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Learner Outcomes:

By completing these activities, the learner will:

• Explain the processes of weathering and erosion in the wearing down of mountain environments.
• Identify three types of weathering: frost wedging, thermal expansion and organic.
• Explain the building up and recycling of mountains through natural processes.
• Determine area of mountain ranges using topographic maps.
• Compare and contrast different mountain ranges to determine similarities and differences.
• Compare climate data, topographic maps and visual images of eastern to western slopes of mountain ranges to generalize about differences in weathering and erosion.

Students need to understand how mountains are worn down by natural processes. The “Life Cycle of a Mountain” takes millions of years to complete. As soon as mountains are formed through the processes of plate movement, they begin to be worn down . To develop the concepts of weathering and erosion, experiment with activities that demonstrate different types of weathering and erosion.

• picture #1
• picture #2

3. To demonstrate Organic Weathering, observe seed roots as they grow in dirt. Take a walk around the school grounds and observe places where tree roots have created cracks or areas of upheaval in sidewalks, streets or the parking lot.

• picture #1
• picture #2

1. Physical erosion is caused by wind and water. To demonstrate, the teacher should dig up a piece of sod from the school yard and place it in an aluminum cake pan. To control variables, dirt should be dug from the same location (free of vegetation), and an identical cake pan should be filled with the same volume of dirt as the cake pan with sod. To conduct this experiment, both pans should be inclined at an identical angle on a table, with a pan below each one to capture runoff. An equal amount of water (measured carefully) should be poured on each pan. Sediments caught in each pan need to be dried out and weighed. This experiment could be repeated using an electric fan (on low) to simulate wind. What conclusions can be drawn from the amounts of sediment captures from each pan? The teacher might also want to repeat the experiment using pieces of sod with different types of soil and vegetation, since ground cover controls erosion.

Compare and contrast Appalachian and Rocky Mountain environments. These mountains are at different stages in their life cycle. Using the above pictures or other Internet images found at places like Great Smoky Mountain and Yellowstone national parks, create a Venn diagram which compares and contrasts these two mountain ranges. Begin by having students list observable differences and similarities for both types of mountain ranges. Discuss with the students the fact that the Rockies are newer mountains, and the Appalachians are older mountains that have experienced weathering and erosion to a larger degree, thus creating a more rounded mountainscape.

Concept Introduction:

At this point students should have an understanding of weathering and erosion and how these natural processes affect mountain environments.

Activity 1:

This activity is designed to compare Digital Elevation, topographic and land cover images available on the Internet:
 

Topographic Map links: National Geophysical Data Center Johns Hopkins University Applied Physics Laboratory (the elevation key can be found here.) USGS Flagstaff Center (Western U.S. only) Land Use Map links: Montana Wyoming Wisconsin Florida Region 3: DE MD, PA, VA, WV (Note: Other regions can be found here in the near future) Central United States Central Plains of United States USGS Geographic Analysis Project (GAP) (state homepages list;  most states not completed)

Viewing the images of both the Rocky Mountains and the Appalachian Mountains, compare and contrast differences in terrain and land use for both regions. Information can be added to the Venn diagram created earlier. Discuss information provided, including latitude and altitude. What generalizations can be made?

Import the topographic images into NIH image(Mac or PC)as a TIFF file. These can be converted using GIF converter (MAC) or Paint Shop Pro (PC) to save images as TIFF files. Using the appropriate scale from the map source, calibrate the NIH image file to scale. Highlight a specific pixel value at a specific altitude. The area of the region can now be calculated. Calculate the area of several different regions.

Using the above sites, obtain other images from your local area, or other areas of interest. Lead a discussion on what can be observed and learned from these images.

Activity 2:

This activity will compare climate and mountain environments on western and eastern slopes of mountain ranges. For the purposes of this lesson, data sets will be included for two cities on opposite slopes of mountain ranges.

Check out these links for two cities in the state of Washington, Seattle and Spokane, and check out these live pictures of Seattle. Information shown is the climate data for both cities, including rainfall information (current weather conditions for Seattle (CNN or Weather Channel) and Spokane (CNN or Weather Channel)). Both cities are at similar latitudes; however data shown indicates a significant difference in climate and rainfall. Note the topographical map of Washington state. What lies between these two areas? How does the topography affect the rainfall? What have we learned about how rainfall affects weather? What differences are noted?

Using land use maps, Internet resources of Seattle and Spokane, and topographic maps of Washington state, compare the mountain environments close to both cities. How has rainfall differences affected weathering and erosion of these easterly/westerly mountain slopes? What generalizations can be made?

What can be concluded about weathering and erosion of mountain regions from this activity? How have the western and eastern slopes weathered differently? Is there a link between erosion and climate/rainfall data?