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# Latitude and Longitude

Latitude and longitude are imaginary lines that help us label every place on the surface of the earth. The most important line of latitude is the equator, which runs horizontally around the fattest part of the earth. The most important longitude line is the Prime Meridian which runs vertically and goes through Greenwich, England. Another important longitude line is the international date line, which goes vertically through the middle of the ocean opposite the Prime Meridian (it is like the other half of the Prime Meridian).

In the figure above the longitude lines are red and blue. Longitude lines look like someone took the globe and cut it into slices like an orange. They are half circles which intersect at the north and south poles.

Latitude lines look like circles wrapped around the globe that get smaller and smaller as you go farther from the equator. Latitude lines are parallel and never touch each other.

Latitude and longitude are measured in degrees and also have a direction. Latitude goes from 0 degrees (the equator) to 90 degrees (the north or south pole) and is either north or south of the equator. Longitude goes from 0 degrees (the Prime Meridian) to 180 degrees (the international date line) and is east or west of the Prime Meridian. To precisely locate a place, l using latitude and longitude, minutes and seconds are used as well as degrees. Each degree has 60 minutes, and each minute has 60 seconds.

So when you see latitude and longitude coordinates, they look something like this: 47o 36' 25" N, 122o 19' 12" W

The N tells us to look north of the equator. The 47o 36' 25" before the N shows us how far north of the equator we want to be; in this case 47 degrees, 36 minutes, and 25 seconds. Now that we've figured out what latitude we are on, we look at the second part which is the longitude. Since there is a W, we go to the west of the Prime Meridian. The numbers before the W tell us how far west to go, 122 degrees, 19 minutes, and 12 seconds. Now we can find the place this latitude and longitude represents by seeing where the latitude and longitude lines we just found intersect. Using a map, can you find the city that has this latitude and longitude?