1. A map (history of maps) is a visual representation of an area - a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes.
    
2. Cartography, or map-making, is the study and practice of crafting representations of the Earth upon a flat surface. One who makes maps is called a cartographer.
    
3. Road maps are perhaps the most widely used maps today, and form a subset of navigational maps, which also include aeronautical and nautical charts, railroad network maps, and hiking and bicycling maps. In terms of quantity, the largest number of drawn map sheets is probably made up by local surveys, carried out by municipalities, utilities, tax assessors, emergency services providers, and other local agencies. Many national surveying projects have been carried out by the military
    

   Click above for detailed Oklahoma road map (1.5 M pdf file)

(maps & globes, 6 min)

1. Map projections are attempts to portray the surface of the earth or a portion of the earth on a flat surface. Some distortions of conformality, distance, direction, scale, and area always result from this process. Some projections minimize distortions in some of these properties at the expense of maximizing errors in others. Some projection are attempts to only moderately distort all of these properties.
    
2. Map projections fall into four general classes.
    
   • Cylindrical projections result from projecting a spherical surface onto a cylinder.
   • Conic projections result from projecting a spherical surface onto a cone.
   • Azimuthal projections result from projecting a spherical surface onto a plane.
   • Miscellaneous projections include unprojected ones such as rectangular latitude and longitude grids and other examples of that do not fall into the cylindrical, conic, or azimuthal categories
   
    
3. Examples of map projections
    
   • The Mercator projection has straight meridians and parallels that intersect at right angles. Scale is true at the equator or at two standard parallels equidistant from the equator. The projection is often used for marine navigation because all straight lines on the map are lines of constant azimuth.
     

   • The Miller projection has straight meridians and parallels that meet at right angles, but straight lines are not of constant azimuth. Shapes and areas are distorted. Directions are true only along the equator. The projection avoids the scale exaggerations of the Mercator map.
     

   • The Universal Transverse Mercator (UTM) projection is used to define horizontal, positions world-wide by dividing the surface of the Earth into 6 degree zones, each mapped by the Transverse Mercator projection with a central meridian in the center of the zone. UTM zone numbers designate 6 degree longitudinal strips extending from 80 degrees South latitude to 84 degrees North latitude. UTM zone characters designate 8 degree zones extending north and south from the equator.
     

   • The Mollweide projection, used for world maps, is pseudocylindrical and equal-area. The central meridian is straight. The 90th meridians are circular arcs. Parallels are straight, but unequally spaced. Scale is true only along the standard parallels of 40:44 N and 40:44 S.
     

   • The Eckert projection, used for world maps, is a pseudocylindrical and equal-area. The central meridian is straight, the 180th meridians are semi-circles, other meridians are elliptical. Scale is true along the parallel at 40:30 North and South.
     

   • The Robinson projection is based on tables of coordinates, not mathematical formulas. The projection distorts shape, area, scale, and distance in an attempt to balance the errors of projection properties.
     

   • The Polyconic projection was used for most of the earlier USGS topographic quadrangles. The projection is based on an infinite number of cones tangent to an infinite number of parallels. The central meridian is straight. Other meridians are complex curves. The parallels are non-concentric circles. Scale is true along each parallel and along the central meridian.
     

   • The Albers Equal Area Conic projection distorts scale and distance except along standard parallels. Areas are proportional and directions are true in limited areas. Used in the United States and other large countries with a larger east-west than north-south extent.
     

   • The Azimuthal equidistant projection is sometimes used to show air-route distances. Distances measured from the center are true. Distortion of other properties increases away from the center point.
     

   • The Orthographic projection is used for perspective views of hemispheres. Area and shape are distorted. Distances are true along the equator and other parallels.
     

   • Stereographic projections are used for navigation in polar regions. Directions are true from the center point and scale increases away from the center point as does distortion in area and shape.
     

   • Unprojected maps include those that are formed by considering longitude and latitude as a simple rectangular coordinate system. Scale, distance, area, and shape are all distorted with the distortion increasing toward the poles.
     

1. Latitude (shown as a horizontal line) is the angular distance, in degrees, minutes, and seconds of a point north or south of the Equator. Lines of latitude are often referred to as parallels.
    
2. Longitude (shown as a vertical line) is the angular distance, in degrees, minutes, and seconds, of a point east or west of the Prime Meridian (Greenwich). Lines of longitude are often referred to as meridians.
      
3. Distance Between Lines
    
   • Degrees - If you divide the circumference of the earth (approximately 25,000 miles) by 360 degrees, the distance on the earth's surface for each one degree of latitude or longitude is just over 69 miles, or 111 km.

     Note: As you move north or south of the equator, the distance between the lines of longitude gets shorter until they actually meet at the poles. At 45 degrees N or S of the equator, one degree of longitude is about 49 miles.

