Question

Sequentially arrange the reactions of observers and type of damage during an earthquake in the increasing order of earthquake intensity measured at Modified Mercalli Intensity (MMI) Scale.

A. Earthquake is felt quite noticeably indoors, especially on upper floors of buildings. Damage: No damage. Standing motor cars may rock slightly. 
B. Everyone runs outdoors. Noticed by persons driving motor cars. Damage: Considerable damage in poorly built or badly designed structures. 
C. Earthquake is not felt except by a few people under especially favorable circumstances. Damage: No damage. 
D. Earthquake is felt by nearly everyone, many awakened. Damage: Some dishes, windows broken, few cracks in plaster, unstable objects overturned. 
 

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

Hint:

Modified Mercalli Intensity (MMI) scale is qualitative and based on human perception and damage observation.

Answer 1

The Correct Option is B

Step 1: Understand MMI scale progression.
- Lowest: Very faint tremor, perceived by few individuals.
- Next: Tremor perceptible indoors, with minimal to no damage.
- Moderate: Widely felt tremor, causing minor damage (e.g., plaster cracks, falling objects).
- Higher: Intense shaking resulting in structural damage.

Step 2: Order the provided events.
- Event C: Lowest intensity (perceived only by a few).
- Event A: Moderate intensity (noticeable indoors, no damage).
- Event D: Stronger intensity (felt by most, minor damage).
- Event B: Highest intensity among the given events (severe shaking with structural damage).

Step 3: Final sequence.
The correct order is: C, A, D, B.