Mercalli intensity scale Mercalli intensity scale The Mercalli intensity scale is a seismic intensity scale used for measuring the intensity of an earthquake. It measures the "effects" of an earthquake. It is distinct from the moment magnitude ("M") usually reported for an earthquake, which is a measure of the "energy" released (sometimes misreported as the Richter magnitude, "M"). The intensity of an earthquake is not entirely determined by its magnitude. It is not based on first physical principles, but is, instead, empirically based on observed effects. The Mercalli scale quantifies the effects of an earthquake on the Earth's surface, humans, objects of nature,
Rating scale at the ordinal level. Numbers indicate the relative position of items, but not the magnitude of difference. Attitude and opinion scales are usually ordinal; one example is a Likert response scale: Some data are measured at the interval level. Numbers indicate the magnitude of difference between items, but there is no absolute zero point. A good example is a Fahrenheit/Celsius temperature scale where the differences between numbers matter, but placement of zero does not. Some data are measured at the ratio level. Numbers indicate magnitude of difference and there is a fixed zero point. Ratios can be calculated. Examples include