World map

A world map is a map of most or all of the surface of Earth. World maps, because of their scale, must deal with the problem of projection. Maps rendered in two dimensions by necessity distort the display of the three-dimensional surface of the Earth. While this is true of any map, these distortions reach extremes in a world map. Many techniques have been developed to present world maps that address diverse technical and aesthetic goals.[2]

This article is about maps of Earth. For other uses, see World map (disambiguation).

A world map on the Winkel tripel projection,
a low-error map projection[1] adopted by the National Geographic Society for reference maps
NASA's Blue Marble Next Generation, a composite of cloud-free satellite images.

Charting a world map requires global knowledge of the Earth, its oceans, and its continents. From prehistory through the Middle ages, creating an accurate world map would have been impossible because less than half of Earth's coastlines and only a small fraction of its continental interiors were known to any culture. With exploration that began during the European Renaissance, knowledge of the Earth's surface accumulated rapidly, such that most of the world's coastlines had been mapped, at least roughly, by the mid-1700s and the continental interiors by the twentieth century.

Maps of the world generally focus either on political features or on physical features. Political maps emphasize territorial boundaries and human settlement. Physical maps show geographical features such as mountains, soil type, or land use. Geological maps show not only the surface, but characteristics of the underlying rock, fault lines, and subsurface structures. Choropleth maps use color hue and intensity to contrast differences between regions, such as demographic or economic statistics.

Map projections
Further information: Map projection
See also: List of map projections

All world maps are based on one of several map projections, or methods of representing a globe on a plane. All projections distort geographic features, distances, and directions in some way. The various map projections that have been developed provide different ways of balancing accuracy and the unavoidable distortion inherent in making world maps.

Perhaps the best-known projection is the Mercator Projection, originally designed as a nautical chart.

Thematic maps
Further information: Thematic map

A thematic map shows geographical information about one or a few focused subjects. These maps "can portray physical, social, political, cultural, economic, sociological, agricultural, or any other aspects of a city, state, region, nation, or continent".[3]

  • Clickable world map(with climate classification)
    Clickable world map
    (with climate classification)
  • A simple political map of the world
    A simple political map of the world
  • A simple physical map of the world
    A simple physical map of the world
  • Topographical map of the world
    Topographical map of the world
  • Map of anthropogenic CO2 emission by country
    Map of anthropogenic CO2 emission by country
  • United Nations Human Development Index by country as of 2016
    United Nations Human Development Index by country as of 2016
  • World map showing life expectancy
    World map showing life expectancy
  • 2018 population density(people per km2) by country
    2018 population density
    (people per km2) by country
  • Volcano map
    Volcano map
  • World map showing the continents circa 200 million years ago (Triassic period)
    World map showing the continents circa 200 million years ago (Triassic period)
  • Satellite image of Earth at night
    Satellite image of Earth at night

Historical maps
Further information: Early world maps

Early world maps cover depictions of the world from the Iron Age to the Age of Discovery and the emergence of modern geography during the early modern period. Old maps provide information about places that were known in past times, as well as the philosophical and cultural basis of the map, which were often much different from modern cartography. Maps are one means by which scientists distribute their ideas and pass them on to future generations.[4]

See also

References
  1. Large-Scale Distortions in Map Projections, 2007, David M. Goldberg & J. Richard Gott III, 2007, V42 N4.
  2. American Cartographic Association's Committee on Map Projections (1988). Choosing a World Map. Falls Church: American Congress on Surveying and Mapping. pp. 1–2.
  3. Thematic Maps Map Collection & Cartographic Information Services Unit. University Library, University of Washington. Accessed 27 December 2009.
  4. "History of maps and cartography". emporia.edu.

Further reading
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