in Spatial Terms

Standard 1: How to use maps and other geographic representations, tools and technologies to acquire, process and report information from a spatial perspective.

Element III: Physical Systems

Standard 7: Physical processes that shape the patterns of Earth’s surface.

Element VI: The Uses of Geography

Standard 17: How to apply geography to interpret the past.

Standard 18: How to apply geography to interpret the present and plan for the future.

ILLINOIS STATE SOCIAL SCIENCE GOAL

State goal 17: Understand world geography and the effects of geography on society, with and emphasis on the United States.

State Academic Standard:

A. Locate, describe and explain places, regions and features on the Earth.
B. Analyze and explain characteristics and interactions of the Earth’s physical systems.
D. Understand historical significance of geography.

BASIC GEOGRAPHIC SKILLS

Acquiring geographic information
Analyzing geographic information

MATERIALS NEEDED

Maps (hard copy and overheads)
Illinois Glaciation
Illinois Landforms
Glaciers of the World
Notebook to record summary of daily lesson
Pictures showing glacier formations
Power point presentation
Vocabulary list

SUGGESTED TEACHING PROCEDURE

LESSON ONE

Opening the lesson:

1. Brainstorm ideas

a. What is a glacier?
b. How is a glacier formed?
c. Where do you find glaciers today?
d. How are glaciers different?
e. How many glaciers covered Illinois and receded?

2.Share pictures and diagrams about glaciers from books.

Developing the lesson:

1. Provide the children glacier information through use of pictures and diagrams.
2. Develop a vocabulary list with use of pictures and other visual clues.
3. Use "Glaciers of the World" overhead.

Closing the lesson:

1. Children will color the regions of glaciers today and glaciers of long ago on a map designed for this purpose. (Remind children that a map must have a title, a key, and must be neatly completed.)
2. Children will write in their journal a summary of what they learned about the location of glaciers.

 

LESSON TWO

Opening the lesson

1. Review how a glacier is formed.
2. Using the completed map of the previous lesson, review the location of the glaciers today and why the glaciers are located mostly in Alaska and Greenland. (Latitude)

Developing the lesson:

1. Ask the question "Are all glaciers alike?" Use pictures to show ice sheets of thousands of years ago and glaciers of Alaska today.
2. Explain that during the Ice Age there were sheets of ice that covered North America.
3. Explain that during the Ice Age 30% of the world was covered by ice but today only about 10% of the world is covered by glaciers.
4. Children study the map they completed and conclude that part of Illinois was covered by glaciers. Discuss with them how these ice sheets changed the land formation of Illinois. (flat lands; Lake Michigan formation; unglaciated areas more hilly, etc.)

Closing the lesson:

1. Use "Glaciation of Illinois" overhead to show where the different ice sheets covered Illinois.
2. Children will color in the different ice sheets on a map.
3. Children will write a summary or reflection in their notebook about the ice sheets that covered Illinois and how these ice sheets changed the land formation of Illinois.

LESSON THREE

Opening the lesson:

1. Review how the ice sheets changed the land forms of Illinois by studying their completed map.
2. Review how the ice sheets are different from the Alpine glaciers of Alaska.

Developing the lesson:

1. Ask "What changes occur to the plants and animals when a glacier covers the land?"
2. Use "Landforms of Illinois" overhead to show the prairie land of central Illinois, plains along Lake Michigan, and the rolling hills of the unglaciated areas.
3. Use "Landforms of Alaska" map to show mountains, glaciers, waterways, and limited amount to growing soil.
4. Ask "How have these changes affected the growth of Alaska? of Illinois?

Closing the lesson:

1. In their journal, answer the questions:

"How have these changes affected the growth of (Alaska or Illinois)?
"In which state would you rather live and why?"

2. Evaluation -- complete the "L" of the K-W-L chart

 

Alaska’s Glaciers

In the Pleistocene Epoch from 2-1/2 million to about 10,000 years ago, nearly one-half of the North American continent was covered by glacial ice. The glaciers covered 30 percent of the earth’s land surface, and today cover ten percent, most of it in Greenland and Antarctica. Global warming and shrinking of glaciers left Alaska with most of this continent’s glaciers.

There are two main kinds of glaciers, continental glaciers and valley glaciers. They differ in size, shape, and location. Continental glaciers are broad, extremely thick ice sheets, (as thick as 15,000 feet) that cover vast areas of land near the polar regions. The continental glaciers covering Greenland and Antarctica, for example, bury mountain ranges and plateaus and conceal the entire landscape except for the highest peaks. Valley glaciers are long, narrow bodies of ice high mountain valleys. They move down sloping valleys to lower, warmer elevations where melting occurs. Some of these, including many Alaskan glaciers, reach sea level and are termed tidewater glaciers.

Eight states in the lower 48 contain more than 1,000 glaciers collectively, but these cover only about 205 square miles. Combined, Alaska has over 100,000 glaciers covering about 30,000 square miles, or about three percent of the state’s land area. Some ice fields greater than 200 square miles are not even named. Malaspina Glacier alone is greater in are than the state of Rhode Island.

Glaciers usually advance with "glacial speed", often a few inches or a few feet per day. Occasionally a glacier will "surge", or flow upward at a much more rapid rate, sometimes 100-200 feet per day; some have been known to surge at more than a thousand feet per day. In 1986, Hubbard Glacier in Yakutat Bay advanced across the mouth of Russell Fiord, creating a lake whose level rose more than six inches a day from rain and glacial melting. "Russell Lake," rose 80 feet above sea level behind the ice dam of Hubbard Glacier before the dam began to break up, resulting in the emptying of Russell Lake down to sea level within a of about ten hours. The lake level dropped about 5-1/2 feet per hour, with an outflow 35 times that of Niagara Falls.

Retreat of Alaska’s glaciers in the last 200 years has been dramatic. Two hundred years ago, there was no Glacier Bay. The glacier occupying it was 15 miles wide at its terminus, and the ice varied from 2,000 feet thick at the terminus to 4,000 feet thick at it’s head. The glacier has retreated 65 miles in less than 200 years. Glacier Bay now contains 16 glaciers, remnants and tributaries of the glacier once filling the bay. These include the largest collection of tidewater glaciers in the world. There are 13 of them.

One of Alaska’s largest and best known glaciers is Columbia Glacier in Prince William Sound, only eight miles from the shipping lanes plied by oil tankers leaving the Alaska pipeline terminal at Valdez. The threat of icebergs from the Columbia Glacier in 1989 caused the Exxon Valdez to alter course, with disastrous results. Columbia Glacier is 41 miles long, covers 440 square miles, and flows to sea level from 10,000-12,000-foot peaks in the Chugach Range. It is fed by four main tributary glaciers. Its width at the terminus varies from two and a half to four miles, and the ice at that point probably averages 800-900 feet high. The ice face visible from cruise ships is 200-300 feet high. This glacier is being carefully monitored, as it began receding over a decade ago. It has the potential to send more icebergs into shipping channels as it recedes. The glacier is expected to recede over the next 20-50 years, reducing its length by half, creating a fiord over 20 miles long and as deep as 2,300 feet. Fortunately, a shallow sill, or shoal, of underwater glacial deposit keeps icebergs more than a hundred feet thick from escaping into Prince William Sound.

WP 7/29/91

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