1. UNIT V: EARTH’S COORDINATE SYSTEMS

2. How do we describe our position on Earth?
The Earth is broken up using a coordinate system that we can use to pinpoint our location
This system uses latitude and longitude

3. Latitude
Lines of latitude run laterally, or from side to side, on the Earth
Lines of latitude describe a location North or South of the Equator

4. Lines of Latitude
Run from 0o at the Equator to 90o North or 90o South
Lines of latitude describe a location North or South of the Equator

5. How were lines of latitude developed?
Lines of latitude are equal to the angle from the center of the Earth
The Equator is equal to 0o as it is straight out from the center of Earth

6. Degrees of Latitude
Each degree of latitude is divided into 60 minutes, each minute, 60 second
For example, 44o 32’ 5” N

7. Latitude and the North Star (Polaris)
The altitude, or angle to, Polaris is equal to the observer’s latitude
This is true only in the Northern Hemisphere because that is where Polaris is visible

8. Finding Polaris
Polaris is a part of the Little Dipper

9. Old-Fashioned GPS
The astrolabe allowed explorers to check their latitude traveling across the Atlantic

10. NYS Latitude and Longitude
Can be found on this reference table

11. Longitude
Lines of longitude run vertically on our globe and converge at the North and South Poles
Coordinates are written (Latitude, Longitude)
Example: (43o N, 77o W)

12. Prime Meridian
The creation of longitude is very similar to that of latitude. It measures the degrees outward away from the center of the Earth up to 180o West and 180o East. 0o is located at the Prime Meridian
Lines of longitude are often referred to as meridians

13. International Dateline
Both 180o W and 180o E meet along the International Date Line, a location where a new day begins and an old day ends

14. Time Zones
Each hour, 15o of longitude is rotated eastward
This becomes a basis for our time zones, each approximately 15o wide

15. NYS Latitude and Longitude
Can be found on this reference table