Scale Turn to TB pp Put in your notes: Definition of scale Provides a way of depicting, in reduced form, all or part of the world The level of detail and the amount of area covered on a map depend on its scale. Cartographic (or map) scale=ratio of distances on the Earth Observational or methodological scale =the level(s) of analysis used in a specific project or study; they go from small scale (level of the body) to large scale (global level) Large v. small scale Large scale=large amount of detail, small area Small scale=small amount of detail, big area Practice with Scale 5 volunteers! Put the maps in order smallest to largest scale Map Projections Transferring information from the spherical, or ball-shaped, surface of Earth onto a flat piece of paper is called projection. A globe, a spherical model of Earth, accurately represents the shapes and locations of the continents. But if a globe were cut in half and each half were flattened out into a map, the result would be wrinkled and torn. The size, shape, and relative location of land masses would change. Projection is a major challenge for cartographers. Every map has some sort of distortion. The larger the area covered by a map, the greater the distortion. Features such as size, shape, distance, or scale can be measured accurately on Earth, but once projected on a flat surface only some, not all, of these qualities can be accurately represented. For example, a map can retain either the correct sizes of landmasses or the correct shapes of very small areas, but not both. Source: National Geographic 4 Types of Distortion 1.Shape- refers to geometric shapes of objects on the map 2.Size (area)- relative amount of space taken on the map by landforms or objects on the map 3.Distance- represented distance between objects on a map 4.Direction- degree of accuracy representing cardinal directions (North, south, east and west) and intermediate directions (northwest, southwest, northeast, southeast) All four proporties cannot be accurately represented, the cartographer (mapmaker) must decide which aspects are more important What is the difference between these two projections? Mercator Useful: looking at equator, where distortion is minimized; nautical navigation Distortion= area (size) distortion; size is distorted especially at the poles, direction is true Robinson Use: for location, general reference Distortion= all four categories are slightly distorted Winkel Tripel Use: due to minimal distortion it is well suited for general purpose mapping, rarely used to map anything smaller than the whole planet Distortion= shape (especially at the poles), distance Peters Projection Peters Use: currently in limited use, but helps to promote better understanding of size and location Distortion= size is true, shape is distorted, location is true Isoline Map