Search results
Results from the WOW.Com Content Network
On Earth, the Rayleigh number for convection within Earth's mantle is estimated to be of order 10 7, which indicates vigorous convection. This value corresponds to whole mantle convection (i.e. convection extending from the Earth's surface to the border with the core). On a global scale, surface expression of this convection is the tectonic ...
David A. Bercovici (born in September 1960) is an American geophysicist. He is primarily known for his theoretical explanations of why planet Earth has plate tectonics.He is also known for his development of models of how the Earth's mantle recycles and stores water and how such hydrological processes are involved in Earth's geochemical history.
The pressure at the bottom of the mantle is ≈140 GPa (1.4 Matm). [24] The mantle is composed of silicate rocks richer in iron and magnesium than the overlying crust. [25] Although solid, the mantle's extremely hot silicate material can flow over very long timescales. [26] Convection of the mantle propels the motion of the tectonic plates in the
Donald Lawson Turcotte (born 22 April 1932) is an American geophysicist most noted for his work on the boundary layer theory of mantle convection as part of the theory of plate tectonics. [3] He works at the University of California, Davis .
Earth heat transport occurs by conduction, mantle convection, hydrothermal convection, and volcanic advection. [15] Earth's internal heat flow to the surface is thought to be 80% due to mantle convection, with the remaining heat mostly originating in the Earth's crust, [16] with about 1% due to volcanic activity, earthquakes, and mountain ...
In many real-life applications (e.g. heat losses at solar central receivers or cooling of photovoltaic panels), natural and forced convection occur at the same time (mixed convection). [4] Internal and external flow can also classify convection. Internal flow occurs when a fluid is enclosed by a solid boundary such as when flowing through a pipe.
The catastrophe is defined as when the mean mantle temperature exceeds the mantle solidus so that the entire mantle melts. Using the geochemically preferred Urey ratio of U r = 1 / 3 {\displaystyle Ur=1/3} and the geodynamically preferred cooling exponent of beta = 1 / 3 {\displaystyle {\text{beta}}=1/3} the mantle temperature reaches the ...
Geodynamic mantle convection models have included compositional distinctive material. The material tends to get swept up in ridges or piles. [ 10 ] When including realistic past plate motions into the modeling, the material gets swept up in locations that are remarkably similar to the present day location of the LLSVPs. [ 18 ]