how are the equator and prime meridian different

How are the Equator and Prime Meridian different?  Do you ever feel confused when you look at those horizontal and vertical lines on a globe or map? You are not alone!

Many people often find it difficult to understand those crisscrossing lines.

By digging deeper, you will realize that those lines actually represent the Equator and Primer Meridian.

And that brings them to another question, “How are the Equator and Prime Meridian alike and different?”

The Equator divides the planet into the Southern and Northern Hemispheres at 0 degrees latitude, whereas the Prime Meridian separates them at 0 degrees longitude.  

About the Equator and Prime Meridian

about the equator and prime meridian

There is a grid of lines drawn onto globes, atlases and world maps.

The geographical grid provides a way to easily and accurately communicate where places are on Earth.

The geographical grid comprises carefully placed horizontal and vertical lines.

The vertical lines that meet at the poles are the lines of longitude but are referred to collectively as the meridians. One, the Prime Meridian is especially important.

The horizontal lines circling globes and drawn onto maps are the lines of latitudes.

One is often called the ‘Great Circle’ and is on Chinese maps that date back to 500 BCE. We know it as the Equator. 

An Important Thing to Know

Most people think any location along the Equator is very hot and typically it is, although there is one spot exactly on the Equator that has permanent snow.

This snowcapped volcanic mountain peak in Ecuador is named Cayambe and the Prime Meridian cuts straight through it. 

How are the Equator and Prime Meridian Different or Alike?

equator prime meridian differences similarities

The Equator splits the Earth into equal hemispheres, north and south. The Prime Meridian splits it equally east and west.

The Equator and the Prime Meridian are only conceptual lines mathematically developed by Pythagoras, initially to help with navigation.

Modern GPS uses the same coordinate system today. 

Explaining what are the Equator and Prime Meridian?

explanation of equator prime meridian

The imaginary line, the Prime Meridian, passes through Greenwich at a longitude of 0o.

By the late 19th century 72% of navigational charts were using the Prime Meridian to measure longitude, their distance from the Prime Meridian east or west.

The imaginary line of the Equator runs horizontally halfway between the poles at 0o latitude where the Earth is widest because of a phenomenon named equatorial bulge. 

It is caused by the Earth’s faster rotation at the Equator.

Fact: The rotation is significantly slower nearer the poles, and the end result is an Earth shaped more like a pumpkin than a true sphere.   

More about the Function of the Equator and Prime Meridian

function equator prime meridian

Both lines serve as zero starting points on the geographical grid and by giving each line a value, any location can be plotted using a fixed point.

Both latitude and longitude measurements are angles and despite the Earth being only almost spherical, it can be equally divided into 360 degrees using arcs.

The distance between the longitudes and latitudes is further divided into smaller minutes and seconds to aid the coordinate system’s accuracy.

Latitude is found by connecting two lines and measuring the angle between them using a fixed line from the Equator to the center of the Earth. 

Division of Hemispheres

For geographical purposes the Earth is described as having four hemispheres:

  • The northern and southern
  • The eastern and western
division of hemispheres

The line of 0o latitude, the Equator, divides Earth into the Northern and Southern Hemispheres. 

Each hemisphere has a different climate because the Earth tilts towards and away from the sun through the seasons.

In the Northern Hemisphere, summer is from June through September but in the Southern, summer begins in December and ends in March.

Fact: The arbitrary line of the prime meridian, or 0o longitude and the International Date Line at 180o longitude, divides Earth into the Eastern and Western Hemispheres.  

More about Differences Between the Equator and Prime Meridian 

equator and prime meridian differences

Astronomically, an Equator is the great circle of a celestial sphere with its plane perpendicular to the earth’s axis.

The Equator doesn’t shift or move, so its representation was recognized on maps 2500 years old.

The Prime Meridian is a manmade device, with its position chosen at the International Meridian Conference in 1884.

Let’s talk about some major differences between the Equator and Prime Meridian:


equator and prime meridian orientation

At first glance, the difference between the imagery lines of the Equator and the Prime Meridian is one of orientation.

The Equator runs horizontal and the Prime Meridian vertical, both as part of the geographical grid.

The grid existed on a map created by Eratosthenes in the 3rd century BCE.

And five centuries later, Ptolemy worked on refining its accuracy by using curved lines of latitudes to compensate for the spherical shape of the Earth.

He realized that for a map to be useful, it needed to reference locations on the grid accurately. His prime meridian passed through the Canary Islands off Africa

Geographical Significance

Hemispheres, while the Prime Meridian divides it into Eastern and Western Hemispheres

The Equator represents a real geographical divide between the climate of the cooler Northern Hemisphere and the warmer Southern.

geographical significance

In contrast, the Western and Eastern Hemispheres have few differences.

The Northern and Southern differ primarily in the ratio of land available to water.

Being 81% water there is less land and so fewer people live in the Southern Hemisphere, only around 12% of the world’s population.

The remaining 88% live in the Northern Hemisphere, which has 67% of the Earth’s total land mass.

In the Northern Hemisphere, the density of the population and its associated activity has resulted in higher levels of pollution. 

Fact: Regions near the Equator have a tropical climate while those near the Prime Meridian can vary. 


equator temperature

Along the Equator temperatures tend to stay near constant around, 88o F. Although with hardly any seasonal tilt, the seasonal variations are minimal.

There are changes in humidity and rainfall so conditions are described as either wet or dry rather than warm or cold.

Without the Earth tilting as much, the position of the Equator relative to the sun barely changes over the course of the year.

This is unlike the Prime Meridian’s distance which varies because of the planet’s Equatorial bulge and rotational tilt.

The Prime Meridian is over 12,000 miles long, and there are many temperature fluctuations along its route. 

Length of the Equator and Prime Meridian

length of equator and prime meridian

The Equator is the longest of five main circles of latitudes covering 24,855 miles, the circumference of the Earth at its widest point. 

Meridians are typically measured in degrees.

Although the line of the Prime Meridian stretches from pole to pole through three continents and 8 countries, it does not circle the earth’s circumference at a full 360o, only halfway, making its length half the circumference of the earth.

 At 180o, the Prime Meridian becomes the Antemeridian, exactly opposite on the other side of the Earth.

This meridian is the international date line, chosen because it crosses the open waters of the Pacific. 

Importance of the Equator and Prime Meridian in Geography 

significance equator prime meridian geography

Besides acting as a convenient reference point, the Equatorial zone is essential for the health of the planet.

It covers almost 6% of the Earth from 0o to 10o north and south as a diverse band of vegetation wrapping the planet.

The dense vegetation absorbs vast amounts of carbon dioxide and exhales huge amounts of oxygen refreshing the atmosphere.

Initially there was debate around where to establish the Prime Meridian. Until 1884, everyone managed using local time.

Fact: Even with the Equator as a fixed-point, sea-borne navigators relied on the sun and the stars to navigate east or west. 

An Important Consideration

There was the political question of borders and it was suggested placing it at 20o would avoid splitting the lucrative colonies of West Africa.

Greenwich was decided because their standardized time would have the best positive impact on the rapidly advancing steam powered transportation and manufacturing industries, which it did. 


How are the Equator and Prime Meridian different?

The Equator and the Prime Meridian are two different lines that signify different things and have different orientations and geographic significance.

The Equator, an imaginary line halfway between the North and South Poles, divides the Earth’s surface into the northern and southern hemispheres.

However, the Prime Meridian divides the Earth into the eastern and western hemispheres.

Because of this, while both function as reference lines in our geographical coordinate system, they designate different axes within it.