1. Mapping Earth’s Surface

2. Isolines Common examples of isolines include:
This isoline indicates an elevation of 3000 feet.
Isolines
Common examples of isolines include:
ISOTHERMS = lines of equal temperature
ISOBARS = lines of equal air pressure
CONTOUR LINES = lines of equal elevation
Contour lines

3. Gradient: Changes in Fields
gradient = change in (amount of) field value
change in distance (horizontal distance)
RT = Pg. 1
What is the temperature gradient between two cities in North Carolina on the date shown?
Gradient = change in (amount of) field value
change in distance (horizontal distance)
City B = 30°F
City A = 42°F

4. Contour Maps
Contour maps are used as hiking aids, planning for areas of construction and resource development.
Brown = landforms/elevation Blue = Water features
Green = woodlands Red/Black = Human constructs (boundaries, roads, etc..)

5. Reading a Contour Map

6. The contour interval for this map is 10 ft.
Reading a Contour Map
A depression is represented by “hachures” on the contour lines. The first “depression contour line” will have the same contour interval as the last contour line.
Each succeeding “depression contour line” will be drawn at the same contour interval as the rest of the map.
The contour interval for this map is 10 ft.
This first “depression contour line” would have an elevation of 140 ft; the same as the previous contour line.
The second “depression contour line” would have an elevation of 120 ft.

7. Determining Horizontal Distance on a Contour Map
The horizontal distance on a contour map is usually represented as a map scale in the legend of the contour map.
To determine the horizontal distance between two locations on a contour map:
Place a piece of paper with a straight edge on the map and mark the two locations
Match up the marks on the map scale to estimate the horizontal distance between the two points.
What is the distance between the school and post office?
2.3 km

8. Topographic Profile
A topographic profile is a cross section of a landscape constructed from data collected from a contour map. To make a topographic profile, complete the following steps:
Place the edge of a strip of paper along the line to be profiled.
Make a mark on the paper at each point where a contour line crosses it. Record the elevation at each point.
Align the paper along the x-axis of a graph and plot the points of elevation onto the graph.
Connect the points with a smooth, curved line.

9. Where can Bluewater Lake be found with relation to Kennedy Lake?
Map Direction
Maps are usually constructed so that geographic North is at the top of the map.
An arrow or a “compass rose” is most usually placed on the map to show the direction of geographic North.
Knowing where North is on a map, allows the observer to determine the other 7 cardinal directions
Compass Rose
Where can Bluewater Lake be found with relation to Kennedy Lake?