Question map
Which one of the following statements regarding S-waves is not correct?
Explanation
Statement 2 is incorrect because S-waves are actually more destructive to structures than P-waves. While surface waves are the most destructive overall [4], among body waves, S-waves cause more damage than P-waves because they have greater amplitudes and produce both vertical and horizontal ground motion. S-waves exert lateral or shear forces on structures like buildings and overpasses, which are often designed to withstand vertical gravity but not strong horizontal loading. Other statements are correct: S-waves are approximately 1.7 times slower than P-waves [4]. They are transverse waves that require rigid bonds to propagate, meaning they can only travel through solids and are blocked by the liquid outer core [3]. This specific limitation—the S-wave shadow zone—provided the primary seismological evidence that the Earth's outer core is liquid [1].
Sources
- [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 2: The Origin and Evolution of the Earth > Earthquake Waves > p. 20
- [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 4: Earths Interior > Why Do P-Waves Travel Faster Than S-Waves? > p. 61
- [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 4: Earths Interior > S Wave Shadow Zone > p. 63
- [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 4: Earths Interior > Secondary Waves (S-Waves) > p. 62