|The other half of the global grid system are the meridians of
Meridians of longitude are imaginary lines that run from the North
Pole to the South Pole. A north and south line can be called just
meridian or just longitude. Meridians of longitude are not parallel to
One special meridian is called the Prime Meridian. The Prime
Meridian is the meridian that passes through the town of Greenwich,
England, which is near London.
Longitude measures the distance east and west of the Prime Meridian.
Each meridian is numbered and is measured in degrees (). There are 360
degrees all the way around the Earth. The numbering starts with the
Prime Meridian, which is at zero degree (0).
As you move east from the Prime Meridian, each meridian of longitude
is numbered from 0 to 180 E. As an example, 15 E is the meridian that is
15 degrees to the east of the Prime Meridian.
As you move west from the Prime Meridian, each meridian of longitude
is numbered from 0 to 180 W. As an example, 95 W which is the meridian
that is 95 degrees to the west of the Prime Meridian.
Find the Prime Meridian on the world map. Notice that the Prime
Meridian does not touch the North Pole. In fact, the poles do not appear
on the map. This often happens on world maps. Sometimes when a spherical
object (the Earth) is drawn on a flat surface (a world map), the poles
do not show. The upper left and right corners of the world map show
special round maps showing the North and South Pole areas.
Find the 180 meridian near the east edge (right side) of the world
map. The 180 meridian of longitude is the joining line for the longitude
lines running east and west from the Prime Meridian (0). The 180
meridian of longitude and the Prime Meridian are on opposite sides of
??? Use the world map to help find an answer to these questions.
Trace the Prime Meridian from the south (bottom) to the north (top)
of the map. List the countries that the Prime Meridian runs through (or
just barely touches) from south to north in the spaces provided below.
??? Locate each of the five cities listed below on the world map.
Then identify the meridian of longitude that is closest to the city.
Write the answer in the space provided, and be sure to note if it is
east or west of the Prime Meridian.
|10. Osaka, Japan
|11. Alexandria, Egypt
|12. New Orleans, southern United States
|13. Ottawa, southeastern Canada
|14. Sydney, southeastern Australia
??? Find the 90 E meridian on the world map. 90 E refers to the
meridian that is 90 degrees east of the Prime Meridian. List the
countries that the 90 E meridian runs through from the south to the