What are the 2 parts of the mantle?
Earth’s mantle is divided into two major rheological layers: the rigid lithosphere comprising the uppermost mantle, and the more viscous asthenosphere, separated by the lithosphere-asthenosphere boundary.
Why are rocks in asthenosphere easily deformed?
Because the lithosphere is floating in the asthenosphere which is more ductile than the brittle lithosphere, the soft asthenosphere can flow to compensate for any change in thickness of the crust caused by erosion or deformation.
Where is the crust the thickest?
The layer of rock that forms Earth’s outer surface. The crust is up to 32 Kilometers (20 miles – here to Stone Mountain) thick. The crust is made up of the continents and the ocean floor. The crust is thickest under high mountains and thinnest beneath the ocean.
Where does the asthenosphere start?
Below the lithosphere is the asthenosphere layer, a much hotter and malleable portion of the upper mantle. The asthenosphere begins at the bottom of the lithosphere and extends approximately 700 km into the Earth.
What causes the asthenosphere to move?
Heat from deep within Earth is thought to keep the asthenosphere malleable, lubricating the undersides of Earth’s tectonic plates and allowing them to move. Convection currents generated within the asthenosphere push magma upward through volcanic vents and spreading centres to create new crust.
Where is asthenosphere located?
mantle
What happens in the asthenosphere?
This process is called subduction. Since the lithospheric material is more rigid than the material in the asthenosphere, the latter is pushed outward and upward. During this movement of plates, pressure on the asthenosphere is reduced, melting occurs, and molten materials flow upward to Earth’s surface.
Where is the asthenosphere located Select all that apply?
Right below the crust In the lower mantle.