Map Compass

1. Map & Compass Developed from: The Essential Wilderness Navigator By David Seidman & Paul Cleveland

2. Types of Maps

3. USGS Topographical Maps Symbols Legend Contour Lines Slope Profiles Slope Gradient Latitude & Longitude Scale Declination

4. Perspectives

5. Shaded Relief

6. Reading the Terrain

7. Contour Lines

8. Rules for Interpreting Contours There is no beginning or end to a contour line. It is an irregularly shaped closed loop. The steeper the slope, the closer the spacing between lines. Your trail is going uphill if it regularly crosses contour lines of increasing elevation. Valleys usually show up as a series of V-shaped lines pointing toward higher ground. Ridges can be shaped like a series of V�s or U�s pointing toward lower ground. A pass or saddle in a ridge has higher contour lines on each side, giving it a characteristic hourglass shape.

9. Rules for Interpreting Contours To determine if a group of U or V shaped contours shows a ridge or a valley, check the elevation of the contour indexes to see which way the ground is sloping, or check to see if a stream runs down the middle or side of the V�s. Contour lines running up one side of a river or stream, crossing it, and running back down the other side form a U or a V that points upstream. A peak is depicted by the innermost ring of a near-concentric pattern of contour lines. It is marked with elevation and sometimes an X.

10. Scale A map is reality reduced to manageable size, with every detail uniformly proportioned to what it represents. The maps scale, or degree of reduction, is noted along its bottom border. Scale is most often expressed as a ratio called representation fraction. A scale of 1:24,000 means that 1 inch on the map represents 24,000 inches in the real world. The bigger the second number, the smaller the scale: the smaller the second number, the larger the scale.

11. Slope Gradient We utilize slope gradient as an important variable in determining a trails level of difficulty. The change in elevation, which is the vertical distance (contour lines) The length of the trail, which is the horizontal distance (maps scale)

12. Route Profile

13. Slope Perspective Four views of a mountain. A familiar landmark can look very different when viewed from an unfamiliar perspective.

14. Latitude & Longitude Lines of latitude run horizontally, East & West, and lie parallel to one another. Measure distance North & South of the equator. Lines of longitude run vertically North & South, but are not parallel. Measure distance East & West of Greenwich, England.

15. Which Way is North? Geographic or True North At one end of the axis around which the earth spins. Map makers place geographic North at the �top� of the world. Magnetic North At the Northern end of the planets magnetic core, West of Baffin Island. The compass is attracted to magnetic North.

16. Declination: The Difference between Geographic and Magnetic North

17. Direction

18. Compass Types

19. Baseplate Compass

20. When All Else Fails Iron or Steel A pin or Needle Piece of Barbed Wire No Drafts Small Container Magnetize if Possible Magnet Stone Silk

21. Map Software TopoUSA

22. Skills Challenge topoliteracy

23. Challenge Test your topoliteracy by matching the topo views on the left (1 � 5) to the appropriate profiles on the right (A � E). 1 = B 2 = E 3 = A 4 = C 5 = D1 = B 2 = E 3 = A 4 = C 5 = D