The Equator and Prime Meridian are the two main reference lines used to describe locations on Earth. The Equator circles Earth halfway between the North Pole and South Pole, dividing the planet into the Northern and Southern Hemispheres. The Prime Meridian runs from pole to pole through Greenwich, England, dividing Earth into the Eastern and Western Hemispheres.
Together, they create a starting point for the coordinate system used on globes, maps, GPS, and navigation tools.
Latitude measures how far north or south a place is from the Equator, while longitude measures how far east or west it is from the Prime Meridian. These measurements are written in degrees because Earth is a sphere and locations are measured using angles from its center. When latitude and longitude are used together, they form a precise global address for any place on Earth.
Understanding these lines helps students read maps, compare regions, track travel routes, and connect geography with geometry and Earth science.
Key Facts
- The Equator is located at 0° latitude.
- The Prime Meridian is located at 0° longitude.
- Latitude ranges from 0° to 90° north or south of the Equator.
- Longitude ranges from 0° to 180° east or west of the Prime Meridian.
- Coordinates are written as latitude, longitude, such as 40° N, 75° W.
- The Equator divides Earth into the Northern Hemisphere and Southern Hemisphere, while the Prime Meridian divides Earth into the Eastern Hemisphere and Western Hemisphere.
Vocabulary
- Equator
- The Equator is the imaginary circle around Earth at 0° latitude, halfway between the North Pole and South Pole.
- Prime Meridian
- The Prime Meridian is the imaginary line at 0° longitude that runs from the North Pole to the South Pole through Greenwich, England.
- Latitude
- Latitude is the angular distance north or south of the Equator, measured in degrees.
- Longitude
- Longitude is the angular distance east or west of the Prime Meridian, measured in degrees.
- Hemisphere
- A hemisphere is one half of Earth, such as the Northern, Southern, Eastern, or Western Hemisphere.
Common Mistakes to Avoid
- Switching latitude and longitude is wrong because latitude tells north or south position, while longitude tells east or west position.
- Writing coordinates in the wrong order is wrong because map coordinates are usually written as latitude first, then longitude.
- Thinking the Equator runs from pole to pole is wrong because the Equator circles Earth east to west around its middle.
- Assuming the Prime Meridian is the same as the International Date Line is wrong because the Prime Meridian is 0° longitude, while the International Date Line is near 180° longitude.
Practice Questions
- 1 A city is located at 30° N, 90° W. Is it north or south of the Equator, and east or west of the Prime Meridian?
- 2 Point A is at 15° S and Point B is at 40° S. How many degrees of latitude apart are they?
- 3 A ship sails from 10° W longitude to 20° E longitude while staying on the Equator. Explain why it crosses the Prime Meridian and how its hemisphere changes.