Difference Between Richter Scale and Mercalli Scale

Richter Scale vs Mercalli Scale

Whenever an earthquake occurs (perhaps the deadliest of all natural disasters), experts use certain tools to measure seismic activities of the Earth and gauge the strength of the phenomenon. In relation to this, scales such as the Richter and Mercalli are used to give the public some insight and make advanced forecasting and warning measures.

Scientists have devised ways to measure the intensity of earthquakes. As such, an earthquake can be measured either by basing it on the seismic energy magnitude or by looking into the earthquake’s effects or intensity on the surroundings. Because of this, two popular scales were devised. The Richter scale is the ideal barometer for evaluating the overall seismic activity magnitude while the Mercalli scale is used for quake intensity. Other similar scales can be used to measure the intensity like the EMS scale, MSK scale, INQUA scale and Shindo scale. The two scales that are more commonly used in America are the Richter and Mercalli scales.

Historically, the Mercalli is an earlier scale which dates back to the 19th century. It was later modified by an Italian volcanologist named Giuseppe Mercalli in the early 1990s. Surprisingly, it was Charles Richter (the man who also devised the Richter scale) who was responsible for giving it its most updated form. Today, the Mercalli scale is completely known as the MMI scale or Modified Mercalli Intensity scale.

As mentioned, Charles Richter developed the Richter scale back in 1935. With the help of Beno Gutenberg (an associate of his), they made the most popular and commonly used seismic scale at present. This is most probably because the Richter scale is more objective in nature as it utilizes the findings generated by seismometers. Thus, numerical values help create logarithms. By contrast, the Mercalli scale is much more subjective.

The Richter scale has a 0 to 10 numerical range. The weakest earthquakes usually register values within 0 and 3.9. The middle level quakes fall from 5-5.9 while the stronger quakes land somewhere from 6-6.9. The most powerful of all seismic activities will be marked as 7 or greater. On the contrary, the MMI has 12 levels of intensity with level 1 being the least alarming characterized by minor tremors perceived by seismic instruments. The highest of which is level 12 which is described as total destruction. Thus it is known for its other term “cataclysmic level.”

Summary:

1.The Richter scale measures the seismic activity magnitude of an earthquake and other areas that can be measured numerically.
2.The Mercalli scale measures the intensity of the earthquake.
3.The Mercalli scale is an older scale that predates the Richter scale.
4.The Richter scale is more commonly used than the Mercalli scale.
5.The Richter scale is more objective as opposed to the more subjective Mercalli scale.

Sharing is caring!