---
title: "Magnitude versus intensity of earthquake"
subject: "Engineering Geology I"
chapter: 2
key: "semester_3/engineering_geology_i:magnitude-versus-intensity-of-earthquake"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/magnitude-versus-intensity-of-earthquake
site: BCT Engineering
---

# Magnitude versus intensity of earthquake

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

- Asked in: 2063 Baisakh (old course), 2 marks
- Video: [Earthquake 101 - Intensity vs Magnitude](https://www.youtube.com/watch?v=316IohzAy18) — Earth Diary
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/magnitude-versus-intensity-of-earthquake
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-2

## Question

Differentiate between magnitude and intensity of earthquake.

## Short answer

Magnitude is a single instrumental measure of energy released at the focus (Richter scale). Intensity is a descriptive measure of damage and felt effects at a location (Mercalli scale), decreasing with distance from the epicentre.

## Answer

| Basis | Magnitude | Intensity |
|---|---|---|
| Meaning | Energy released at the focus | Effects and damage at a place |
| Basis of measurement | Seismograph record | Observed effects on people, buildings, ground |
| Scale | Richter (logarithmic), open-ended | Modified Mercalli, I to XII |
| Value per earthquake | One value | Different at different places |
| Depends on distance | No | Yes, decreases with distance |
| Nature | Objective, instrumental | Subjective, descriptive |
| Example | Gorkha 2015: about 7.8 | Epicentral area: about IX-X |

## Check yourself

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

1. Magnitude differs from intensity because magnitude measures:
   A. Damage at a place, whereas intensity measures energy
   B. Distance to the epicentre, whereas intensity measures depth
   C. Energy released at the focus, whereas intensity measures effects at a place
   D. Duration of shaking, whereas intensity measures frequency
   Answer: C. Magnitude is energy at the source; intensity is local effect. (Key point: Meaning)

2. Which statement is true?
   A. Intensity has one value per earthquake; magnitude varies with place
   B. Magnitude has one value per earthquake; intensity varies from place to place
   C. Both vary with distance
   D. Neither depends on the earthquake
   Answer: B. Intensity decreases with distance, magnitude does not. (Key point: Variation)

3. Which scales are used?
   A. Magnitude: Mohs; intensity: Richter
   B. Magnitude: Mercalli; intensity: Richter
   C. Magnitude: Richter (logarithmic); intensity: Modified Mercalli (I to XII)
   D. Magnitude: Mercalli; intensity: Mohs
   Answer: C. Richter for magnitude (instrumental), Mercalli for intensity (descriptive). (Key point: Scales)

## Related in Engineering Geology I

- [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

- [Magnitude and intensity of earthquake](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Aearthquake-magnitude-intensity) — Engineering Geology II, chapter 5, asked 12×