What is the lithosphere?

What is the lithosphere?

• A. The outer rigid shell of Earth
• B. The partly molten layer beneath the mantle
• C. The liquid metal core
• D. The lower mantle

Answer: (A)

The lithosphere is the outermost, rigid shell of Earth. It includes the crust plus the uppermost part of the mantle and behaves as a stiff, brittle layer that forms the tectonic plates. Beneath it lies the asthenosphere, a softer, partially molten region that allows these plates to move. The option describing a partly molten layer under the mantle would refer to the asthenosphere, not the lithosphere. The liquid metal core is the outer core, and the lower mantle is deeper and not the rigid shell that makes up the plates. So the outer rigid shell best describes the lithosphere.

The lithosphere is the outermost, rigid shell of Earth. It includes the crust plus the uppermost part of the mantle and behaves as a stiff, brittle layer that forms the tectonic plates. Beneath it lies the asthenosphere, a softer, partially molten region that allows these plates to move. The option describing a partly molten layer under the mantle would refer to the asthenosphere, not the lithosphere. The liquid metal core is the outer core, and the lower mantle is deeper and not the rigid shell that makes up the plates. So the outer rigid shell best describes the lithosphere.