Before the introduction of Richter scale, the measurement of earthquakes was done using the Mercalli Scale developed in Italy by Giuseppe Mercalli in 1902. Mercalli scale involves the use of observations and estimation of the intensity by people who experienced the earthquake. The features to be observed include the effects on buildings, human beings and the earth surface in general. The initial scale by Giuseppe had a scale of 1 to 10 and was later revised to 12. A scale of one means that the intensity of the earthquake is low, and the effect is not felt while a scale of twelve indicates that the quake strong and its effects are disastrous (Heiligman, 2002).
The Mercalli scale is inferior and not scientific in comparison to the Richter scale because the measurements depend on merely observations. The scale of the earthquake may be exaggerated by the witness thus giving misleading information. In addition, the intensity of the damage may not give a clear indication about the strength of the earthquake. Factors, which hinder accuracy of the scale, include the design of the buildings, the distance of the epicenter, and the type of surface (sand or rock) (Heiligman, 2002). Various designs of buildings offer different resistance to the quake and the distance between the building and the epicenter determines the extent of the damage.
Charles Richter invented the Richter scale in 1934 and it is far much superior compared to the Mercalli scale. The Magnitude of the Ritcher Scale is based on scale of logarithm (base 10). Unlike the mercalli scale, which relies on opinions of people, Richter scale measures the ground movements with the help of a seismograph (Heiligman, 2002). The accuracy of the measurements is not compromised by the geographic conditions of a place. Furthermore, the Richter scale measures very small earthquakes, which are then expressed in negative numbers
Reference
Heiligman, D. (2002). Earthquakes. New York: Scholastic.
