---
title: "Body waves versus surface waves"
subject: "Engineering Geology I"
chapter: 2
key: "semester_3/engineering_geology_i:body-waves-versus-surface-waves"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/body-waves-versus-surface-waves
site: BCT Engineering
---

# Body waves versus surface waves

Engineering Geology I · Chapter 2: Basic Reviews of the Earth

- Asked in: 2062 Baisakh (old course), 2 marks; 2066 Bhadra (old course), 2 marks (asked 2 times)
- Video: [Body waves and Surface waves](https://www.youtube.com/watch?v=yxZneDg5CJc) — Sadie Kingsbury
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/body-waves-versus-surface-waves
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-2

## Question

Differentiate between body waves and surface waves (seismic waves).

## Short answer

Body waves travel through Earth's interior: P-waves are compressional, S-waves are shear, both faster and arrive first. Surface waves travel along the surface, are slower, have larger amplitude, and cause more damage; they include Love and Rayleigh waves.

## Answer

| Basis | Body waves | Surface waves |
|---|---|---|
| Travel | Through the interior of the Earth | Along the Earth's surface only |
| Types | P-waves (primary) and S-waves (secondary) | Love (L) and Rayleigh (R) waves |
| Speed | Faster; P fastest | Slower |
| Arrival | First | Last |
| Particle motion | P: push-pull; S: up-down/side to side | Rolling or horizontal shaking |
| Amplitude | Smaller | Larger |
| Damage | Less | Most destructive to structures |
| Medium | P through solid, liquid, gas; S only solids | Surface layers |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which waves arrive first?
   A. Surface waves
   B. Love waves
   C. Rayleigh waves
   D. Body waves (P fastest)
   Answer: D. Body waves are faster. (Key point: Arrival)

2. Most destructive to structures:
   A. Surface waves
   B. P-waves
   C. S-waves
   D. None
   Answer: A. Larger amplitude. (Key point: Damage)

3. S-waves travel only through:
   A. Liquids
   B. Solids
   C. Gases
   D. All media
   Answer: B. P travels through all. (Key point: Medium)

## Related in Engineering Geology I

- [Seismic waves and earthquake mechanism](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aseismic-waves-and-earthquake-mechanism) — Engineering Geology I, chapter 2
- [Earthquake intensity, magnitude, seismic waves](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aearthquake-intensity-magnitude-seismic-waves) — Engineering Geology I, chapter 2

## Related in other subjects

- [Microwaves versus acoustic or seismic waves](https://www.bctengineer.com/question.md?key=semester_7%2Frf_and_microwave_engineering%3Amicrowaves-vs-acoustic-waves) — RF and Microwave Engineering, chapter 1, asked 2×
- [Seismic waves](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Aseismic-waves) — Engineering Geology II, chapter 5, asked 4×
- [Surface versus sub-surface investigation](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Asurface-vs-subsurface-investigation) — Engineering Geology II, chapter 4, asked 3×
- [Surface versus sub-surface drainage](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Asurface-vs-subsurface) — Transportation Engineering I, chapter 4, asked 2×