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 MercalliCancani-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; Grünthal, 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, since recent modifications (JMA 1996, 2009) now 10 degrees. See Chapter 12 of this Manual, the specific entries in this glossary for the specific scales and Musson et al. (2010) for a comparison between the scales and a discussion on their evolution