Question

The asthenosphere is:

A. the layer only found under the continental crust
B. part of the upper mantle
C. a rigid zone in the lower mantle
D. a weak layer next to the core
E. all of the above

Answer 1

The asthenosphere is part of the upper mantle, characterized as a ductile, partially molten region that allows the movement of tectonic plates. It is not restricted to just beneath the continental crust, nor is it a rigid zone or adjacent to the core. The correct option is B.

Step-by-step explanation:

The asthenosphere is part of the upper mantle, which makes option B the correct answer to the question - The asthenosphere is part of the upper mantle. The asthenosphere is a mechanically weak and partially molten region of the earth's mantle that lies beneath the lithosphere and allows tectonic plates to move on top of it.

The lithosphere includes the earth's crust and the uppermost part of the mantle and is rigid and brittle. The asthenosphere, on the other hand, is ductile and can flow over time, accommodating the movement of tectonic plates. Unlike being just under continental crust or near the core, it extends beneath both the oceanic and continental crusts.