Surface of the earth

from Wikipedia, the free encyclopedia
The surface of the earth (computer animation)

The surface of the earth is the interface between the solid earth's crust (including the soil ) and the bodies of water on the one hand and the atmosphere on the other. It can be divided into hemispheres (hemispheres, from ancient Greek ἥμισυς hemisys "half" and σφαῖρα sphaira "sphere") according to various criteria , i.e. in halves of the earth's surface.

Terrain heights on the Earth's surface to the mean sea level relative. This level surface - the geoid - has approximately the shape of an ellipsoid and a surface of 510 million km², of which around 71% is covered by oceans.

Ways of looking at geosciences

  • The Physical Geography deals with the majority of the earth's surface and its system contexts.
  • The geomorphology (part of geography) explores the exact shape (relief) of the earth's surface and (together with the Geology ) its origin. 37.4% of the earth's land surface is between 1000 and 2000 m above sea level .
  • The Geodesy is concerned with the measurement of the earth's surface and infrastructure located on it, and - together with the geophysics - with the Earth's gravity .
  • The Soil Science examines the uppermost organic embossed layer below the earth's surface.

In large parts of the land areas, especially in plains and hilly landscapes in regions with a humid climate , soil formsthe top layer below the earth's surface. It arises from the weathering of solid rock and from loose rock through the enrichment of these mineral substances with organic matter ( humus ). Depending on the degree of weathering, the chemical and physical properties of the parent rock and the prevailing environmental conditions, different soil types and types are created . In mountainous areas, especially in the high mountains and under extreme climatic conditions, however, the earth's surface often consists of bare rock or loose rock that is hardly or notsubjected toany soil formation processes .

Breakdown by hemispheres

Earth's equator and longitudes
In addition, the northern and southern hemisphere as well as the western and eastern hemisphere designate cultural and economic-political divisions, which are chosen relatively arbitrarily. Its use in this context established itself during the Cold War period in the middle of the 20th century. The southern hemisphere referred to the Third World , the eastern hemisphere to the area of ​​Europe and Asia ( Second World ) influenced by communism or real socialism . Today, due to the changed geopolitical situation, this classification is hardly used in specialist literature.
In the treaties of Tordesillas and Saragossa (1494, 1529), in the course of colonialism, the surface of the earth was divided according to longitude into a Spanish and a Portuguese sphere of influence.
The division into Old World (Eurasia, Africa) and New World (both America) is still common, which is also relatively unspecific.

Breakdown by water and land

Geomorphology divides the earth's surface into areas that are covered by water : lakes , rivers and seas , and areas that are not covered by water: mainland and islands .

While the term "surface" for areas not covered by water is relatively simple to understand as the interface between the lithosphere and / or pedosphere and the atmosphere ( top edge of the terrain ), for water bodies it refers either to the visible water surface ( water level ) or the interface between the lithosphere (including the sediments or " subhydrischen floors ") and water body ( a body of water , engl. sediment-water interface ). On closer examination, however, alternatively, the "visible from the top" surface, including the is also in the land masses vegetation cover and superstructure ( topography ) , or only ground surface ( orography ) meant.

In large-area glaciated regions such as the Arctic and the Antarctic , where parts of the ice sheet extend far into the coastal waters as ice shelves , the question arises whether the surface of the ice body is part of the earth's surface or not.


Total area of
the earth
510,000,000 km² 100%
Water surface 360,570,000 km² 70.7%
Land area 149,430,000 km² 29.3%

Land area

The share of the land area is about 148.9 million  km² (29%); the country is spread over continents and islands:

continent Land area proportion of
Asia (excluding the polar islands) 044.4 million km² 031%
America (excluding polar regions) 038.3 million km² 027%
Africa 029.3 million km² 020%
Antarctica 013.2 million km² 009%
Europe (excluding Iceland , Novaya Zemlya , Atlantic Islands) 009.9 million km² 007%
Australia (with Tasmania ) 007.7 million km² 005%
total 148.9 million km² 100%

In relation to the ice-free areas of the world (i.e. excluding the majority of Greenland and Antarctica), the land area is characterized by natural and man-made large habitats , which at the beginning of the 21st century comprise the following orders of magnitude:

Permanent human
space (residential areas, infrastructure, intensively used areas) 2004
72,084,920 km 2 53%
Agricultural area in 2009 48,827,330 km 2 35.9%
Extensively or seasonally used natural space 2004 42,162,880 km 2 31%
total forest area (used and unused) 2010 40,204,320 km² 29.6%
Unused, “wild” natural spaces 2004 21,761,480 km 2 16%

Water surface

The share of the water surface is approx. 361.2 million km² (71%); the water is mainly distributed in oceans :

ocean % middle deep
Pacific Ocean 47% 3870 m
Atlantic Ocean 24% 3380 m
Indian Ocean 20% 3600 m
Southern ocean 05%
Arctic Ocean 04%

Heights (hypsometry)

The mean height of the mainland areas is around 700 m (Europe 300 m, Asia 880 m, America 610 m, Africa 660 m, Oceania and Australia 300 m). The earth's surface reaches its highest point with Mount Everest at 8,848 meters above sea level. The deepest freely accessible point on the earth's surface is on the shores of the Dead Sea , the water surface of which is 423 meters below sea level. The deepest point of the surface of the continental crust is under the Denman Glacier of the Antarctic Ice Sheet , where it reaches a depth of about 3,500 m below sea level. The mean depth of the seas is about 3,500 m and the deepest point of the surface of the earth's crust or the lithosphere is in the Mariana Trench at about 11,000 meters below sea level.

Other heavenly bodies

Comparison of the surface of the earth with other planets of the solar system and the earth's moon:

Heavenly bodies Surface in km²
Jupiter * 61,420,000,000
Saturn * 42,610,000,000
Uranus * 8,083,000,000
Neptune * 7,620,000,000
earth 510,100,000
Venus 460,200,000
Mars 144,600,000
Mercury 74,760,000
moon 37,960,000

(*) Please note that Jupiter, Saturn, Uranus and Neptune are gas planets without a solid surface. With them, the "surface" is calculated using the zero level , which is by definition the level at which the gas pressure is 1  bar .

Web links

Commons : Hemisphere  - collection of images, videos, and audio files
Wiktionary: Earth's surface  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Conradin Burga, Frank Klötzli and Georg Grabherr (eds.): Mountains of the earth - landscape, climate, flora. Ulmer, Stuttgart 2004, ISBN 3-8001-4165-5 , p. 21.
  2. All details are rough numbers. Source:  ( Page no longer available , search in web archives )@1@ 2Template: Dead Link /
  3. All information roughly; Sources see table
  4. a b c Study Last of the wild, version 2. At: “Socioeconomic Data and Applications Center” of the “Center for International Earth Science Information Network (CIESIN)” at Columbia University, New York. Accessed in September 2012. Percentages of the study applied to ice-free land area in km 2 .
  5. to World Bank - World Bank Data ; converted to ice-free land
  6. to World Bank - World Bank Data ; converted to ice-free land
  7. Mathieu Morlighem, Eric Rignot, Tobias binder and 34 other authors: Deep glacial troughs and ridges stabilizing unveiled beneath the margins of the Antarctic ice sheet . In: Nature Geoscience . December 12, 2019, doi : 10.1038 / s41561-019-0510-8 (English).