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The Wisconsin Ice Age

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					The Wisconsin Ice Age
        By Tim Greene
                 Overview

•   How the last Ice Age began
•   The Wisconsin Ice Age
•   Glacial Movement and Effects on Land
•   Glacial Features
•   Review Questions
      How did the Ice Age Begin?

• The ice age began when the global temperature
  dropped which caused ice to freeze up into large
  masses.
• So much of the ocean’s water became frozen that
  the sea level dropped approximately 100 feet.
• The sheet of ice that was concentrated over North
  America was known as the Laurentide Ice Sheet
• The glaciers thrived on cool summers and wet, mild
  winters .
 Sea Surface Temperature
This map represents the sea surface temperature during the month
of February in the last glacial maximum.
Annual Surface Air Temperature
 This model shows the annual surface air temperature during the
 last glacial maximum.
            The Wisconsin Ice Age
• The Wisconsin Ice Age lasted roughly from 100,000 years – 10,000
  years ago in North America.
• Massive ice sheet, up to 8,000 feet thick, covered much of the
  continent from as far south as 37°N latitude.
• The glacial maximum occurred around 20,000 years ago and was
  the strongest episode of the entire period.
• During this time, the sea levels were lowered so much that they
  exposed a land bridge known as Beringia that connected Asia and
  North America.
• Glacial movement during this time had an enormous impact on
  altering the landscape in the Upper Mississippi River and the Ohio
  River Valley.
• The Great Lakes formed when the Laurentide Ice Sheet melted.
• Massive weight of the ice sheet compressed the continental crust
  down and is still rebounding today.
Extent of Glaciation
             How do Glaciers move?
• Glaciers are able to move
due to waters sensitivity to
pressure which causes its
melting point to decrease
as pressure increases.
• The bottom of the glacier
is under tremendous
pressure which
accompanied by latent
heat from the surface of
the earth causes the
bottom of the glacier to
become liquid.
• Runoff from under the
glaciers allows the glacier
to slowly move forward
between a few inches and
a few feet per day.
                      Effect on Land Use
•Nutrient rich glacial deposits play
an important role on how we
produce food and other useful
trade products
•Sediment deposit has allowed
agriculture to soar in regions with
uniform till texture.
• Areas with lots of sediment
benefit economically by quarrying
stones to build roads and other
construction mediums.
• Carved valleys and waterways
into the continent which help
supply us with fresh water for
drinking as well as other means of
commerce.
             Glacial Features

• Drumlins
• Moraines
• Kettle
• Erratic
                 Drumlins
Oval tear-drop shaped hill formed underneath the ice at the
advancing front of the glacier.
                         Moraines
Scattered hills of unsorted, unstratified debris found at the front or side of
the glacier.
                              Kettle
Depression formed by the melting of a block of glacial ice that was at
least partially buried
                          Erratic
Boulders and large rocks that were carried by glaciers and deposited in
different locations
   What is the name for the glacial
 feature that this area is made up of
and what is this area known as today?
          Moraines and Long Island
                   True or False
1. Glaciers thrive on dry, cold winters.
  False, glaciers prefer wet, mild winters in
  order to renew their ice pack

2. Ice Ages are caused by many different
    factors.
  True
                                                Works Cited
Anissimov, Michael. What is the last Glacial Maximum? (2003-2010). WiseGeek. Retrieved on (April 25th, 2010) from
      http://www.wisegeek.com/what-is-the-last-glacial-maximum.htm

Briedis, Cindy A. Illinois State Geological Survey. (2009, September 17th). Why We Study Glacial and Quaternary Geology. Retrieved on
     (March 27th, 2010) from http://www.isgs.uiuc.edu/research/glacial-geology/why-glacquat.shtml

Jule, Hort, James and Sleeth, Brad. A Virtual Field Trip Through Northeastern Illinois. (2000, November 21 st). Glaciers.
      Retrieved on (March 27th, 2010) from
      http://jove.geol.niu.edu/faculty/fischer/429_info/429trips/NIF/Glaciers.htm#_Illinois_Glacial_History

National Snow and Ice Data Center. (n.d.). How do glaciers affect the land? Retrieved on (March 25 th, 2010) from
     http://nsidc.org/glaciers/questions/land.html

University of Wisconsin Sea Grant Institute. (2008). The Great Lakes. Retrieved on (March 27 th, 2010) from
     http://seagrant.wisc.edu/glaciers/

Wisconsin Department of Natural Resources. (2009, May 29th). The Ice Age in Wisconsin. Retrieved on (February 20th, 2010) from
     http://www.dnr.state.wi.us/ORG/LAND/parks/specific/iceagetrail/iceage.html


Image Sources:
http://oz.plymouth.edu/~sci_ed/Turski/Courses/Earth_Science/Images/4.drumlin.jpg
http://www.nps.gov/ser/pgallerycontent/p/l/20060922165616.jpg
http://www.awi.de/fileadmin/user_upload/News/Press_Releases/2006/1._Quarter/Glacier2_p.jpg
http://upload.wikimedia.org/wikipedia/commons/c/cb/Kettle-glacial-lake-form-isunngua-greenland.jpg
http://www.stanford.edu/~siegelr/chile/glacialerratic.jpg
http://oz.plymouth.edu/~sci_ed/Turski/Courses/Earth_Science/Images/9.glacier.JPG
http://seismo.gphys.unc.edu/~raj/acc/wp-content/uploads/2008/06/annual_surface_air_temperature.png
http://upload.wikimedia.org/wikipedia/commons/c/c0/Long_Island_Landsat_Mosaic.jpg
http://standeyo.com/Reports/Ice_age/ice.age.mapl.lg.jpg
http://www.californiagreensolutions.com/images/Jepson-WCS3279b.jpg

				
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