Question

The Mohorovicic Discontinuity separates which two layers of the Earth?

• A. Crust and Mantle
• B. Mantle and Outer Core
• C. Outer Core and Inner Core
• D. Lithosphere and Asthenosphere

Hint:

Important Earth interior discontinuities:

• \textbf{Mohorovičić Discontinuity (Moho)} $\rightarrow$ Crust and Mantle
• \textbf{Gutenberg Discontinuity} $\rightarrow$ Mantle and Outer Core
• \textbf{Lehmann Discontinuity} $\rightarrow$ Outer Core and Inner Core

Remember: \textbf{Moho = Crust–Mantle boundary}.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The interior of the Earth is divided into compositional layers: the crust, mantle, and core.
Seismic waves change velocity abruptly as they pass through materials of different densities. These abrupt changes are called discontinuities.
Step 2: Detailed Explanation:
The Mohorovičić discontinuity, often simply called the "Moho," is the boundary that separates the Earth's crust from the underlying mantle.
It was discovered in 1909 by Croatian seismologist Andrija Mohorovičić, who observed that seismic waves suddenly speed up at this depth due to the higher density of mantle rocks (like peridotite) compared to crustal rocks.
Other major discontinuities include:
- Gutenberg Discontinuity: Separates the Mantle and Outer Core.
- Lehmann Discontinuity: Separates the Outer Core and Inner Core.
Step 3: Final Answer:
The Mohorovicic Discontinuity separates the Crust and Mantle.