Published on August 5, 2014
C. Map Scale 1. The first decision a cartographer faces is how much of Earth's surface to depict on the map. 2. The level of detail and the amount of area covered on a map depend on its map scale. Map scale is presented in three ways: a. A ratio or fraction shows the numerical ratio between distances on the map and Earth's surface. A scale of 1:24,000 or 1/24,000 means that 1 unit on the map represents 24,000 of the same unit in inch, centimeter, foot, finger length on ground. b. A written scale describes the relationship between map and Earth distances in words. "1 inch equals 1 mile" c. A graphic scale usually consists of bar kine marked to show distance on Earth's surface. D. Projection 1. Earth is very nearly a sphere and is therefore accurately presented with a globe. However, a globe is an extremely limited tool with which to communicate information about Earth's surface. 2. The scientific method of transferring locations on Earth's surface to a flat map is called projection. Four types of distortion can result: a. The shape of an area can be distorted, so that it appears more elongated or squat than in reality. b. The distance between two points may become increased or decreased. c. The relative size of different areas may be altered, so that one area may appear larger than another on a map but is in reality smaller. d. The direction from one place to another can be distorted. E. Geographic Grid 1.. The geographic gird is a system of imaginary arcs drawn in a grid pattern on Earth's surface. the location of any place on Earth's surface. The location of any place on Earth's surface can be described precisely by meridians and parallels, two sets of imaginary arcs drawn in a grid pattern on Earth's surface. a. A meridian is an arc drawn between the North and South poles. The location of each meridian is identified on Earth's surface according to a numbering system known as longitude. b. A parallel is a circle drawn around the globe parallel to the equator and at right angles to the meridians. c. Latitude: the numbering system to indicate the location of a parallel is called latitude.