1. Latitude & Longitude

2. - using latitude & longitude to determine your position on Earth.
Coordinate System
- using latitude & longitude to determine your position on Earth.

3. Latitude Longitude line running east to west
measures the distance in degrees North and South of the equator.
measured by parallels, because all lines of latitude are parallel.
largest value of latitude is 90°
- Equator – 0°00’ N/S
- North Pole – 90°00’ N
- South Pole – 90°00’ S
- Horseheads, NY – 42°10’N
line running north to south
measures the distance in degrees East and West
of the prime meridian.
All meridian lines meet at the poles and are further apart at the equator. They are not parallel
largest value of longitude is 180°
Prime Meridian – 0°00’ E/W Horseheads, NY – 76°51’ W

4. Latitude
49o
Latitude lines are also called PARALLELS because they run parallel to the equator.

5. Latitude
At night in the Northern Hemisphere, latitude can be determined by measuring the altitude of Polaris (North Star)
40o

6. To Polaris
To Polaris
90°
40°
Horizon
To Polaris
North Pole 0°

7. Longitude Based on the Sun’s Apparent motion through the sky.
How long does it take the Earth to rotate once on its axis?
24 hours
How many degrees does it rotate in this time?
360o
Degrees per hour = 360/24 = 15o/hour

8. Longitude
The distance, in degrees, measured east or west of the Prime Meridian.
Prime Meridian passes through Greenwich, England (Longitude 0o)

9. Measuring Longitude Greenwich Mean Time (GMT) Solar Time – (noon)
what time it is in Greenwich, England
0o line for longitude
Solar Time – (noon)
when the sun reaches it highest altitude in the sky at your location.

10. Measuring Longitude
Remember – the Earth rotates at 15o/hr and that the Sun “appears” to move through the sky at the same rate.
If you know what time it is in Greenwich when it is noon at your location you can calculate you longitude.

11. Measuring Longitude
It was 2:00 pm in Greenwich (GMT) when it was noon at your location (12:00pm)
Time Difference =?
2 hours
2 hours X 15o/hr
= 30o
Your longitude = 30oW
  Earth Rotates from W to E  
Note – If it is NOON your time and GMT = PM, you are WEST of the P.M.
If it is NOON your time and GMT = AM, you are EAST of the P.M.

12. Longitude and Time

13. Longitude and Time

15. Nor th
South

16. Writing Latitude & Longitude
Latitude (N or S) comes FIRST, followed by the longitude (E or W)
45o N, 33o E
85o S, 123o W
95o S, 47o E
Anything WRONG here!!

17. There are 60 minutes in one degree
Latitude and Longitude are measure in DEGREES AND MINUTES
Xo Y ‘
Degrees Minutes
There are 60 minutes in one degree
Examples: Latitude  30o45’ N
Longitude  46o12’ E