Search results
Results from the WOW.Com Content Network
Here, is the thickness of the oceanic mantle lithosphere, is the thermal diffusivity (approximately 1.0 × 10 −6 m 2 /s or 6.5 × 10 −4 sq ft/min) for silicate rocks, and is the age of the given part of the lithosphere. The age is often equal to L/V, where L is the distance from the spreading centre of mid-ocean ridge, and V is velocity of ...
Cartoon showing the isostatic vertical motions of the lithosphere (grey) in response to a vertical load (in green) In geology, lithospheric flexure (also called regional isostasy) is the process by which the lithosphere (rigid, thin outer layer of the Earth) bends under the action of forces such as the weight of a growing orogeny or changes in ice thickness related to glaciation.
T e is largely dependent on the thermal structure of the lithosphere, [4] its thickness and the coupling of crust with mantle. For the oceanic lithosphere with coupled crust and mantle, T e is usually taken to the base of the mechanical lithosphere (isotherm of 500 - 600 °C). This way it is also age dependent, as gradually thickens moving off ...
For a typical distance that oceanic lithosphere must travel before being subducted, the thickness varies from about 6 km (4 mi) thick at mid-ocean ridges to greater than 100 km (62 mi) at subduction zones. For shorter or longer distances, the subduction zone, and therefore also the mean, thickness becomes smaller or larger, respectively. [14]
Lithosphere underlying ocean crust has a thickness of around 100 km (62 mi), whereas lithosphere underlying continental crust generally has a thickness of 150–200 km (93–124 mi). [5] The lithosphere and overlying crust make up tectonic plates, which move over the asthenosphere. Below the asthenosphere, the mantle is again relatively rigid.
The LAB is particularly difficult to study in these regions, with evidence suggesting that the lithosphere within this old part of the continent is at it thickest and even appears to exhibit large variations in thickness beneath the cratons, [13] thus supporting the theory that lithosphere thickness and LAB depth are age-dependent.
A lunar eclipse above Lofer, Austrian province of Salzburg, in the early hours of Monday, Sept. 28, 2015. (AP Photo/Kerstin Joensson)
However, a thin 5-km-thick lithosphere cannot withstand the large stress of 6 kbar exerted by a 10 km×10 km mountain. [2] [8] To compare, the maximum stress that the lithosphere of the Earth can withstand is 2 kbar. [2] Thus, Io requires a thicker lithosphere to bear the overwhelming stresses imposed by globally distributed mountains. [2]