Why doesn't the earth's lithosphere flow?

Answer 1

The rocks below the lithosphere are at least semi-molten. Over long periods of time they circulate in convection cells. As in any convection cell, hotter material is less dense, therefore wells up; colder material is more dense, and therefore sinks.

The seafloor crust is (roughly speaking) part of these convection cells. It is the coldest part of them, and therefore "wants" to sink, which it does in subduction zones. Continental crust is, again roughly speaking, made up of less-dense materials which would be difficult to drag down along with the oceanic crust. You might therefore think of continental crust as the lightweight froth that floats on top of a seething pot of gummy, semi-molten mantle stuff. It might not sink down into what's beneath it, but when everything else moves across the surface of the Earth the continents are definitely along for the ride. These are called convection currents.

Answer 2

The rocks below the lithosphere are at least semi-molten. Over long periods of time they circulate in convection cells. As in any convection cell, hotter material is less dense, therefore wells up; colder material is more dense, and therefore sinks.

The seafloor crust is (roughly speaking) part of these convection cells. It is the coldest part of them, and therefore "wants" to sink, which it does in subduction zones. Continental crust is, again roughly speaking, made up of less-dense materials which would be difficult to drag down along with the oceanic crust. You might therefore think of continental crust as the lightweight froth that floats on top of a seething pot of gummy, semi-molten mantle stuff. It might not sink down into what's beneath it, but when everything else moves across the surface of the Earth the continents are definitely along for the ride. These are called convection currents.

Answer 3

The lithosphere includes the Crust and the uppermost Mantle. This is the hard and rigid outer layer of the Earth. These plates behave elastically on a time scale of thousands of years and deform through brittle failure. The Lithosphere is then broken onto Tectonic Plates. The Plate motion is driven by friction between the convective currents of the Asthenosphere and the more rigid overlying Lithosphere. Plate movement also springs from the single idea that present continents formed a single land mass and subsequently drifted apart causing ruptures in the Plates

Answer 4

The Earth's lithosphere is made up of rigid tectonic plates that are composed of the crust and upper part of the mantle. While the lithosphere can move horizontally on the asthenosphere beneath it, it does not flow like a liquid because it is solid and is too cool and rigid to exhibit fluid-like behavior.

Answer 5

The Earth's lithosphere does not flow because it is very rigid. It only floats like ice on top of the asthenosphere.