Question

The "Discontinuity" that separates the Earth's crust from the mantle is known as?

• A. Gutenberg Discontinuity
• B. Mohorovičić Discontinuity
• C. Lehmann Discontinuity
• D. Conrad Discontinuity

Hint:

Remember the order of Earth's layers and their boundaries: Crust $\rightarrow$ \textbf{Moho} $\rightarrow$ Mantle $\rightarrow$ \textbf{Gutenberg} $\rightarrow$ Core $\rightarrow$ \textbf{Lehmann}.

Answer 1

The Correct Option is B

Concept: The Earth is composed of different layers: crust, mantle, and core. The boundaries separating these layers are called discontinuities, where there is a sudden change in seismic wave velocity due to differences in composition and density.

• Mohorovičić Discontinuity (Moho): Separates crust and mantle
• Gutenberg Discontinuity: Separates mantle and outer core
• Lehmann Discontinuity: Separates outer core and inner core
• Conrad Discontinuity: Separates upper and lower crust (not always distinct)

Step 1:Identify the boundary between crust and mantle.
The boundary where seismic waves suddenly increase in velocity marks the transition from the crust to the mantle.
Step 2:Match with the correct discontinuity name.
This boundary is known as the Mohorovičić Discontinuity, commonly called the Moho.