Oncemore, as per the previous lab exercises, the obvious pitfalls, perils and significance demonstrate themselves. The obvious pitfalls; if a map’s purpose is misunderstood, the geographic information within can be used greatly misused. The basic instance of this is with that most ubiquitous of map projections: the Mercator. One would not use a Mercator map to discover land-area disparities between Greenland and the whole continent of Africa, for the intent of a Mercator projection is to preserve angles for navigation. That this common misrepresentation can not only jeopardize knowledge for action, but also impede upon cartographic misunderstanding is dangerous in a world so dependent upon self-motivated research (ie; Wikipedia). If a flashed glance over a map is taken without careful care to the cartographic projection in use, one can have a drastically skewed worldview. Of course, on the flip side of that heavy coin we find that if used with appropriate understanding to the conventions of projection, we can navigate from point to point, measure distances appropriately and compare areas sufficiently well as to properly navigate the world in two dimensions.
Within photography, the notion of distortion can completely change how one views a work of art or a piece of passively collected survey data. The same is true upon the surveying of a map. The standard by which, in this lab, we can measure obvious distortion is within the distances between two fixed points, each with their own fixed coordinates. When viewing the range of these distance values, using several different types of projections (the types being equidistant, equal area and conformal projections) we can see a disparity of up to 5000 miles (at least betwixt the Fuller and Mercator Projections). That this distortion is confusing to the young students of geography is but a challenge; to someone peering a map with a fleeting glance and little knowledge distortions may be confusing. Especially confusing are Equal Area Maps. These maps distort the shapes of land masses horrendously yet preserve relative areas. For instance, on an equal area Hammer Projection the Eastern Coast of Greenland looks tremendously arced Westward (relative to the North Pole) when indeed it follows a fairly passive N to SW taper in reality. This projection, however, avoids turning Greenland into a monster continent as the Mercator Projection does. That these questions arise are the primary pitfall of the diversity of map projections.
However, the genius of potential misunderstanding is invariably found in the reciprocal level of difficulty; the more sophisticated the map projection, the more useful it may be. For instance the Fuller Projection below uses triangles to divide the world into sections. This method, although it does not use a conventional ovular or rectangular structure preserves both equal area projection in addition to preserving the angles/native shapes of the land masses. Its non conventional usage of distinct shapes shows itself to be useful also in projecting a distance of 6385 Miles, which is only slightly higher than the average distance measured in my six projections (assuming my 6 projections are a random sample of the available projections); making it a likely contender for the best overall projection.
The map projections which we use in this lab, that I find to exemplify both the pitfalls and potential diversity of map projection usage (whether in GIS or not) are indeed the equidistant projections; Cylindrical and Sinusoidal. These maps may demonstrate that distances are preserved in equal proportion within a map yet they do not do anything more productive than their very esoteric task. They demonstrate the key crux in why certain types of projections are indeed useful and how they can be unfortunately misconstrue the readers’ own mental map of how they see the world by meddling in the basic elements of area and angles to produce an esoteric product.