Introduction to Geography
ropic of Cancer 3½ N Arctic Circle 90 N Prime Meridian 0 Arctic Ocean Mississippi R. Appalachian Mts. Europe Rocky Mountains N. America Atlantic Gulf of Ocean Mexico Caribbean Sea Africa Asia W N NW SW S NE E SE Equator 0 Pacific Ocean Tropic of Capricorn 23½ S Amazon R. S. America Indian Ocean Australia Antarctic Circle 90 S Antarctica
Cardinal Directions What is geography? Geography comes from the Greek word Geographia. Geo means earth and graphia means to describe or chart. Geographers study the earth in relation to space and the interactions that take place there. The cardinal directions are North, South, East and West. They can also include up (outward), which is away from the Earth s core, and down (inward), which is toward the Earth s core. The Earth is divided in half. There are to four sections, or hemispheres: the northern hemisphere, the southern hemisphere, the eastern hemisphere, and the western hemisphere.
Latitude and Longitude Imaginary lines that help to identify locations of places used in a grid system. A grid system is used to find latitude and longitude on a map. Latitude lines are parallel to each other and run horizontally (the fatness of the earth). They divide the earth into northern and southern hemispheres and measure distances north or south from the Equator, to 90 0 N and 90 0 S. They are equally spaced, 70 (exactly 69.2) miles in distance from one another. The Equator is 0 0 latitude. Longitude lines run vertically along the earth. They divide the earth into eastern and western hemispheres and run from pole to pole. They measure distances east and west of the Prime Meridian. They range from approximately 70 (exactly 69.2) miles apart at the Equator to 0 miles at the poles. The Prime Meridian runs through Greenwich, England and is 0 0 longitude. Both coordinates are measured in degrees and minutes and seconds, Each degree is divided into 60 minutes ( ) and each minute is divided into 60 seconds ( ). For example Salt Lake City is 40 0 46 N 111 0 53 W, which reads 40 degrees, 46 minutes north (of the Equator) and 111 degrees, 53 minutes west (of the Prime Meridian). The opposite of the Prime Meridian is the Antimeridian. It is on the opposite side of the world from the Prime Meridian. It is located at 180 0 longitude.
Notice how the latitude degrees get larger as they go farther away from the Equator, and the longitude lines get larger as they get away from the Prime Meridian
The Geographer s Tools Maps and Globes A map s function is to show locations of places, landforms and bodies of water, and where they are in relation to other parts of earth. A globe is a 3-dimensional representation of the earth. For most tasks, they are not practical because they re not portable. Maps are two-dimensional graphic representations of selected parts of the earth s surface. They are portable and can be drawn to any scale needed. A disadvantage of maps is that distortion occurs as the earth s surface is flattened to create the map. There are important parts of maps. One is the legend, which tells what various symbols stand for on maps. The other is the scale, which tells size and distance on maps. Cartographers are map makers. They use different types of map projections to reduce types of distortion. A map projection is a way of drawing the earth s surface that reduces distortion caused by resenting a round earth on flat paper.
We ll be studying five types of maps: cylindrical, conic, homolosine, Robinson and relief. Cylindrical map Projections: is a type of map in which a cylinder is wrapped around a sphere (the globe), and the details of the globe are projected onto the cylindrical surface. Then, the cylinder is unwrapped into a flat surface, yielding a rectangular-shaped map. Cylindrical maps have a lot of distortion in the polar regions (that is, the size of the polar regions is greatly exaggerated on these maps). Notice that the lines of latitude and longitude are equally spaced. This is best for using the grid system. A disadvantage of these maps is that it distorts size and shape, especially at the poles.
Conic Map Projections: a type of map in which a cone is wrapped around a sphere (the globe), and the details of the globe are projected onto the cylindrical surface. Then, the cylinder is unwrapped into a flat surface. These maps are best for seeing the poles and the great circle route, which is the distance between any two places on the planet. A disadvantage of this map is that it distorts the size and shapes at the edges of a map.
Homolosine Projections: A map projection with interruptions in the oceans, designed so that the continents appear with their proper size with respect to each other. Some disadvantages of these maps are that the distance is distorted and the oceans are split.
Robinson Projections: a widely-used type of map in which the Earth is shown within an ellipse with a flat top and bottom. These maps show the best combination of size, shape and distance. Some disadvantages of these maps are that they still distort the poles and that the grid system becomes tricky near the edges.
Relief Projection Maps are used to show elevation. The best way to show elevation is by using color.