Question

The variation on the surface of the earth is known as

Answer 1

Answer:

tal surface area of Earth is about 510 million km2 (197 million sq mi).[12] Of this, 70.8%,[12] or 361.13 million km2 (139.43 million sq mi), is below sea level and covered by ocean water.[121] Below the ocean's surface are much of the continental shelf, mountains, volcanoes,[89] oceanic trenches, submarine canyons, oceanic plateaus, abyssal plains, and a globe-spanning mid-ocean ridge system. The remaining 29.2%, or 148.94 million km2 (57.51 million sq mi), not covered by water has terrain that varies greatly from place to place and consists of mountains, deserts, plains, plateaus, and other landforms. Tectonics and erosion, volcanic eruptions, flooding, weathering, glaciation, the growth of coral reefs, and meteorite impacts are among the processes that constantly reshape Earth's surface over geological time.[122][123]

The continental crust consists of lower density material such as the igneous rocks granite and andesite. Less common is basalt, a denser volcanic rock that is the primary constituent of the ocean floors.[124] Sedimentary rock is formed from the accumulation of sediment that becomes buried and compacted together. Nearly 75% of the continental surfaces are covered by sedimentary rocks, although they form about 5% of the crust.[125] The third form of rock material found on Earth is metamorphic rock, which is created from the transformation of pre-existing rock types through high pressures, high temperatures, or both. The most abundant silicate minerals on Earth's surface include quartz, feldspars, amphibole, mica, pyroxene and olivine.[126] Common carbonate minerals include calcite (found in limestone) and dolomite.[127]

The elevation of the land surface varies from the low point of −418 m (−1,371 ft) at the Dead Sea, to a maximum altitude of 8,848 m (29,029 ft) at the top of Mount Everest. The mean height of land above sea level is about 797 m (2,615 ft).[128]

The pedosphere is the outermost layer of Earth's continental surface and is composed of soil and subject to soil formation processes. The total arable land is 10.9% of the land surface, with 1.3% being permanent cropland.[129][130] Close to 40% of Earth's land surface is used for agriculture, or an estimated 16.7 million km2 (6.4 million sq mi) of cropland and 33.5 million km2 (12.9 million sq mi) of pastureland.[131]

Explanation:

Answer 2

The variation on the surface of the earth is known as weathering process.

Explanation:

• The variation on the surface of earth is known as weathering process.

• Weathering process is caused  due to natural calamities like tsunamis ,earthquakes, etc .
• Variation takes place between cells, individual organisms, or groups of organisms of any species and this may be caused either by genetic differences
• Genetic variation is also called genotypic variation.
• Variation caused by the effect of environmental factors on the expression of the genetic potentials is called phenotypic variation.
• Variation can be of two types if the difference of characteristics among individual is considered.
• They are of two types  a) Somatic variation. b)Germinal variation.

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