Adventist Youth Honors Answer Book/Recreation/Orienteering

1. Explain what a topographic map is, what you expect to find on it, and three uses for it.

Topographic maps are also commonly called contour maps or "topo maps." Topographic maps conventionally show topography, or land contours, by means of contour lines. Contour lines are curves that connect contiguous points of the same altitude. In other words, every point on the marked line of 100 m elevation is 100 m above mean sea level.

Other than showing elevation via the contours, you can also expect a topographic map to show any important landmarks, such as rivers, lakes, and roads. They will often also show railroad tracks and major power lines (and their towers). Power lines are especially handy because the towers are visible from great distances and each represents a point on a map (whereas a road or river would represent a curved line). These attributes make them ideal for pinpointing position.

Topographic maps have many uses, letting a competent user determine any of the following:

• Where he is.
• How to get where he wants to go.
• What the terrain is like in a given area (steepness, for example).
• Where a river comes from and goes to.
• The route a hiking trail follows.
• The location of campsites.
• The distance between to points.
• Elevation of a mountaintop.
• Latitude and longitude of any point on the map.
• What areas may be susceptible to avalanches or flooding.

2. Identify at least 20 signs and symbols used on topographic maps.

Map Symbols

4. Know the meaning of the following terms:

a. Elevation

The height of a point relative to sea level.

b. Contour interval

The elevation change between adjacent contour lines on a topographic map. If you travel from one contour line to another, your change in elevation will equal the contour interval.

c. Magnetic North

Magnetic North is the direction a compass will point, which is towards the North Magnetic Pole. The North Magnetic Pole is not the same place as the Geographic North Pole. The North Magnetic Pole is the point on the Earth's surface where the Earth's magnetic field points directly downwards. This pole is constantly wandering; its estimated 2005 position was 82.7° N 114.4° W.

d. Declination

The angular difference between magnetic north and true north (defined in reference to the Geographic North Pole), at any particular location on the Earth's surface, is called the magnetic declination. In other words, it's how far off a compass is from True North, or the correction that must be applied to a compass reading.

e. Scale

f. Measuring

g. Back-azimuth

h. True North

True North is the direction from any point on the Earth's surface to the Geographic North Pole.

i. Azimuth

j. Distance