Mapping the world

Mercator projection

How does it work?

Activity 1: Order, from largest to smallest, the following countries: Argentina, Australia, Brazil, China, Greenland and India.

Mercator’s projection preserves angles but distorts areas. In fact, Australia is more than three times bigger than Greenland! Tissot’s indicatrix is a mathematical tool that gives you information about the distortion of the map (the bigger the red circle the more distorted).

Tissot’s indicatrices for the Mercator projection Comparison between the size of Greenland and Australia

Other projections

Activity 3: Classify the following maps according if you think that they preserve the areas, preserve the angles, or both.

Mercator Lambert

Equirectangular or Plate Carrée

Stereographic Azimuthal

Mollweide

Robinson

Geodesics

Activity 4: To fly from São Paulo to Tokyo which of the following places will you be flying over?

a) Canada b) Mexico c) Hawaii d) Argentina

And if you fly from Moscow to Mexico City?

a) United Kingdom b) Spain c) Greenland d) Brazil

Links to more resources

• 
  The Wikipedia page on map projection gives a useful overview with links to further information:
  

• 
  A powerful Java app allowing you to explore many different map projections (if you have difficulty getting the Java to work, email one of us and we can send you instructions):
  

• 
  A website with informal descriptions of the key concepts in cartography – the science of making maps:
  

We hope you have enjoyed our workshops. Please get in touch if you would like to find out more about the topics of these workshops, or if you have any questions about studying maths at university.