1. Types of Maps Mercator Projections Conic Projections
Gnomonic Projections
Topographic Maps

2. Mercator Projections Mercator Projection
Is a map that has parallel lines of longitude and latitude
Flaws
Land Near Poles is exaggerated
Shapes are correct, but land area is distorted

3. Conic Projections Conic Projection
Is made by projecting points and lines from globe onto a cone.
Very Little Distortion, High Degree of accuracy
Best for Mapping Small Areas
Used to make road and weather maps

4. Gnomonic Projections Gnomonic Projections
is made by projecting points and lines from a globe onto a piece of paper that touches the globe at a single point
Distort Directions and Distance
Used For Plotting great Circle Routes (Airplanes)

5. Topographic Maps Topographic Maps
Detailed maps that show the hills and valleys of an area
Use Lines, Symbols, and Colors to represent change in elevation

6. Map Features
Map Legends
Map Scales

7. Map Legends Include symbols for both man made and natural features
Specific Colors for Habitats
Green for Woods
Blue for Water
See Appendix D on p. 914

9. Map Scales Ratio of distance on a map to actual distances on the map
3 Types
Verbal: “one inch equals one mile”
Graphic: consists of a line that represents a certain distance on Earth
Fractional: one unit on map represents one unit on Earth
Large Ratio: map covering large area (minor detail)
Small Ratio: map covering little are (major detail)

11. Isolines
An isoline is a line connecting points of equal value.

12. Examples of isolines: (The weather channel loves isolines!) Isotherms:
points of equal temperature
Isobar:
points of equal barometric (air) pressure
Contour:
points of equal altitude
Concentration of chemicals
Anything else you can get a value for.
(The weather channel loves isolines!)

16. Rules for Drawing Isolines:
1. Isolines connect points of equal value. 5 5
10
10
10
10
15
15

17. 2. Isolines are gentle, curving lines- no sharp corners.5 5
10
10
10
10
15
15

18. 3. Isolines are always closed curves even though the map might only show part of it.

19. 4. Isolines NEVER cross- this would mean that one point has two different values. Ex: one spot has two temperatures?
60 °
50 °
40 °
30 ° X
20° Z Y

20. 5. Isolines usually are parallel. (They have a parallel trend.)

21. Visualizations of contour lines

23. Gradient
Gradient shows how quickly the value changes from one point to another.

24. A gentle (low) gradient changes slowly and the lines are far apart.
A steep (high) gradient changes quickly and the isolines are close together.
A gentle (low) gradient changes slowly and the lines are far apart.
Steep area
Gentle area

25. Making Contours worksheets
Worksheets can be printed from:

26. Highlight data points.

27. Fill in gaps in data.

28. Connect the dots.

29. Go on to the next value.

30. Making a Contour Map II

32. Drawing Contour Maps III