Glaciers
Instructor: Deborah M. Szmaida
Introduction
Glaciers contain nearly 75% of our fresh water. Glaciers, either flowing rivers of ice or large
continental ice sheets, have advanced and retreated over thousands and thousands of years
reshaping the landscape as they go. Between 15,000 and 18,000 years ago a continental ice
sheet was at it furthest extent and reached as far south as Northern
Picture: http://calspace.ucsd.edu/virtualmuseum/images/raw/IA_Fig7_0_2.jpg
New Jersey. Many of the natural lakes in Sussex, Warren, and Morris counties were created by
retreating glaciers. Some examples are Swartswood Lake and Culvers Pond in Sussex County,
White Pond in Warren County, and Green Pond, Budd Lake, and Lake Hopatcong in Morris County
(Wolfe, The Geology and Landscapes of New Jersey).
Glaciers were a large factor in shaping the present day landscape in New Jersey, but what are
glaciers, how do they form, and how do they shape the landscape?
The Task
After completing the classroom opening activities, gather information about glaciers as outlined
on the worksheet provided, record what you learn on the worksheet provided. Use the
hypertext links to find the appropriate information, if necessary use the additional resource
links listed below. Use the information you gather to respond to the opening activities you
participated in prior to doing this research.
Virtual Glacier Exploration
1. What is a glacier?
2. How do glaciers form? Complete the diagram showing the steps a snowflake tokes to become
glacial ice.
3. Compare ice sheets and valley glaciers. How is a valley glacier system like a
stream/river system? Give examples of where each kind of glacier can be found.
4. Scroll down and read the paragraph that is to the right of the diagram on your worksheet
showing the primary parts of a glacier.
5. Glaciers increase in size when more snow accumulates than melts. When a glacier shrinks, or
ablation, more of the ice melts than the glacier gains from snow. Glaciers grow and shrink and
they also move. Summarize how a glacier moves.
Glaciers alter the landscape in many ways but they are all either by erosion or by deposition.
6. Briefly describe the glacial erosion actions of plucking, abrasion, and conveyor belt.
7. Briefly describe glacial deposition action
8. View the pictures and briefly describe each of the following glacial erosion features:
U-shaped valleys, hanging valleys, and striations.
9. The Great Lakes located between the United Stated and Canada and the Finger Lakes in New
York are examples of large scale landscape features that were created by erosion caused by
glaciers.
View FlashMovie of the formation of the Great Lakes.
10. View the pictures and briefly describe the following glacial deposition features: till,
erratics, moraines, kettle ponds, and drumlin.
11. What is the difference between a lateral moraine and a terminal moraine?
12. Cape Cod Massachusetts and Long Island New York are examples of large scale landscape
features created by depositions by glaciers.
13. What is an iceberg? Where do most icebergs come from?
14. Visit the photo gallery. Print your favorite glacial picture (only one please) and paste it in
the space provided on your worksheet. Describe the picture and identify where the picture was
taken.
Extending Your Knowledge
1. Would cold winters or cool summers cause glaciers to grow? Explain.
2. Glaciers are retreating rapidly and as a result icebergs are more abundant, in greater
quantities, than ever. Is this a cause for concern for the transportation of goods from
continent to continent? Explain.
3. Glaciers are retreating, it is claimed that global warming is the reason for this, but could
soot, dust, and volcanic ash also contribute to the melting of glaciers? Explain.
Conclusion
By the end of this activity you should be able to
• Describe what a glacier is and how it is formed.
• Identify the two basic kinds of a glacier.
• Know that glaciers shape the landscape by erosion and deposition.
• Identify landforms that were created by glaciers.
• Be able to use the knowledge to complete the classroom activities started in the
introduction to glaciers.
Resources
Websites
http://www.glacier.rice.edu/land/5_whatisaglacier.html
http://www.glacier.rice.edu/land/5_howdoesaglacierform.html
http://www-nsidc.colorado.edu/glaciers/story/grow.html
http://www.glacier.rice.edu/land/5_iceofallshapes.html#anchor6097245http://www.geophys.wa
shington.edu/People/Students/ginny/antarctica/lesson4.htm
http://www.zephryus.demon.co.uk/geography/resources/glaciers/ushape.html
http://www.glacier.rice.edu/land/5_erosioalsubglacial.html
http://www.zephryus.demon.co.uk/geography/resources/glaciers/stria.html
http://www.davison.k12.mi.us/bentley/glaciers.htm
http://www.geophys.washington.edu/People/Students/ginny/antarctica/lesson4.htm
http://www.on.ec.gc.ca/greatlakeskids/GreatLakesMovie5.html
http://pubs.usgs.gov/gip/capecod/fig3.html
http://www.uwsp.edu/geo/faculty/lemke/alpine_glacial_glossary/landforms/u_valley.html
http://earthsci.org/teacher/basicgeol/global_warm/global_warm.html#Climate%20variations
http://www.thewe.cc/contents/more/archive/december2003/black_soot_causes_global_warmi
ng.htm
Books
Wolfe, Peter, The Geology and Landscapes of New Jersey
Raymo, Chet and Maureen, Written in Stone: A Geological History of the Northeastern United
States.
It’s About Time, pages 233 – 256.
Rubric for Evaluation
See student worksheet