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Charles Francis Richter (/ ˈ r ɪ k t ər /; April 26, 1900 – September 30, 1985) was an American seismologist and physicist.He is the namesake and one of the creators of the Richter magnitude scale, which, until the development of the moment magnitude scale in 1979, was widely used to quantify the size of earthquakes.
v. t. e. The Modified Mercalli intensity scale (MM, MMI, or MCS) measures the effects of an earthquake at a given location. This is in contrast with the seismic magnitude usually reported for an earthquake. Magnitude scales measure the inherent force or strength of an earthquake – an event occurring at greater or lesser depth. (The " Mw ...
That gave the Mercalli Scale, as well as the European MSK-64 scale that followed, a quantitative element representing the vulnerability of the building's type. [10] Since then, that scale has been called the Modified Mercalli intensity scale (MMS) and the evaluations of the seismic intensities are more reliable.
By using subjective damage-based scales for earthquake intensity like the Modified Mercalli intensity scale or MSK-64 intensity scale and the objective numerical gradation method of the Richter scale as models, he proposed a simplified 1–5 grading scale as a guide for areas that do not have hurricane building codes. The grades were based on ...
The Mercalli intensity scale uses personal reports and observations to measure earthquake intensity but PGA is measured by instruments, such as accelerographs. It can be correlated to macroseismic intensities on the Mercalli scale [ 3 ] but these correlations are associated with large uncertainty.
Earthquakes. The moment magnitude scale (MMS; denoted explicitly with M or Mw or Mwg, and generally implied with use of a single M for magnitude [1]) is a measure of an earthquake 's magnitude ("size" or strength) based on its seismic moment. Mw was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori.
An earthquake occurred in the region of Abruzzo, in central Italy, at 03:32 CEST (01:32 UTC) on 6 April 2009.It was rated 5.8 or 5.9 on the Richter magnitude scale and 6.3 on the moment magnitude scale; [9] its epicentre was near L'Aquila, the capital of Abruzzo, which together with surrounding villages suffered the most damage.
The scale was first proposed by Sergei Medvedev , Wilhelm Sponheuer (East Germany), and Vít Kárník (Czechoslovakia) in 1964. It was based on the experiences being available in the early 1960s from the application of the Modified Mercalli intensity scale and the 1953 version of the Medvedev scale, known also as the GEOFIAN scale.