Definitions for "Modified Mercalli Intensity Scale"
a system for measuring the intensity of an earthquake based on observation of its effects on an area, e.g., damage to structures.
A scale for measuring ground shaking at a site, and whose values range from I (not felt) to XII (extreme damage to buildings and land surfaces). (See intensity and Table 1.)
The Mercalli scale rates the intensity of shaking from an earthquake. The ratings vary from I (felt only under especially favourable circumstances) to XII (total destruction). Modified Mercalli (MM) Intensity Scale