The Earth's crust - upper solid Earth

upper solid Earth is called the crust and part of the lithosphere, which is translated from the Greek literally means "stony" or "hard ball".It includes part of the upper mantle.All of this is directly over the asthenosphere ("impotent ball") - over the more viscous or plastic layer, as if the underlying lithosphere.

internal structure of the Earth

Our planet is in the form of an ellipsoid, or more precisely, the geoid, which is a three-dimensional geometric body closed form.It is essential surveying the concept literally translated as "Earth-like".It looks like our planet looks.Internally it is arranged as follows: - The Earth is composed of layers separated by borders, which have their own specific names (most of them are clear - Moho, or Moho separates the crust and mantle).The core is the center of our planet, the shell (or mantle) and bark - top hard shell of the Earth - are the main layers, two of which - the core and the mantle, in turn, are divided into 2 sub-layer - the inner and outer or upper and lower.Thus, the core radius of the sphere is equal to 3.5 thousand kilometers, consists of a solid inner core (radius 1.3) and external liquid.A gown or silicate shell is divided into upper and lower parts, which together account for 67% of the mass of our planet.

The thinnest layer of the planet

upper solid surface of the Earth is a rather thin outer skin (on land - 40-80 km under water - 10-15).It accounts for only 1% of the mass of the Earth.The Earth's crust is made up of two types - the land is a continental sea floor - ocean.There are transition zones located mostly along the shores of oceans - an island-arc.Geographically, the thickest part of the crust falls on the mountains of the Himalayas in particular (75 km), the center of the ocean - it is the thinnest part (5-7 km).The thickness of the lithosphere is on land and on the ocean floor were respectively 5-100 and 25-200 kilometers.It should be noted that in the lithosphere not included the entire top layer of the mantle, but only a small fraction to a few tens of kilometers, whereas the layer itself reaches from 500 to 900 km.

physical and chemical composition of the Earth

solid Earth is composed of three types of rocks - sedimentary (clastic,
chemical, biogenic), igneous or magmatic (accounting for 95% of the lithosphere: on land dominated by granites at the bottom- basalts) and metamorphic (formed in the Earth's thicker).Under the oceanic water column crust consists of two layers.99.5% of the chemical composition, which has a hard outer shell of the earth, it is necessary to hydrogen and oxygen, aluminum and silicon, iron, magnesium, calcium and sodium - only eight elements of the periodic table.All information about the internal structure of the Earth are theoretical scientific solutions.For direct study is available only the upper solid Earth, because before the next layer of modern man can not physically reach.Therefore, all issues relating to the structure of our planet, disputable.However, on the surface, not all shown, and investigated.It remains controversial even the origin of the earth's crust.Therefore, it is all relevant areas of the study of the lithosphere.It focused the available natural resources, and in the upper part of the soils are so many meaningful in life.

Features lithosphere

Thus, the boundaries of the lithosphere can be identified by the interface, which bears the name of the Serbian geophysicist Moho, and that is determined by the differences of seismic velocities.And these boundaries occur harsh, threatening environmental disaster processes - shifts, including tectonic, landslides and mudslides, erosion.Sami soils arose simultaneously with the life on Earth and are the product of the impact of the environment - water, air and living organisms and plants.Depending on various conditions (geological, geographical and climatic), this important natural resource has a thickness of 15 cm to 3 m. The value of certain types of soils is very high.For example, Ukrainian black earth by the Germans during the occupation rolls exported to Germany.Speaking about the crust, we can not say about the lithospheric plates, is a large solid areas, moving at a liquid layers of the mantle and move relative to each other.Their rapprochement and "raids" threaten tectonic shifts that may be the cause of accidents in the world.