- Earth's crust.
A modern view of the inner structure of the planet
In the middle of the last century on the basis of the lastAt that time, seismological data, scientists came to the conclusion that the deep shells have a more complex device. Then the seismologists found out that the earth's core is divided into internal and external, and the mantle consists of two layers: the upper and lower layers.
Outer shell of the earth
The Earth's crust is not only the highest, mostthin, but also the most well-studied of all layers of the earth's surface. Its thickness (power) reaches a maximum mark under the mountains (about 70 km) and a minimum - under the waters of the world ocean (5-10 km), the average thickness of the earth's crust under the plains ranges from 35 to 40 km. The transition from the earth's crust to the mantle is called the boundary of Mohorovich or Moho.
It should also be noted that the earth's crust, together with the upper part of the mantle, form the stone shell of the Earth - the lithosphere, whose thickness varies from 50 to 200 km.
Next to the lithosphere is the asthenosphere -softened liquid layer with increased viscosity. In addition, it is this component of the earth's surface that is called the source of volcanism, since it contains the centers of magma pouring out into the earth's crust and to the surface.
In science, it is customary to distinguish several types of crust
Mainland or continental spreadswithin the boundaries of the continents and shelves, consists of basaltic, granite-geysovogo and sedimentary layers. The transition of a granitic-geysovy layer to a basaltic layer is called the Conrad boundary.
Submatrix crust is a transitional type located on the periphery of the interior and marginal seas, as well as under island arcs.
The sub-oceanic crust is similar in structure to oceanic crust, especially well developed in the deep-water parts of the seas and at great depths of oceanic troughs.
The middle geosphere
Deep layer of the planet Earth
Earth core is the least explored layerOf the Earth. Reliable information about it is very small, with complete certainty it can only be said that its diameter is about 7 thousand kilometers. It is believed that the composition of the earth's core includes an alloy of nickel and iron. It should also be noted that the outer core of the planet has a large thickness and is in a liquid aggregate state, while the inner core is smaller in thickness and harder in consistency. From the mantle, the terrestrial core is separated by the so-called Gutenberg boundary.