Question

Arrange the following Seismic discontinuities based on their depth of occurrence from shallow to deeper: A. Conrad discontinuity B. Repetti discontinuity C. Gutenberg discontinuity D. Lehmann discontinuity E. Mohorovicic discontinuity

• A. D, C, B, E, A
• B. A, D, B, C, E
• C. E, A, B, C, D
• D. A, E, B, C, D

Hint:

Remember the typical depths: Conrad ($\sim$20 km), Moho ($\sim$35 km), Repetti ($\sim$900 km), Gutenberg ($\sim$2900 km), Lehmann ($\sim$5100 km).

Answer 1

The Correct Option is D

Step 1: Concept
Seismic discontinuities and their depths.

Step 2: Meaning
Seismic discontinuities are boundaries within the Earth where there is a sudden change in velocity of seismic waves, helping us understand Earth's internal structure.

Step 3: Analysis
Approximate depths of each discontinuity:
• Conrad discontinuity (A): $\sim$15--20 km (within continental crust)
• Mohorovičić discontinuity (E): $\sim$35 km (crust--mantle boundary)
• Repetti discontinuity (B): $\sim$900 km (upper/lower mantle transition)
• Gutenberg discontinuity (C): $\sim$2900 km (core--mantle boundary)
• Lehmann discontinuity (D): $\sim$5100 km (inner/outer core boundary)

Step 4: Conclusion
From shallow to deeper: Conrad (A) $\rightarrow$ Mohorovičić (E) $\rightarrow$ Repetti (B) $\rightarrow$ Gutenberg (C) $\rightarrow$ Lehmann (D). Final Answer: (D)