Which scale assesses earthquakes based on the damage they cause?

• A. Modified Mercalli Scale
• B. Richter Scale
• C. Seismometer
• D. Moment Magnitude

Answer: (A)

The scale that assesses earthquakes by the damage they cause is the Modified Mercalli Scale. It focuses on the observed effects of shaking at a specific location—how people feel it, how buildings and objects respond, and changes to the environment. This makes it a practical measure of impact, not just how strong the earthquake was in terms of energy released. A quake with the same energy can cause very different levels of damage depending on how far you are from the epicenter, the depth of the focus, the type of ground, and the robustness of structures, all of which the Modified Mercalli Scale captures by describing intensity levels from I to XII.

In contrast, the Richter scale, or local magnitude, and the Moment Magnitude scale quantify energy released by the earthquake, not the observed damage at a site. A bigger number on these scales doesn’t always translate to more damage locally, because damage depends on many situational factors. A seismometer is the instrument that records ground motion, not a measure of damage.