What is the difference between the Mercalli and Richter scale in terms of measuring earthquakes?

Question

Explain how each one measures the earthquakes force or how it works. Which one is the most direct measurement of energy?

Answer 1

The Richter Scale is the best known scale for measuring the magnitude of earthquakes. The magnitude value is proportional to the logarithm of the amplitude of the strongest wave during an earthquake. A recording of 7, for example, indicates a disturbance with ground motion 10 times as large as a recording of 6. The energy released by an earthquake increases by a factor of 30 for every unit increase in the Richter scale.

Scales for measuring earthquakes...

The Richter Scale is the best known scale for measuring the magnitude of earthquakes. The magnitude value is proportional to the logarithm of the amplitude of the strongest wave during an earthquake. A recording of 7, for example, indicates a disturbance with ground motion 10 times as large as a recording of 6. The energy released by an earthquake increases by a factor of 30 for every unit increase in the Richter scale.



The Modified Mercalli Intensity Scale is commonly used in the United States by seismologists seeking information on the severity of earthquake effects. Intensity ratings are expressed as Roman numerals between I at the low end and XII at the high end.  These ratings indicate the damage done and are descriptive.

The Intensity Scale differs from the Richter Magnitude Scale in that the effects of any one earthquake vary greatly from place to place, so there may be many Intensity values measured from one earthquake. Each earthquake, on the other hand, should have just one Magnitude, although the several methods of estimating it will yield slightly different values.

Answer 2

http://en.wikipedia.org/wiki/Mercalli_in...

http://en.wikipedia.org/wiki/Seismic_sca...

http://en.wikipedia.org/wiki/Richter_mag...

http://en.wikipedia.org/wiki/Seismometer