MERCATOR PROJECTION: ADVANTAGES, DISADVANTAGES AND EXAMPLES - GEOGRAPHY - 2025

The Mercator projection is a cylindrical map projection that represents the entire Earth's surface. It was developed by Gerardus Mercator in the 16th century, in 1569.

This map projection has been widely criticized for the fact that it distorts shapes as it approaches the poles, making land masses appear larger than they actually are.

Proponents of Mercator note that the cartographer did not create this projection with the intention of teaching geography, but rather to facilitate exploration through navigation.

This aspect differentiates the Mercator projection from other previous projections. The maps that had been made so far were descriptive and focused mainly on the representation of relief and water courses. Mercator's proposal was rather functional.

Today the Mercator projection continues to be one of the most widely used. In fact, the global position services of Google, Bing, OpenStretMaps and Yahoo are based on this type of map projection.

History

During the 16th century, information regarding trade routes and geography constantly increased every day.

For this reason, navigators, explorers, and traders needed more accurate maps. This is how the cartographer and geographer Gerardus Mercator (1512-1594) decided to develop the cylindrical projection that bears his name.

How does the Gerardus Mercator projection work?

To get an idea of ​​how the Mercator projection works, we just have to imagine that we have a translucent globe.

This balloon will be wrapped in a paper cylinder, so that the equator is the only point of contact between the balloon and the cylinder.

As it is a projection, the intervention of light is necessary. To carry out the Mercator projection, the light source must be located at the Equator, on the opposite side to the point of contact between the globe and the paper.

In this way, the light will project the figure of the land masses onto the paper cylinder. The shapes closest to the Equator will be projected almost perfectly. However, as they move away from parallel, the shapes become distorted and enlarged. For this reason, it is observed that Greenland is the size of Africa when in reality it is somewhat larger than Mexico.

Advantages of the Mercator projection

Explore the world

Before the Mercator projection existed, there were already maps that showed the entire extent of planet Earth.

However, this was the first that provided people with the means to explore and navigate the seas. Mainly, this projection is useful for plotting routes with constant heading in a straight line.

In addition to creating a projection, Mercator published a geometric formula that corrected the distortion presented on his map. These calculations allowed mariners to transform the projection measurements into degrees of latitude, facilitating navigation.

Like any flat representation of the Earth, the Mercator projection is distorted. The globe is the only faithful representation of the earth's surface.

Despite this, the fact that these are so small makes them impractical for navigation. For this reason, the Mercator projection is still preferred.

The calculations of this projection are simpler than those of other projections

The math behind the Mercator projection is much simpler than other current projections. For this reason, online mapping services prefer their use.

The Google Maps, Bing Maps and OpenStreetMaps applications are based on the Mercator projection.

Keeps the scales

The Mercator projection is proportional. This means that to compensate for the north-south (pole-to-pole) distortion, an east-west distortion is also introduced.

Other projections can make a square building look rectangular, because the distortion exists in only one direction.

In contrast, being proportional, the distortion generated by Mercator does not make objects look more elongated or flattened, but simply larger.

This is another reason why web mapping services use this type of projection and not others.

Angles are represented correctly

The Mercator projection has the property of representing the angles as they are. If there is an angle of 90 ° in the real plane, the projection will show an angle of the same amplitude.

This is another reason why Google Maps and other similar applications prefer Mercator over other projections.

Disadvantages

Distorts the land surface

As the Mercator projection moves away from the equator, the representation of the earth's surface is distorted. This distortion makes the shapes at the poles look larger than they really are.

The Mercator projection shows that Greenland is the size of Africa, Alaska is bigger than Brazil, and Antarctica is an infinite expanse of ice.

In reality, Greenland is the size of Mexico, Alaska's territory is 1/5 that of Brazil, and Antarctica is slightly larger than Canada.

As a result, commercial maps for educational purposes do not usually use the Mercator projection, so as not to cause problems in the learning process of students. However, they are still used in the representation of areas near Ecuador.

The polar zones are not represented

Because the Mercator projection is based on a cylinder, it is difficult to represent the polar zones of planet Earth. For this reason, the poles are not included in this type of map projection.

Mercator projection examples

One of the best examples of Mercator projection is Google Maps. This is a global positioning software developed in 2005.

Bing Maps and OpenStreetMaps are other web mapping services that use the Mercator projection.

Articles of interest

Homolographic projection.

Peters projection.

Azimuthal projection.

Types of projections.

References

1. Cylindrical Projection: Mercator. Retrieved on October 13, 2017, from gisgeography.com
2. Mercator projection. Retrieved on October 13, 2017, from wikipedia.org
3. Mercator projection (cartography). Retrieved on October 13, 2017, from britannica.org
4. Mercator projection. Retrieved on October 13, 2017, from geography.hunter.cuny.edu
5. Mercator projection. Retrieved on October 13, 2017, from dictionary.com
6. Mercator projection. Retrieved on October 13, 2017, from merriam-webster.com
7. Mercator Projection v. Gall-Peters Projection. Retrieved on October 13, 2017, from businessinsider.com
8. Mercator's Projection. Retrieved on October 13, 2017, from math.ubc.ca