1. Lines of Latitude and Longitude
The Global Grid

2. In your notes write a paragraph about the different parts of a map.
The Global Grid
In your notes write a paragraph about the different parts of a map.

3. The Global Grid
Why is there time?
Type 1 Writing
5 lines
3:14

4. The Global Grid
Why do we have seasons?
Type 1 Writing
4 lines
2:38

5. The Global Grid
We talked about grid systems on maps and said that some maps use coordinates systems of numbers and letters.
Most maps, however, use a system of lines called latitude and longitude.
Latitude and longitude gives us the ability to accurately chart any point on the earth.
It’s like an imaginary piece of graph paper put over the planet.

6. Lines of Longitude
Lines of longitude are really half circles drawn from the north pole to the south pole.
They begin at a line called the Prime Meridian and measure east and west until they meet in the Pacific ocean at 180°. They are also called Meridians

7. Lines of Longitude
These lines tell us about Direction (east and west), Location (where we are on the globe), and Time (every 15° is the center line of a new hour).

8. Special Lines of Longitude
There are two special lines of longitude:
The Prime Meridian: This is the name of the line that divides the earth into eastern and western hemispheres. It is the beginning line of longitude, and it is given the measurement of 0° long. This line is sometimes called the Greenwich Meridian because it passes through Greenwich, England.

9. Greenwich Meridian
Even though it looks like it should be pronounced like the Witch is Green, it is not pronounced that way. Even though it should sound like SAND-WICH, it doesn’t.
It is pronounced GREN-ITCH, as if you had an itchy gren (and we all know how irritating that can be!)
Look at the word and pronounce it with me:
GREENWICH, GREENWICH, GREENWICH

10. Whereas, in order to the finding out of the longtitude of places for perfecting navigation and astronomy, we have resolved to build a small observatory within Our Park at Greenwich... Charles II 1675
The Royal Observatory is also the source of the Prime Meridian of the world, Longitude 0° 0' 0''. Every place on the Earth is measured in terms of its distance east or west from this line. The line itself divides the eastern and western hemispheres of the Earth – just as the Equator divides the northern and southern hemispheres.

11. The Royal Observatory in Greenwich, England – home of the Prime Meridian.

12. A GPS on the Prime Meridian outside the Greenwich Observatory
A GPS on the Prime Meridian outside the Greenwich Observatory. Notice the position.

13. A laser reading at 0°Longitude
A laser reading at 0°Longitude. The Prime Meridian passes through the middle of this building

26. Why Longitude Matters
By 1700, finding latitude at sea was routine and fairly accurate.
But finding longitude was mostly guesswork. Astronomers thought the answer to finding longitude lay in observing the skies. Others thought the solution was a good seaworthy clock, but no such clock existed.
After an outpouring of ideas and generations of work, both a good clock and a good sextant for observations were invented. These instruments revolutionized position-finding at sea.

27. Special Lines of Longitude
The International Date Line: This line for the most part follows the 180° long. Line where east meets west in the Pacific Ocean. As you cross the line the day changes.

28. Lines of Latitude
Lines of Latitude are really circles drawn around the globe. They begin at the equator which is 0° latitude. They measure north and south to the poles.
These lines are sometimes called parallels.

29. Special Lines of Latitude
The Equator: O° lat. Divides the earth into northern and southern hemispheres. It tells us direction (north and south), and location. The sun shines directly on the equator on 21 March and 21 September.

30. Special Lines of Latitude
The Tropic of Cancer: 23 .5° N. The point where the sun shines directly on 21 June.
The Tropic of Capricorn: 23 .5° S. The point where the sun shines directly on 21 December.

31. Special Lines of Latitude
The Arctic Circle: 66.5°N.
The Antarctic Circle: 66.5° S.
Between these circles and the poles (90°) the climate is very cold all year long. This is called the polar region, or high latitudes.

32. Special Lines of Latitude
The area between the tropics of Cancer and Capricorn is called the Tropical Region. The climate is very warm all year. This region is also called the low latitudes.
The Temperate Region lies between 23.5 and The climate is seasonal because there is wide range of temperatures. The seasons are opposite in the north and south temperate regions.

34. Coordinate
Distance
Equator
Global
Great Circle
Grid
International Date Line
Latitude
Longitude