Search results
Results from the WOW.Com Content Network
The most abundant silicate minerals on the Earth's surface include quartz, the feldspars, amphibole, mica, pyroxene, and olivine. [25] Common carbonate minerals include calcite (found in limestone), aragonite, and dolomite. [26] Elevation histogram of the surface of the Earth—approximately 71% of the Earth's surface is covered with water.
In 2019, 39 million km 2 (15 million sq mi) of Earth's land surface consisted of forest and woodlands, 12 million km 2 (4.6 million sq mi) was shrub and grassland, 40 million km 2 (15 million sq mi) were used for animal feed production and grazing, and 11 million km 2 (4.2 million sq mi) were cultivated as croplands. [272]
The Earth's radius is the distance from Earth's center to its surface, about 6,371 km (3,959 mi). While "radius" normally is a characteristic of perfect spheres, the Earth deviates from spherical by only a third of a percent, sufficiently close to treat it as a sphere in many contexts and justifying the term "the radius of the Earth".
This corresponds to an average flux of 0.087 W/m 2 and represents only 0.027% of Earth's total energy budget at the surface, being dwarfed by the 173 000 TW of incoming solar radiation. [13] Human production of energy is even lower at an average 18 TW, corresponding to an estimated 160,000 TW-hr, for all of year 2019. [14]
Digital Land Surface Models should not be confused with Digital Surface Models, which can be surfaces of the canopy, buildings and similar objects. For example, in the case of surface models produces using the lidar technology, one can have several surfaces – starting from the top of the canopy to the actual solid earth.
1913 saw the beginning of the International Map of the World initiative, which set out to map all of Earth's significant land areas at a scale of 1:1 million, on about one thousand sheets, each covering four degrees latitude by six or more degrees longitude. Excluding borders, each sheet was 44 cm high and (depending on latitude) up to 66 cm wide.
Landforms do not include several man-made features, such as canals, ports and many harbors; and geographic features, such as deserts, forests, and grasslands. Many of the terms are not restricted to refer to features of the planet Earth, and can be used to describe surface features of other planets and similar objects in the Universe.
Planetary surfaces and surface life are of particular interest to humans as it is the primary habitat of the species, which has evolved to move over land and breathe air. Human space exploration and space colonization therefore focuses heavily on them. Humans have only directly explored the surface of Earth and the Moon.