Chapter 1 Basic Concepts

HOW DO GEOGRAPHERS DESCRIBE WHERE THINGS ARE? Key Issue 1

Maps Maps: allow people to think spatially. Very important tool for geographers. 2-D or Flat Scale Model of the earth’s surface. Cartography: science of map making. Computers give us contemporary images. Maps: aid us to find shortest route. Maps identify relationships. Maps: identify human activities. Maps identify information such as religion, language, population.

Early Map Making Earliest maps were navigation devices. Eratosthenes ( B.C.); Ptolemy ( AD) were first known geographers to use maps. Maps created by information collected by merchants. Later maps became more fanciful than informational. Mapmaking was re- discovered during the Age of Exploration. Explorers required accurate maps to navigate to routes around the world. German cartographer Martin Waldseemuller produced the first map of America. By 17 th century most maps accurately displayed the outline of most continents.

Contemporary Map Making Maps are primarily tools of communication. Geographers use maps to display geographic information.

Map Scale How much of the earth’s surface should a cartographer depict on a map? The level of detail and the amount of area covered depends on the map scale. Ratio or fraction: numerical ratio between distances on the map and the earth’s surface…. Example 1:24,000 means one unit of measurement represents 24,000 of the same on the earth’s surface. Written scale: relationship between the map and earth distances in words….Example 1 in. = 1 mile. Graphic scale: consist of a bar line marked to show distance on the earth’s surface.

Projection Most accurate representation of the earth is with a globe. However, difficult to use and study geographic elements with a globe. Most maps are flat, but that presents problems…distortion. The scientific method of transferring locations on the earth to a flat surface is projection. 4 types of Distortion 1. Shape 2. Distance 3. Relative Size 4. Direction Equal Area Projections minimize all 4 areas the most. Types of Projections Mercator Goode Homolosine Robinson

Geographic Grid The grid system is a system imaginary arcs drawn in a grid pattern on the earth’s surface. Meridian’s: north and south… or lines of longitude. Parallel’s: circles drawn around the earth parallel to the equator or lines of latitude. Prime Meridian: zero degrees longitude….opposite of it is 180 degrees longitude. Equator: zero degrees latitude. North and South poles are at 90 degrees north and south. Latitude and longitude are used to determine Absolute Location. International Date Line: is at 180 degrees longitude.

Contemporary Tools GIScience: geographic information science: development and analysis of data about the earth acquired through satellite information. Remote sensing satellites scan the earth’s surface and transmits the information to a receiving station on Earth. GPS: Global Positioning System: pin points precise position. Used for navigation. GPS for aircraft, boats, cars, etc. How does it work? GIS: Geographic Information System: captures and stores geographic data. More accurate that GPS.