How To Use A Map

This is an article about how to use a map. It talks about the different things that a map can help you to do.

A map is a type of picture of an area as it may be seen from above. It will have symbols and other information to help make it easier to understand. A map can show the street that you live on or it can show the world. Maps will help people find their way from one place to another. It will also record all types of information about people, places, and things.

Because the planet is round, a round globe will give the most accurate picture of the shapes and sizes of land and water areas on the earth. Flat maps are cheaper and easier to use. They are designed to show smaller areas in grater detail than a globe. Because of this, flat maps are used more than globes.

To be able to use maps, you must know how to read them. The language of a map is really quite simple. A good map will include instructions to help you understand them. Once you have become familiar with the language of maps, you will be able to use them to find out many things.

One of the most basic uses of maps is to help you find specific places. All location is relative. You need a starting pint. Everything else will be described as being a certain distance and direction from that point. The earth has two natural starting points. These are the North and the South poles. The ancient Greeks invented a geographic grid, this grid is still in use today. The grid is made up of two sets of imaginary lines. They cross each other at regular intervals. One set of lines is a series of circles running east and west around the earth. The other set goes north and south. The east and west lines are called parallels of latitude and the north and south lines are known as meridians of longitude. These circles are all shown in degrees.

Why do map markers need two sets of lines? Giving a location only in latitude would be like telling people that you live on South Street, without telling them where on South Street. There are other kinds of map grids that can help you to locate places. Many maps will have a series of letters beginning with "A" running across the top and bottom of the map. The is also a series of numbers beginning with "1" running along the right and left margins. To find a place that is located at B-6 on the map index, you must look in the box formed where B and 6 cross each other.

Another thing maps will tell us is direction. On most maps north is at the top of the map. North and up are not, however, the same. "Up" is away from the surface of the earth. "North" is toward the North Pole. If you are facing north, east will be to your right, west will be to your left, and south will be behind you.

It will be easy for you to find north on the globe, all you will need to do is look for the North Pole. On a flat map an arrow or compass rose will tell you which way north is.

Maps can do so much more than tell us where and which way. They can tell us how far. Because the areas that are being mapped are usually hundreds of times larger than the map itself, cartographers had to find a way to describe the relationship between the map and the area that is being mapped. To do this, they let a small length on the map represent a large one on the ground. This relationship is called a scale.

Expressions of the scale can be written in many ways. The most common expression of scale on road maps is the graphic or bar scale. This is a line that is subdivided to show the distance on the area being mapped. To find the distance between two cities on a map with a graphic scale, mark the distance between the tow on a piece of paper or a ruler. Place the paper or the ruler along the graphic scale and read the distance. If you want to measure distance along waterways or other curved places you should use a piece of string.

A verbal scale will give the relationship between the map and the ground in simple English. It might read something like this, "1 inch equals 160 miles."

Another scale that is often used on flat maps is called representative fraction or ration. This gives the relationship between a unit of measurement on the map and the same unit of measurement that is being mapped. This means that 1/10,000 meant that 1 centimeter, inch, or other unit on the map represents 10,000 centimeters, inches, or other units on the area that is being mapped. With an RF scale it will not matter what system of measure is being used. The larger the second number in the RF, the smaller the scale will be. The smaller the second number, the larger the scale will be. You can convert a graphic or a verbal into and RF by multiplying the number of miles per inches by 63,360.

Distances over large areas are measured by great circles rather than straight lines. A great circle divides the globe into two equal halves. The equator is a great circle. It divides the earth into the Northern and Southern Hemisphere's. Any meridian when joined with its opposite is also called a great circle.

Meridians of longitude can be used to tell time anywhere in the world. The earth rotates from west to east at a rate of 15 degrees per hour. This is 360 degrees in a twenty-four hour period. This time 15 degrees west of a point is one hour earlier. 15 degrees east would then be one hour later.

Physical maps show natural features such as mountains, rivers, oceans, and islands. Cultural maps will include people made features such as political boundaries, highways, towns, dams, and oil wells. Cartographers will often use symbols to stand for different features on a map. The symbol will often times look like what they represent. They may use and outline of an airplane to show you where the airport is located. Colors, lettering, and lines are also some of the symbols that will be used. You will find that blue will almost always be used to represent water.

Symbols and other information to help you understand the map are usually placed in a box called the map key. Since not all map symbols are the same, it is important to check the key on each map that you use.

© High Speed Ventures 2011