Map Projections

Distances between Washington D.C., USA and Kabul, Afghanistan:

• Mercator: 10,112.12 miles
• Stereographic: 9,905.71 miles
• Equidistant Conic: 7,083.97 miles
• Azimuthal Equidistant: 8,348.19 miles
• Eckert IV: 7,862.56 miles
• Cylindrical Equal Area: 10,106.32 miles

Map projections help portray a geographic area in a way that would fit the purpose of the graph. Different map projections can cater to help show true direction, shape, distance, or area. However, the major fault of these map projections is that not all of these features can be depicted simultaneously. Above I have pictured six different type of map projections, all of which cater to a specific need. Although these are six different types of projections, they are just the few of many map projections that are under constant revision. 

Conformal maps help with proper display of angles. This feature means that direction is always preserved on the map. Area, shape, and distance are not preserved in Mercator maps. In fact, these features are distorted to help create a neat, rectangular shaped map which is useful for making it easy for visuals. Most of the distortions are at the poles and the most accurate distances are close to the equator. In Stereographic maps, distances are true from the center point and the scale increases as you move away from the center of the map. This map is useful for solving spherical geophysical problems and for maps of the polar regions.

Equidistant maps show true scale between two points. Equidistant Conical projections are useful for displaying regions in the mid-latitudes as it utilizes two standard parallels. Just like the last two map projections, distortion also increases as we move away from the two standardized parallels. Distances are also true along the standardized regions but change as the distortion increases. For Azimuthal Equidistant maps, both direction and distance are true from the center of the point projection. As long as the lines from two points run through the center point, the distance is true. Therefore, as you can compare the distances, the distance between Washington D.C. and Kabul are distorted because they do not run between the center point.

Equal Area maps distort the distances of the oceans to ensure that the continents are distorted as little as possible. The Eckert IV map is very different because it is neither a circle or rectangular map. The curved sides and variation of distances between lines help with reducing polar distortions. Cylindrical Equal Area maps compress the distances at the poles. The polar regions of the map are therefore distorted in shape and may not always be clear to individuals. However the distances at both the poles at two latitudes that lie north and south of the equator. The positive thing about having multiple standard parallels is that distortion of area are minimized at these lengths.