1. Representing Earth’s Surface
Chapter 1
Section 3

2. Determining Location
Latitude and longitude are lines on the globe that are used to determine location.
Latitude is distance north or south of the equator, measured in degrees.
The middle latitude, at 0 degrees, is the equator
Longitude is distance east or west of the prime meridian, measured in degrees.
The middle longitude, at 0 degrees, is the prime meridian

3. Royal Observatory in Greenwich, London

5. Globes Advantages: Accurate shapes and sized of continents
Disadvantages:
Too small to show details

6. Projection Maps: Mercator Projection
Advantages
Rectangular
Longitude lines are parallel
Directions shown accurately
Disadvantages
Sizes and distances distorted

7. Projection Maps: Robinson Projection
Advantages
Most distances, sizes, and shapes are accurate
Disadvantages
Distortion around edges of maps
Discuss: How do shapes in the continents differ between the Mercator and the Robinson maps?

8. Projection Maps: Conic Projection
Advantages:
Great accuracy over small areas
Used for road and weather maps
Disadvantages:
Lots of distortion on most of the map

9. Projection Maps: Gnomonic Projection
Advantages:
Reliably shows the shortest distance between two points
Disadvantages
Exact distances and directions distorted

10. Topographic Maps
Topographic maps represent Earth’s surface in three dimensions; they show elevation, distance directions, and slope angles.
Contour lines are lines on a topographic map that indicate an elevation. (hachure marks)
Contour interval is the distance in elevation between adjacent contour lines.

11. Topographic Maps Discuss: Where is the land flattest?
Where is the land steepest?
How do the contour lines show a stream?

12. Geologic Maps
A map that shows the type and age of exposed rock

13. GPS

14. GPS
Satellites and computers allow scientists to more precisely analyze Earth’s physical properties.
Can detect latitude, longitude, altitude/elevation, speed, and direction
Three satellite signals are detected by a receiver. The distance from the satellites to the receiver is calculated, and the location is determined using the triangulation method. A fourth signal is then used to mathematically determine exact position.

15. Review
Describe the two sets of lines that are used on globes and some maps
What happens to images from a globe when they are transferred to a flat surface?
What is the purpose of contour lines on a topographic map?