MAPS AS TOOLS
Teacher Outline
* Teacher Outline included in Teacher Guide Download

I. What is a landform?

The shape of the Earth’s surface that has been accomplished by erosion or tectonic activity.

  1. Influenced by climate and rock type
      

  2. Erosion includes water, ice, glaciers and heat
      

  3. Tectonic includes earthquakes and volcanoes

II. Erosion and Weathering

Erosion is the process that loosens and moves sediment to another place on the Earth’s surface; weathering is the chemical and mechanical breakdown of rock with little or no transportation

  1. Rocks erode at different rates so there are areas that are more resistant than others; this can produce different types of landforms with ridges, cliffs, or gentle slopes
      

  2. Running water erodes areas in predictable stages depending on the amount of rain and the type of rock it is eroding; tectonic activity influences this erosion (i.e. Grand Canyon needed uplifting of rocks for the water to keep eroding downward)
      

  3. Almost every landform on the continent is related to a drainage system as water finds its way to large bodies of water

  1. water is an overlay of other features caused by tectonics

  2. rivers cause "V" shaped valleys because of the movement of the sediments downstream

  1. Ice is important feature in areas where it is cold throughout the year, but this is restrictive to the northern and southern pole areas

  1. Ice is more powerful than water for its erosive forces

  2. Glaciers can create U shaped valleys as they abrade the rocks around them; their flow pattern is like a river
    3. Continental or sheet glaciers erode large area, contours are more difficult to interpret with many different parameters

  1. Wind is important is arid areas

  1. causes desert polish, where the rocks are smooth on the side that the wind hits

  2. desert pavement where there is polished large pebbles and cobblestones left; small sediment is removed by wind

  3. sand dunes are created as wind drops the sediment in a predictable pattern

III. Tectonic Activity

  1. Movement on the Earth’s crust can cause earthquakes. The movement is usually along a fault which can move in many ways.

  1. Mountains - one side of the fault can move upwards

  2. Offset streams - as a fault slides away from each other the river will compensate and become offset

  3. Basin and Range - where basins are pulled apart and cause some areas to go up and some to go down

  1. Volcanoes

  1. Lava flows can create a landscape that is made of volcanic rocks. It will cover the pre-existing land to create a new landscape.

  2. Ash flows from erupting volcano can cover vast areas. They can even cover an entire city (i.e. Pompeii, Italy)

  3. Mud flows can form when snow or glaciers are melted and mix with ash. The flow is very large and can cover huge amount of lands that bury everything in its path.

IV. How do maps act as a tool

  1. Designing an urban area requires an understanding of relief

  1. Example: creating water or sewage flow to and from a house, need to incorporate slopes to help gravity flow the liquid.

  2. Designing a road, do not want to make it too steep or trucks cannot drive

  3. Do not want to make homes along steep cliffs

  1. Workable area

  1. A map can be used to develop different models at a scale that humans can work with

  2. A map can be modified, where the real land is more difficult to modify after changes have been made
 
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