Scientists Say: Latitude and Longitude

One measures the distance from the equator, the other from the Prime Meridian


This illustration of Earth is overlaid with a grid of latitude and longitude. The horizontal lines are latitude and the vertical lines are longitude.

Hellerick/Wikipedia/ (CC BY-SA 3.0)

Latitude  (noun, “LӐ-tih-tood”)

This is how scientists, sailors and others measure how far north or south they are from the equator. Lines of latitude form a series of horizontal stripes around the globe. The equator sits at 0°. The degrees increase as you move north or south from that line. The North Pole sits at 90° N, and the South Pole at 90° S. Any point on the surface of the Earth between 0 and 90° N is a measure of north latitude. If the point is between 0 and 90° S, it’s a measure of south latitude. One degree of latitude is about 111 kilometers (69 miles) in distance.

In a sentence

Winds can drive floating trash from lower latitudes toward the Arctic.

Longitude (noun, “LAWN-gih-tood”)

This is how scientists, geographers and sailors measure the east-west position of a location. Longitude is measured from the Prime Meridian. This is an imaginary line that runs from the North Pole to the South Pole through Greenwich, England. The Prime Meridian marks 0°. Measurements to the east of the Prime Meridian (toward Russia) run from 0° to 180° E. Measurements to the west of the Prime Meridian (toward Canada) measure from 0° to 180° W. (This is why we say that the United States lives in the “Western Hemisphere.”)

Latitude and longitude both start with “L” and end with “-tude,” so they sound similar. How can you remember the difference? Think of a ladder, leaning against Earth, balanced on the equator. The rungs going across are latitude, because lat stays flat! Those rungs link the long(itude) pieces together.

In a sentence

One nautical mile is 1/60th of a degree of longitude when measured at the equator.

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