Web quest: Glaciers

Name ________________________________________________________

Procedure 1.  Use the first  link below  to learn about ice cores and Antarctica by answering the questions that follow.

http://www.pbs.org/wgbh/nova/warnings/stories ice cores and Antarctica

1. Initial Page: Scroll to the second paragraph.  Ice cores reveal the past.  What does each layer of ice represent?______________________ Each layer records events such as _______________________________ and ________________________. 

2. Click on the icon for Ice Core Timeline.  Choose “Air Pollution”.  Use the graphs to identify the levels of the following pollutants in 1900 and then in 2000:

Methane___________________ Carbon Dioxide ______________ Nitrates ______________________

3. During that time period the world population rose from _____________ people to ______________ people. 

4. Choose “Global Warming”.  How many years do these cover? ________________  What relationship between CO2, methane and warming does this graph indicate? _______________________________________________________________________________ 

What was the warmest period of the past 160, 000 years? ______________________ 

5. Choose “Sea Storminess”.  What may have happened to the Vikings? _________________________________________________ 

6. Choose “Antarctic Almanac” from the menu on the left of the webpage.  What percent of the world’s total ice does Antarctica contain? _______________ How thick is the thickest ice? ______________  What does the weight of the ice do to the shape of the earth? ___________

7. Scroll down to “Land”.  What is the name of the mountain chain? __________________________  What is the annual mean temperature of Antarctica? _________________

8. Scroll to “Water”.  How much precipitation does Antarctica receive per year? _____________

What is the circumpolar current? _________________________________ What would happen to world sealevels if the West Antarctic Ice Sheet were to melt? ________________ If the East sheet melted also? ____________________

9. Scroll to “Glossary”. What is the Katabatic? _________________________________ _______________________________  

10. Go back to top of page and choose ‘Water World’ from menu.  Review the first 3 pictures that show the northeast US 20,000 years ago, if the West sheet melted and if the East sheet melted.  Briefly describe the change in sea level that Manhattan would experience.  How would our situation in Orange County be different in each?

20,000 years ago: _____________________________________________________

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West sheet melt: ______________________________________________________

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East sheet melt: _______________________________________________________

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Procedure 2. Go to the webpage below and answer the following questions about glacial loss.

http://nsidc.org/data/glacier_photo/repeat_photography.html matched photos of glacial change from the page: http://nsidc.org/glaciers

1. Enlarge the picture of the Muir Glacier.  Identify the dates photographs were taken.  _____________________Describe the ice loss and the features revealed by the retreat of the ice. _______________________________________________________________ __________________________________________________________________

2. Compare the changes in the McCall Glacier to those of the Muir Glacier. _________ ____________________________________________________________________

Procedure 3. View the pictures shown on each of the web pages and answer the simple questions about them.

1. http://epod.usra.edu/archive/epodviewer.php3?oid=50784 this EPOD picture shows movement of part of the Antarctic Ice Sheet.  The color codes are given in the top right part of the picture. What are the speeds of the middle __________________ and edges of the glacial ice sheet? _______________ 

2. http://epod.usra.edu/archive/epodviewer.php3?oid=92896 What happened to the Larsen B ice shelf? ____________________________________ .  Include the date of the occurrence._________________ 

3. http://epod.usra.edu/archive/epodviewer.php3?oid=108640 In your own words, describe what the photograph shows. ______________________________________________________________  ______________________________________________________________________________

4. http://epod.usra.edu/archive/epodviewer.php3?oid=120832 What has happened to the “Snows of Kilimanjaro” in the past few decades? _____________________________________  What is the prediction for the glacial snows? _________________________________________________________

Procedure 4.  How the global ice cover changes.

Go to http://www.nrmsc.usgs.gov/research/glacier_model.htm from the USGS site and watch the animation that shows both past glacial positions and predicts future positions.  Summarize the change.  Scroll down to the diagram of the Terrain and then to the diagram that indicates sun strength.  Go back to the animation.  Is there a connection among terrain height, sun strength and glacier position? ____________________________________________________________________________________

____________________________________________________________________________________

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Procedure 5: Check out some pictures.

For a good series of photographs, this page has menus of pictures from different parts of the world. http://www.canada-photos.com/glacier-ice-yukon-territory-464-pictures.htm  
 

ON YOUR OWN:  for extra credit on a separate piece of paper http://earthobservatory.nasa.gov/Observatory/Datasets/snow_ice.smmr.html build an animation that shows the change in snow and ice depth for the past 3 decades. Use 3-4 sentences to fully describe both the seasonal fluctuations evident and the changes occurring over the past few decades.

http://ak.water.usgs.gov/glaciology/gulkana/index.html Gulkana Glacier homepage.  Identify changes in ice thickness, mass balance, stream behavior.  Find it on a map.  How long has it been studied?

Photographs to view on your own. http://www.cosleyhouston.com/news10-02.htm alpine guide. 

View topographic maps that identify glacial depositional and erosional features. http://www.csus.edu/indiv/s/slaymaker/Archives/Geol10L/landforms.htm landforms on topo maps