How to Find Locations Using Lat & Long
Long ago, geographers and mapmakers created a grid system of latitude and longitude to aid in the location of physical features as well as the different nations and cities of the world. This system is still in use today, evident by the fact that nearly every spot on the globe can be calculated in measurements of degrees.
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Instructions
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Latitiude
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Find the equator on the globe. This is the key to understanding latitude, because the equator is the halfway mark for latitude. The equator has a value of 0 degrees.
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Locate the North and South Poles on the globe. These two points have a reading of 90 degrees N (North Pole) and 90 degrees S (South Pole). All points on the globe fall between these parameters. Each place is first measured in degrees, then in decimal points to indicate portions of one degree. So every point on the globe reads between 0 and 90 degrees, with the letter N or S placed afterward to indicate whether it is in the northern or southern hemisphere.
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Search for other lines on the globe that run parallel to the equator. The Arctic Circle and Tropic of Cancer are two well-known lines. These lines that circumnavigate the globe are called parallels. The 49th parallel is famous because it is the dividing line that was established between North and South Korea after the Korean War was over.
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Find on a topographic map the parallel lines of latitude. On a square map, they run parallel to the bottom and top. Each line has a measurement in degrees and minutes, which might look like this: 40 degrees N (north) 32' (minutes). Minutes are used to divide each degree into 60 equal units. However, if one degree of latitude covers approximately 70 miles, then each minute of latitude would be equal to 1.2 miles, a scale that is easily displayed on a topographic map. This new measurement makes it possible to measure the latitude in more precise terms.
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Note that each minute of latitude can be further subdivided into seconds. The notation for this is: ". So if you come across a location that looks like this: 40 N 37' 28", the last number (28) refers to the seconds, which are relatively small divisions on a map. This notation is not very common, but a map reader might encounter it every now and then.
Longitude
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Look on the globe for the vertical lines that run in a north-south direction. These are called longitude lines, and there is no middle--just a beginning and an end. All of these lines add up to 180 degrees. The starting point, or 0 point, occurs at Greenwich, England, and is called the Prime Meridian. Another line is located directly on the other side of the world at the 180 degrees mark. This is called the International dateline. All points in between receive a numerical value between 0 and 180 with an E or a W next to the number, which determines which half of the globe they fall in.
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Search the globe for more vertical lines, or meridians, as they are called. Notice how they are farthest apart at the equator and relatively close together at the two poles. Also, check the progression of the meridians and how the numbers increase as you go east to west.
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Look at a topographic map and see if you can find any vertical lines. Observe how the intersection of the meridians and parallels form square boxes instead of being elongated like they are on a globe. This occurs because most maps only cover a small area, and the variation is so small that the difference is minimal.
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Examine a topographic map for a notation at the bottom, which refers to the degrees and minutes for each vertical line. Longitude is divided into minutes, just like latitude, so a second number indicates minutes. The notation for minutes is the same as it is in latitude. For example, 117 degrees E 22' refers to a subdivision of the 117th meridian that reads as 22 minutes.
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10
Take note that each minute of longitude can be further subdivided into seconds, just as with latitude. If you come across a location that looks like this: 140 W 37' 28", go to the 140th meridian west of the Prime Meridian, and just past halfway to the 141st meridian west should be your location.
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Tips & Warnings
Do not get true north confused with magnetic north. Meridians run in a true north-south direction.
