Degrees of longitude are divided into 60 minutes. Each minute of longitude can be further divided into 60 seconds. A degree of longitude is about kilometers 69 miles at its widest. The widest areas of longitude are near the Equator , where the Earth bulges out. Because of the Earth's curvature , the actual distance of a degrees, minutes, and seconds of longitude depends on its distance from the Equator.
The greater the distance, the shorter the length between meridians. All meridians meet at the North and South Poles. Longitude is related to latitude , the measurement of distance north or south of the Equator. Lines of latitude are called parallel s. Maps are often marked with parallels and meridians, creating a grid. The point in the grid where parallels and meridians intersect is called a coordinate. Coordinates can be used to locate any point on Earth. Knowing the exact coordinates of a site degrees, minutes, and seconds of longitude and latitude is valuable for military , engineering , and rescue operation s.
Coordinates can give military leaders the location of weapons or enemy troops. Coordinates help engineers plan the best spot for a building, bridge, well, or other structure. Coordinates help airplane pilots land planes or drop aid packages in specific locations. Into the Great Wide Open It was not until the 18th century that people were able to correctly determine their longitude, even though they had been able to figure out latitude for some time.
Not being able to reckon longitude was dangerous for sailors. Without an exact location, they could easily run out of food or water on a long expedition into uncharted territory. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
The Rights Holder for media is the person or group credited. Jeannie Evers, Emdash Editing. Caryl-Sue, National Geographic Society. Unlike latitude , which has the equator as a natural starting position, there is no natural starting position for longitude.
Other meridians have been used in the past, but most scientists now agree to use the Prime Meridian. For centuries navigators at sea were seldom able to know their longitude. The problem was solved by making better clocks chronometers in the early 19th century. Longitude, as opposed to latitude does not maintain a constant distance between degrees since meridians all come together at the poles and are far apart at the equator.
The "long" sense of the root may be easier to see in some uses of the adjective longitudinal : A longitudinal study is a research study that follows its subjects over many long years, and a longitudinal engine is one that drives a crankshaft that runs lengthwise under a vehicle as in rear-wheel-drive cars rather than crosswise. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'longitude.
Send us feedback. Middle English, from Latin longitudin-, longitudo , from longus. See more words from the same century. Long Island Sound. Accessed 12 Nov. More Definitions for longitude. See the full definition for longitude in the English Language Learners Dictionary. Nglish: Translation of longitude for Spanish Speakers.
Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! Log in Sign Up. Save Word. Definition of longitude.
0コメント