Question

At what depth from the earth's surface, the Gutenberg Discontinuity is positioned in the interior of the earth?

• A. 3900 km
• B. 2900 km
• C. 1900 km
• D. 900 km

Hint:

The Gutenberg Discontinuity is the boundary that separates the earth's mantle from the outer core.

Answer 1

The Correct Option is B

Step 1: Identify the boundary.
The Gutenberg Discontinuity is the surface that separates the mantle above from the outer core below.

Step 2: Recall how it is found.
At this depth P-waves suddenly slow down and S-waves stop, because the outer core behaves like a liquid.

Step 3: Picture the layers.
Going inward we pass the thin crust, then the thick mantle, and the base of the mantle marks this discontinuity.

Step 4: Use the accepted depth.
This boundary lies about 2900 km below the surface.

Step 5: Check the options.
Among the choices 2900 km is the standard mantle to core depth.

Step 6: Conclude.
The Gutenberg Discontinuity is at about 2900 km depth.
\[ \boxed{2900\ \text{km}} \]