Intensity (earthquake)

from Wikipedia, the free encyclopedia

The intensity of an earthquake is the strength with which it affects people, structures and the environment in a given area. The intensity can be classified by means of different scales, for which either observations of macroseismic phenomena serve or instrumentally determined measured values ​​are used. In contrast to the magnitude , which provides information about the total energy released in a quake, a single quake can have different intensities depending on the distance from the epicenter and local conditions at different locations. These intensities can be represented with isoseismic maps .

Historical development

Early attempts to classify earthquakes are the works of Pompeo Schiantarelli in 1783, who in addition to numerous pictures of the effects of the Messina earthquake of 1783 also drew a map of the effects of the earthquake, and Domenico Pignatoro in 1788, who used a five-level intensity scale to describe the effects of the same earthquake put up. Another, also not widely used, scale was that of Peter Nikolaus Caspar Egen , who described the effects of an earthquake in Belgium in 1828.

The first commonly used scale was the Rossi-Forel scale (RF), which was published in its final form in 1883 after publications in 1874 and 1881. Due to the diversity of situations in Japan Fusakichi Omori wrote in 1900 Ōmoriskala while Giuseppe Mercalli in 1902 the first version of its Mercalli published. On this basis, several further developments of the Mercalli scale were published in the next decades, such as the Mercalli-Cancani-Scale and the Mercalli-Cancani-Sieberg-Scale (MC-S) from 1912 and 1923. In 1931 HO Wood and Frank Neumann translated the Mercalli-Cancani-Sieberg scale into the English language and called it Mercalli-Wood-Neuman scale (MWN) without any significant changes being made to it. This scale is still used in the United States today under the name Modified Mercalli Scale (MM-S). In 1956 Charles Francis Richter modified the Mercalli-Cancani-Sieberg scale thoroughly and also called it Modified Mercallis Scale , but with the addition of 1956 (MM-56).

In 1951, the JMA ( Japan Meteorological Agency ) developed the JMA scale based on the omori scale , which is still used today in Japan and by the Taiwanese CWB ( Central Weather Bureau ) in Taiwan .

In the USSR , Sergei Medvedev developed his Medvedev scale , which was adapted to local conditions in 1953, from which the GEOFIAN scale published in 1975 by the State Committee for Construction of the USSR developed. On the basis of the Medvedev scale as well as the MM-S and the MM-56, Sergei Medvedev, Wilhelm Sponheuer and Vít Kárník finally published the Medvedev-Sponheuer-Kárník scale (MSK-64), which was widely used for more than 25 years learned. The European Macroseismic Scale (EMS-98) has been developed on this basis since the beginning of the 1990s and was adopted in its current version in 1998.

Since 1999, the International Union for Quaternary Research (INQUA) has been developing a further scale that does not use damage to structures or the effects on people, but rather only the environmental effects of an earthquake to classify earthquakes. A first version was published in 2003 under the designation INQUA-Scale (INQUA-Scale) and finally in 2007 in its final version as ESI-Skala (Environmental Seismic Intensity Scale, ESI 2007).

literature

  • Roger MW Musson, Gottfried Grünthal, Max Stucchi: The comparison of marcoseismic intensity scales. In: Journal of Seismology. Volume 14, Issue 2, 2009, pp. 413–428, digital version online (PDF; 472 kB) at archives-ouvertes.fr (English).

Web links