Understand the purpose and uses of globes and map projections.
Describe the parts of a map and the different types of maps geographers use.
Demonstrate how to read graphs, charts, and diagrams.
Globes and Maps
A globe is the most accurate map projection; however, it is hard to carry a globe around in your pocket. Maps help to project the earth in an easier to manage form, but since the earth is considered a sphere a flat map always distorts the surface of the earth it is showing. If you take the whole peel from an orange and try to flatten it on a table you would have to cut parts of it to stretch it. Mapmaker’s face a similar problem showing the round earth on a flat map. The different ways they have found to do this are called projections. There are several map projections.
Goode’s Interrupted Projection: equal-area projection. Quite accurately presents the size and shape of the continents. Used to compare continent statistics according to area.
Mercator Projection: created by Gerardus Mercator in 1569. Shows land shapes fairly accurately, but not distance or size. Areas distant from the equator are distorted. The Mercator projection does show true directions, making it very useful for sea travel.
Robinson Projection: shows both size and shape of oceans and continents quite accurately. Most distorted near the poles. Textbook and atlas maps are often Robinson projections.
Latitude and Longitude
Since a globe is the most accurate way to represent the earth, geographers set up a system of imaginary lines that crisscross the globe. One line, the Equator, circles the middle of the earth like a belt. It divides the earth into “half spheres” or hemispheres. Everything north of the Equator is the Northern Hemisphere and everything south is the Southern Hemisphere. Another imaginary line running from north to south divides the earth into half spheres in the other direction. This line is called the Prime Meridian, located at 0 degrees longitude. Everything east of the Prime Meridian is in the Eastern Hemisphere and everything to the west is in the Western Hemisphere. North America is in the Northern and Western Hemispheres.
The equator and Prime Meridian are the starting points for two sets of lines used to find any location. Parallels circle the earth and show latitude, which is distance measured in degrees north and south of the Equator at 0° degrees latitude. The letter N or S follows the degree symbol and tells you if the location is north or south of the equator. The North Pole is at 90° degrees North latitude, and the South Pole is at 90° degrees South latitude. The Tropic of Cancer is at 23 1/2°N latitude and the Tropic of Capricorn at 23 1/2°S latitude. The Arctic Circle is at 66 1/2°N latitude and the Antarctic Circle at 66 1/2°S latitude. Meridians run north and south from pole to pole. These lines signify longitude which is distance measured in degrees east or west of the Prime Meridian at 0° degrees longitude. The letter E or W follows the degree symbol and tells if the location is east or west of the Prime Meridian. On the opposite side of the earth is the International Date Line, or the 180° meridian. Lines of latitude and longitude cross each other in the form of a grid system. Knowing a place’s latitude and longitude allows you to locate it exactly on a map (absolute location).
Great Circle Routes
A great circle is the shortest distance between two points on earth. A great circle is any circle you can draw on the earth that divides it into two equal parts. A line drawn along the Equator around the entire earth is an example of a great circle. Traveling along a great circle is called following a great circle route. Airplane pilots and ship captains often use great circle routes to shorten their trips and cut down on fuel needed. The great circle route between two points may not appear to be the shortest distance on a flat map.
Parts of a Map
The map key unlocks the information presented on a map. It explains the symbols used on a map. A compass rose is the direction marker on a map. The compass rose generally includes the cardinal directions: north, south, east, and west. It can also include intermediate directions that fall between cardinal directions. The measuring line on a map is the scale bar. The scale tells you the distance on the earth represented by the measurement on the scale bar. For example, one inch on a map may represent 100 miles on earth. There are many different kinds of maps. Maps that show a wide range of general information are called general purpose maps. Political maps generally show political or human-made divisions of countries or regions. Physical maps show the physical features of and are, like mountains and rivers. Physical maps use colors and shadings to show relief (how flat or rugged the land surface is). Colors may also be used to show elevation. Contour maps show elevation. A contour map has contour lines, one for each major level of elevation. If contour lines are close together, the surface is steep. If the lines are far apart, the land is flat or rises gradually. Another way to show relief is to look at the landscape from the side, or profile. The elevation profile is a cutaway diagram that show level land, hills, and steeper mountains. Special purpose maps include land use and resource maps, geological maps, population density maps, and climate region maps.
Graphs and Charts
Graphs are important in geography (GEOGRAPHY USES MATH!!!). Graphs summarize and give information visually and give useful information. To use a graph you first read the title to see what is the graph’s subject. Then read the labels along the graph’s axes (the vertical and horizontal lines along the bottom and sides of the graph). One axis tells what is being measured and the other tells what units of measurement are being used. Kinds of graphs include bar graphs (used to compare quantities), line graphs (good for showing change over time), circle graphs (or pie graph – used to show how the whole of something is divided), pictographs (uses pictures or symbols to compare something), and climographs (climate graph – combines a line graph and a bar graph and gives an overall picture of the climate – long-term weather patterns). Diagrams are also used in geography. Diagrams are drawings that show steps in a process, or explain how something works. A flow chart is a diagram that combines elements of a diagram and a chart. Charts and tables present organized facts and statistics so they are easier to read.
Practice and Review
Matching, flashcards, concentration, word search
Rags to Riches (A)
Rags to Riches (B)
Rags to Riches (C)
Special Lines of Latitude & Longitude + 5 Themes of Geography
Hangman (No Hints)