GEOLOGY

Detailed explanation-1: -Although numerousintensity scales have been developed over the last several hundred years to evaluate the effects of earthquakes, the one currently used in the United States is the Modified Mercalli (MM) Intensity Scale. It was developed in 1931 by the American seismologists Harry Wood and Frank Neumann.

Detailed explanation-2: -Note: The Modified Mercalli scale is designed to describe the effects of an earthquake, at a given place, on natural features, on industrial installations and on human beings. The intensity differs from the magnitude which is related to the energy released by an earthquake.

Detailed explanation-3: -In the United States, we use the Modified Mercalli (MMI) Scale. The Mercalli Scale is based on observable earthquake damage.

Detailed explanation-4: -Richter Scale. While the Mercalli scale describes the intensity of an earthquake based on its observed effects, the Richter scale describes the earthquake’s magnitude by measuring the seismic waves that cause the earthquake. The two scales have different applications and measurement techniques.

Detailed explanation-5: -Although several scales have been developed over the years, the two commonly used today in the United States are the moment magnitude scale, which measures magnitude (M), or size, and the Modified Mercalli scale, which measures intensity.