The moment magnitude scale – Mw or M w – developed by Kanamori (1977), is based on an earthquake's seismic moment, M 0, a measure of how much work an earthquake does in sliding one patch of rock past another patch of rock.
Moment magnitude scale. The moment magnitude scale ( MMS; denoted explicitly with Mw or Mw, 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. It was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori.
e. The Modified Mercalli intensity scale ( MM, MMI, or MCS ), developed from Giuseppe Mercalli 's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the effects of an earthquake at a given location, distinguished from the earthquake's inherent force ...
Seismic magnitude scales. Seismic magnitude scales are used to describe the overall strength or "size" of an earthquake. These are distinguished from seismic intensity scales that categorize the intensity or severity of ground shaking (quaking) caused by an earthquake at a given location. This short article about science can be made longer.
Like many other intensity scales, ESI 2007 uses the basic structure of twelve degrees of seismic intensity and is designed for application during field surveys immediately after the seismic event. However, the definitions of intensity degrees in ESI 2007 are based on the observation of distribution and size of environmental effects produced by ...
Each is valid for a particular frequency range and type of seismic signal. In its range of validity, each is equivalent to the Richter magnitude. Because of the limitations of all three magnitude scales (ML, Mb, and Ms), a new more uniformly applicable extension of the magnitude scale, known as moment magnitude, or Mw, was developed. In ...