Maps and Map projections

Some of this information can be found at http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html , http://olc.spsd.sk.ca/DE/k9mod/mapskill/mod3fl5.swf , and wikipedia.

A map is a visual representation of an area.

Types of Maps

There are several types of maps. Each show different information. Most maps include a compass rose, which indicates which way is north, south, east and west. They also include a scale so you can estimate distances. Here’s a look at some different types of maps.

Climate maps
give general information about the climate and precipitation (rain and snow) of a region. Cartographers, or mapmakers, use colors to show different climate or precipitation zones.
Economic or resource maps
feature the type of natural resources or economic activity that dominates an area. Cartographers use symbols to show the locations of natural resources or economic activities. For example, oranges on a map of Florida tell you that oranges are grown there.
Physical maps
illustrate the physical features of an area, such as the mountains, rivers and lakes. The water is usually shown in blue. Colors are used to show relief–differences in land elevations. Green is typically used at lower elevations, and orange or brown indicate higher elevations.
Political maps
do not show physical features. Instead, they indicate state and national boundaries and capital and major cities. A capital city is usually marked with a star within a circle.
Road maps
show major–some minor highways–and roads, airports, railroad tracks, cities and other points of interest in an area. People use road maps to plan trips and for driving directions.
Topographic maps
include contour lines to show the shape and elevation of an area. Lines that are close together indicate steep terrain, and lines that are far apart indicate flat terrain.

    

Maps of the world or large areas are often either ” or ‘physical’ (Click political for a sample political map). The most important purpose of the political map is to show territorial borders; the purpose of the physical is to show features of geography such as mountains, soil type or land use including infrastruction such as roads, railroads and buildings. Topographic maps show elevations and relief with contour lines or shading.

Maps that depict the surface of the Earth also use a projection, a way of translating the three-dimensional real surface to a two-dimensional picture. Perhaps the best-known world-map projection is the Mercator projection.

A map projection is used to portray all or part of the round Earth on a flat surface. This cannot be done without some distortion.Every projection has its own set of advantages and disadvantages. There is no “best” projection. The mapmaker must select the one best suited to the needs, reducing distortion of the most important features.

A mercator map is a map projection that uses straight constant lines.

We divide the earth’s surface into two equal parts called hemispheres.  The equal parts are called Northern Hemisphere and the Southern Hemisphere

There is an imaginary line that divides the Northern Hemisphere and the Southern Hemisphere. That line is called the Equator The vertical lines that divide the Earth into equal parts and run through the North and South poles are called Meridians. Unlike the equator, there are many meridians.  Any lines that runs through both poles is called a meridian. The line dividing the world into east and west is called the Prime Meridian.  Prime means of most importance. The lines on a map that run left to right are called lines of Latitude.  The equator is the line of latitude in the center of the map.The lines on a map that run top to bottom are called lines of Longitude. Lines of longitude are called meridians.

The basic unit of measurement on a map is called a degree. Starting at a point and following it all the way around will give you a total of 360 degrees! If the entire distance around is 360 degrees.  What would half be?

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