Entry: macroseismic scale
URI: https://registry.epos-eu.org/ncl/FAIR-Incubator/tcs-SEISMO/21
Macroseismic intensity assessments assign integer numerals to observed physical damages and perceived motions, thus classifying the shaking strength observed at a site. When these intensity classes are arranged in a systematic and mutually linked reasonable way they form a macroseismic scale. Macroseismic intensity scales can be considered as an analogue to the 12-degree Beaufort wind-strength scale which is also based on perceptions and physical effects. The first, also internationally widely used macroseismic intensity scale was the ten-degree Rossi-Forel Scale of 1883. The scale of Sieberg (1912, 1923) became the foundation of all modern twelve- degree scales. A later version became known as the Mercalli- Cancani-Sieberg Scale, or MCS Scale (Sieberg, 1932). It was translated into English by Wood and Neuman (1931), becoming the Modified Mercalli Scale (MM Scale), and after an extensive revision by Richter (1958) the �Modified Mercalli Scale of 1956� (MM56). Since the 1960s, the Medvedev-Sponheuer- Karnik Scale (MSK Scale, Sponheuer and Karnik, 1964) was widely used in Europe. It was based on the MCS, MM56 and previous work of Medvedev (1962) in Russia, but greatly developed the quantitative aspects of the scale. Since the late 1990s the much more elaborated European Macroseismic Scale 98 (EMS-98; Gr�nthal, 1998) has essentially replaced the usage of the old MSK scale although content-wise the EMS is more or less compatible with it. A more recent modification of the MM Scale, termed MMI, was proposed by Stover and Coffman (1993). All these scales have twelve degrees of intensity. Only the scale used in Japan, the JMA intensity scale, uses less degrees, originally 6, and since recent modifications (JMA 1996, 2009) 10 degrees.