   • Minutes and Seconds - For precision purposes, degrees of longitude and latitude have been divided into minutes (') and seconds (''). There are 60 minutes in each degree. Each minute is divided into 60 seconds. Seconds can be further divided into tenths, hundredths, or even thousandths.
      
   • Degrees, minutes, and seconds were once the only way of expressing latitude and longitude. Because of electronic GPS systmes, it is now common to express them using decimal degrees.
     The location of the White House in Washington, DC is:

     Decimal Degrees	Deg:Min:Sec
     Lat: N 38.898648o	38o 53' 55.133" N
     Lon: W 77.037692o	77o 02' 15.691" W

     The location of Crescent Oklahoma is:

     Decimal Degrees	Deg:Min:Sec
     Lat: N 35.93750o	35o 56' 15" N
     Lon: W 97.56250o	97o 33' 45" W

      
   • Key things to remember:
     • Latitude is always given before longitude (49^o N 100^o E)
     • Latitudes are parallel, but longitudes are not
     • Degrees West and South are sometimes referred to as negative degrees (−12^o −23^o is the same as 12 S 23 W)
     • A place's latitude effects its climate, but longitude does not
     • Key longitude lines are the Prime Meridian (0^o) and the International Date Line (180^o)
     • Key latitude lines include the equator (0^o), tropic of cancer (23^o 26' N), tropic of capricorn (23^o 26' S), the arctic circle (66^o 33' N), and the antarctic circle (66^o 33' S)

     
      

   • Geographic Coordinate System - Wikipedia
   • Converting Addresses to/from Latitude/Longitude in One Step
   • Search for Latitude and Longitude - U.S. Census Bureau
   • Search for Latitude and Longitude - MapQuest
   • Find Latitude and Longitude - infoplease
    

4. The Hemispheres
    
   • The Equator, the imaginary horizontal line at 0^o degrees latitude at the center of the earth, divides the earth into the Northern and Southern Hemispheres.
      
   • The Prime Meridian, the imaginary vertical line at 0^o degrees longitude, and its twin line of longitude, opposite the Prime Meridian at 180^o longitude, divides the earth into the Eastern and Western Hemispheres.
      
   • With few exceptions, all countries north of the Equator are in the Northern Hemisphere, while all countries south of the Equator are in the Southern Hemisphere. In addition, all countries west of the Prime Meridian are in the Western Hemisphere while those east of the Prime Meridian are in the Eastern Hemisphere.
      
   • The equator passes through these countries.
    

5. The Tropics
    
   • Tropic of Cancer - Located at 23.5 degrees North
      
   • Tropic of Capricorn - Located at 23.5 degrees South
      
   • The area of the planet located between these two lines is known as the "Tropics". This area experiences no dramatic change in season because the sun is consistently high in the sky throughout the year.
      
   • Areas north of the Tropic of Cancer and south of the Tropic of Capricorn experience dramatic seasonal climate changes, because of the earth's tilt, and the subsequent angle of the sun. When it's summer North of the Tropic of Cancer, it's winter South of the Tropic of Capricorn. The reverse is also true.

1. Reading maps is not usually difficult because there are some rules that are generally followed when creating and reading maps:
    
   • North, South, East, and West are the four main "cardinal" directions.
      
   • On a map, North is at the top, South at the bottom, West to the left, and East to the right.
      
   • Every map has a Map Scale which relates distance on the map to the world. For example, one inch equals one mile.
      
   • Using the scale of a map, you can tell the actual distance between two points for real.
      
   • Maps use map symbols to represent real-world things, such as buildings, trails, roads, bridges, and rivers.
      
   • Maps use colors to share more information. Blue often means water, green means forest, and white means bare land.
      
   • A map has a Legend which lists the symbols it uses and what they mean.
      
   • A grid of imaginary lines wrap around and over the earth. These lines are called Latitude and Longitude and can identify the exact location of any point on earth.
    
2. Keeping those things in mind, you can read pretty much any map.

• More map symbols
• Symbols on a weather map
• Manual of Traffic Signs

1. Use compass rose to identify and use cardinal directions.
    
2. Locate places using a grid.
    
3. Apply latitude and longitude (meridians and parallels) to identify direction on maps and globes.
    
4. Measure and estimate distance using a simple scale.
    
   • Many but not all maps are drawn to a scale, expressed as a ratio such as 1:10,000, meaning that 1 of any unit of measurement on the map corresponds to 10,000 of that same unit in reality. This allows the reader to estimate the sizes of, and distances between, depicted objects. A larger scale (i.e. the second number of the ratio is smaller) shows more detail and supports more accurate estimates, thus requiring a larger map to show the same area.
      
   • For modern examples, published maps designed for the hiker (USGS Topographic maps) are often scaled at the ratio of approximately 1:25,000, while maps designed for the motorist to display major highways might be scaled at 1:250,000 or 1:1,000,000. In any case, a properly made map will either state its scale, or declare that it is not scaled and can not be reliably used to deduce distances.
      
