Overburden pressure

As lithostatic pressure (. Alt-/neugriechisch by: λίθος lithos [. M] -, stone ',' rock '; symbol: rsp) at a certain depth is the part of geophysics, geology and geotechnics called that pressure that the above located rock layers exert their weight. This specific pressure is an isotropic stress field.

Definition

The formula is:

The correct spelling is:

During the hydrostatic pressure with increasing water depth every 10 m to 1 bar increases, the increase is in layers of rock about 3-fold. The exact ratios depend mainly on the rock density, which is in the earth's crust from 2 to 3.3 g / cm ³ ( sediments about 2 g / cm ³, Granite and limestone and gabbro 2.7 3.3 ).

In the upper mantle rocks are again compact (eg: olivine from 3.3 to 4 g / cc, under very high pressure even 5 g / cc). Therefore, one of the exact calculation of internal pressures of the most difficult tasks for Seismology and Applied Geophysics. At the transition between the upper and lower mantle - in about 700 km depth - the pressure is about 25 GPa, which corresponds to 250,000 times atmospheric pressure.