Question

The Gutenberg discontinuity is located at:

• A. boundary between the Earth's crust and mantle
• B. within the mantle zone
• C. boundary between the Earth's mantle and core
• D. within the core zone

Hint:

Gutenberg = mantle-core boundary; S-waves stop here due to liquid outer core.

Answer 1

The Correct Option is C

To determine the correct location of the Gutenberg discontinuity, let's analyze Earth's internal structure and seismic evidence:

1. Understanding Earth's Layers:
Earth's interior is divided into distinct layers separated by seismic discontinuities:

• Crust-Mantle Boundary: Mohorovičić discontinuity (Moho)
• Inner Core Boundary: Lehmann discontinuity (~5,150 km depth)

2. Evaluating the Options:
- Crust-mantle boundary: Incorrect (this describes the Moho discontinuity)
- Within the mantle: Incorrect (the discontinuity is a boundary, not within a zone)
- Mantle-core boundary: Correct (separates solid mantle from liquid outer core)
- Within the core: Incorrect (the discontinuity marks the upper core boundary)

3. Key Characteristics:
The Gutenberg discontinuity: Occurs at ~2,900 km depth Marks where P-wave velocities drop sharply (due to liquid outer core) Corresponds to the core-mantle boundary (CMB) Named after seismologist Beno Gutenberg who identified it in 1914

Final Answer:
The Gutenberg discontinuity is located at the boundary between the Earth's mantle and core.