   • Here is an example of a Bar Scale found on a map.
     The scale shows that about 1.25 inches equals 5 miles. The smaller increments to the left of zero are each 1 mile and are used to estimate smaller distances. Notice the scale is 1/250000 - that means 1 inch on the map is equal to 250,000 inches on the real land.

     5 miles = (5) (5280 feet) = (5) (5280) (12 inches) = 316,800 inches. 316,800 inches / 250,000 = 1.27 inches)

Look at any map of the United States and notice the kinds of place names (toponyms) that appear. For example on a map of Texas you will see cities or towns named San Angelo and San Antonio, Houston and Austin, New Braunfels and Fredericksburg, Amarillo, Midland, and El Paso, among many. Place names can give clues to past cultural landscapes. They can also offer evidence of past migrations (sequent occupance) in an area, even when time has erased other evidence.
 

• Many toponyms have two parts:
   
  • generic (classifying), such as John's Town, Pitt's Burgh, Nash('s) Ville
     
  • specific (given), such as Battle Creek (Michigan) - this is an event (a battle took place) and a landscape feature (the creek).
   
• There are nine categories of toponyms:  

  Category	Examples
  Descriptive toponyms	Rocky Mountains, Chicago (Stinking Onions in the language of the first inhabitants)
  Associative Toponyms	Mill River (a mill was on the river), Springfield
  Incident Names	Battle Creek, Bloody Ridge, Cut and Shoot
  Possessive Names	Castro Valley, Pittsburgh
  Commemorative (commemorating someone well-known or in honor of a famous person)	Pleasant Valley, Greenland
  Manufactured (made up names)	Tesnus (Sunset spelled backwards), Reklaw (Walker spelled backwards) Iraan (Ira and Ann name the town after each other)
  Mistaken (historic errors in identification or translation)	West Indies (not west of the Indies and not the Indies)
  Shift Names (relocated names or names from settler's homeland)	Athens (Greece and Texas), Palestine (Middle East and Texas), New Mexico (settlers from Mexico named their new home after their previous home), New England.

   

1. A thematic map displays spatial pattern of a theme or series of attributes. In contrast to reference maps which show many geographic features (forests, roads, political boundaries), thematic maps emphasize spatial variation of one or a small number of geographic distributions.
    
2. These distributions may be physical phenomena such as climate or human characteristics such as population density and health issues.
    
3. These types of maps are sometimes referred to as graphic essays that portray spatial variations and interrelationships of geographical distributions. Location, of course, is also important to provide a reference base of where selected phenomena are occurring. While general reference maps show where something is in space, thematic maps tell a story about that place.
    
4. Thematic maps serve three primary purposes:
    
   • They provide specific information about particular locations.
      
   • They provide general information about spatial patterns.
      
   • They can be used to compare patterns on two or more maps.
    
5. Methods of thematic mapping:
    
   • Choropleth map - the most commonly used method of thematic mapping. Choropleth maps are particularly suited for charting phenomena based on predefined areas. Think of it as a multi-colored checkerboard map.
        
   • Proportional symbol map - also known as graduated symbols, these maps represent data associated with point locations (i.e., cities or counties). The data is displayed with proportionally sized symbols to graphically represent a realistic difference in occurrence.
        
   • Isarithmic map - also known as contour maps, depict smooth continuous phenomena such as precipitation. They are also well-suited to displaying three-dimensional values such as elevation i.e; on topographic maps.
        
   • Dot map - a map using dots to show the presence of a feature or occurrence and display a spatial pattern. Dr. Snow used this method in his famous map. One dot represented one death. Note, though, that a dot is not required to represent a single unit and may indicate any number of entities.
        
   • Dasymetric map - hese maps utilize areal symbols. However, although boundaries are displayed on dasymetric maps, these geographic units may span multiple theme values. Plots often represent extremes in the data sets, without much coverage in between. For that reason, and because they can be difficult to generate, dasymetric maps are not very common.
    

1. A political map is a map that shows lines defining countries, states or territories. It is unlike other maps in that its purpose is to show borders. A political map also makes a deliberate political statement about which areas of the earth belong to a country or state.
    
   • Identify and interpret regional patterns.

1. A physical map shows identifiable landmarks such as mountains, rivers, lakes, oceans, and other permanent geographic features.
    
   • Identify and interpret regional patterns.

1. A topographic map is characterized by large-scale detail and quantitative representation of relief, usually using contour lines.

   Contour lines show the elevation changes of the terrain. These are called Topographic Maps because they show the topography of the land. In this example, the elevation at the spot marked A is about 4400 feet above sea level as indicated on the contour line close to it. Point B is not close to a line number. By paying attention to the light and dark lines, you can figure out that it is about 4350 feet.

   
    
   • Identify and interpret regional patterns.