Episode 88: Cartography and Earths Seasons

Cylindrical Projections

Cylindrical projections, like the Mercator projection, are widely known for their navigational utility but also for their significant distortions. James Fodor explains that while these projections preserve shapes, they dramatically inflate areas near the poles, making regions like Greenland appear much larger than they are 1. This distortion is particularly misleading in the northern hemisphere, where more land is present near the poles.

The Mercator projection, as I said, is a type of cylindrical projection, so it distorts the poles most severely in some sense.

--- James Fodor

Despite these inaccuracies, the Mercator projection remains popular due to its historical use in navigation, where straight lines on the map correspond to constant compass bearings 2.

   

Conic Projections

Conic projections offer a different approach by projecting the Earth's surface onto a cone, which is particularly useful for mid-latitude regions. James Fodor describes how these projections minimize distortion where the cone touches the Earth, making them ideal for areas between the equator and the poles 3. This method is less effective at the equator or poles but provides a balanced representation for regions like Europe and North America.

These conical projections can be useful for projecting mid latitudes, because the place of the least distortion tends to be neither on the equator nor at the pole.

--- James Fodor

The trade-off is that as the cone moves away from the Earth's surface, distortion increases, affecting the accuracy of the map 4.

   

Special Projections

Special projections, such as azimuthal and interrupted projections, provide unique solutions for specific mapping challenges. James Fodor highlights azimuthal projections, which are useful for accurately depicting polar regions by placing a circular plane over the poles 2. This method reduces distortion at the poles but increases it towards the equator.

An azimuthal or a plane projection, which is instead of placing a cylinder around the equator, it's kind of like the plane or azimuthal projection is like putting a dish, or essentially, it's a two dimensional circle at some point on the surface of the earth.

--- James Fodor

Interrupted projections, on the other hand, unfold the Earth's surface, preserving the shape and size of continents but creating gaps over oceans, which can appear less aesthetically pleasing 3.