Question

study the image of earth’s layers.
which statement correctly compares the thicknesses of earth’s layers?
○ earth’s mantle is thinner than its oceanic crust.
○ earth’s outer core is thicker than its mantle.
○ earth’s continental crust is thicker than its lithosphere.
○ earth’s lithosphere is thinner than its asthenosphere.
(image of earths layers with labels: asthenosphere 660 km, lithosphere 100 km, upper mantle, continental crust 30 - 40 km, oceanic crust 5 km, lower mantle, mantle, outer core, inner core with respective distance markings)

Explanation:

1. Check each option against the diagram:

• Option A: The mantle's total thickness is $2900\ \text{km}$, far thicker than the 5 km oceanic crust. Incorrect.
• Option B: The outer core is $2270\ \text{km}$ thick, while the mantle is $2900\ \text{km}$ thick. Incorrect.
• Option C: Continental crust is $30-40\ \text{km}$ thick, while the lithosphere is $100\ \text{km}$ thick. Incorrect.
• Option D: Lithosphere is $100\ \text{km}$ thick, asthenosphere is $660\ \text{km}$ thick. $100 < 660$, so this is correct.

Answer:

D. Earth's lithosphere is thinner than its asthenosphere.