The thickness of the crust and the state of the interior of the Earth

In any case, at some distance from the surface, at depths that compared with the diameter of our planet is very small, dominated by an extremely high fever. If we assume that geothermal degree = 33 m, then at a depth of 66 km, 9 miles or incomplete, there must exist a temperature of 2000 °; it is enough to melt all the rocks, at least under the conditions that are observed on the ground surface . Should we conclude from this that within the Earth is flaming mass? And if so, at what depth it is? These questions are among the most important but most difficult in the whole of geology. Solution to their science is a long time, but a satisfactory answer and impossible at the present moment. Already Descartes and Leibniz admits the existence of the fiery liquid core inside the Earth, but only the Laplace, Fourier, and Cordier scientifically substantiated this hypothesis. Temperature rise toward the center and the existence of hot springs confirm it, and lava pouring out of volcanoes, directly indicate the existence within the Earth's molten mass. The similarity of the composition of lavas in various parts of the Earth causes the attribute to them a common origin from a single large central mass and makes it impossible for an explanation of volcanic phenomena of local processes. During all periods of Earth's history, to the most recent times, there are strong fluctuations of the continents that point, apparently, to exist beneath a rolling basis. Compression of the Earth at the poles is also proof of the original fiery-liquid state of the Earth: a solid body could never get a form that corresponds to the shape of rotating liquid body. These facts constitute sufficient grounds to admit the existence of the fiery liquid core inside the Earth, and now many people are convinced of the validity of this hypothesis. As for the thickness of the crust, then the opinions are divided: some think that even at a depth of 21 / 2 miles, or at least, at a depth of 5 - 6 miles begins molten mass. Others consider it unlikely that there exists a thin crust and rightly believe that it should extend at least 14 - 20 miles, this figure is now accepted by many and is becoming more and more supporters. However, in the latter case, the difference in the size of a hard shell and a central liquid core would be too large: on the globe with a diameter of 1 m core was not thicker than 23 mm. For a visual representation of these figures is a schematic drawing of 139. The outer circle represents the circumference of the Earth, the thickness at the line - the crust in the 6 Department of Geography. miles, the space between the first and second round - the bark of 55 miles, and finally, the distance between the outer and inner circle corresponds to 250 miles. Currently, supporters of the fiery liquid core is credited with the crust thickness, significantly exceeding 20 miles. From experience we know that due to the pressure melting point rises. Inside Earth there is an extremely high pressure, and hence have to admit that the fiery-liquid mass, in any case is a very considerable depth.