Lab 4 part 2

       The reason we use map projections is because some surfaces that are not flat, i.e. a sphere, need to be represented in a two dimensional form. This two dimensional form is that of a flat map and projection distorts the image of the three dimensional object so the surface will appear flat. Depending on the function of the map some distortions are acceptable and some are not. So some maps preserve the actual size of the geographic features on the map and distort the traditional square looking maps and some preserve the traditional style by sacrificing the actual shapes of the features and distances. We can compare the styles and their accuracy by measuring distances on the maps from one city to another, in this case from Washington D.C. to Baghdad, Iraq which is 9977 kilometers apart.

      The first style of conformal map projection preserves angle and shape. The first type of conformal map is the Mercator map. This map is preserving the shape of the major continents, however it makes the regions of the Antarctic extremely oversized compared to the rest of the continents, as well as Greenland but not to that extent. The distance from D.C. to Baghdad is 13,614 km, which is way over. The second type of conformal map is the Gall Steriographic. It to shows the continent of Antarctica and Greenland over sized however Antarctica is a little smaller this time, the distance between D.C. and Baghdad is much closer to the real figure at 9,565 km, which was a surprise to me.

      The second kind of map projection is the Equal Area map which preserves the area of the features on the Earth. The first style of Equal Area map is the Bonne map. It looks like a giant heart but now the continents are more proportional to each other with Antarctica and Greenland now their regular size. It is however hard to see Australia and surrounding islands but you have a very good view of the northern hemisphere. The distance from D.C. to Baghdad is also closer at 9,345 km. The second style of Equal Area map is the Hammer. The map now resembles what the globe actually looks like in sort of a football shape with all continents visible and comparatively similar. D.C. to Baghdad is over at 11,210 because the areas are equal not the distances.

      The last type of map projection is the Equidistant map. It preserves neither area nor shape but preserves distance over a short area. The first style of Equidistant map is the Equidistant Conic map. This map looks like you took a globe and butterflyed it with a knife and smashed it flat. The map is cut in the Pacific Ocean and leaves a good 45-degree section off. The continent of Antarctica is now greatly oversized again. The distance is now the closest to the real figure at 10,073 km, which is what I would expect. The second style of Equidistant map is the Equidistant Cylindrical map. For some reason this Equidistant map looks almost exactly like the Gall Steriographic map. Its not though because the map seems more stretched vertically. When I looked at the definition on Wikipedia its like they cut the globe up into a tube like shape and then it’s as if they roll it on a flat surface. The distance from D.C. to Baghdad is extremely under at 6,776 km. This could be because these maps are supposed to be good for short distances.