The moment magnitude scale (MMS; denoted explicitly with M w or Mw, and generally implied with use of a single M for magnitude) 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.Similar to the local magnitude scale (M L ) defined by Charles Francis Richter …

The moment magnitude scale – Mw or M w – developed by Kanamori (1977) and Hanks & Kanamori (1979), 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. Seismic moment is measured in Newton-meters (Nm or N·m ...

Earthquake size, as measured by the Richter Scale is a well known, but not well understood, concept. The idea of a logarithmic earthquake magnitude scale was first developed by Charles Richter in the 1930's for measuring the size of earthquakes occurring in southern California using relatively high-frequency data from nearby seismograph stations.

USGS Earthquake Hazards Program, responsible for monitoring, reporting, and researching earthquakes and earthquake hazards

The Richter scale / ˈ r ɪ k t ər / —also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale —is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 paper, where he called it the "magnitude scale". This was later revised and renamed the local magnitude scale, …

The moment magnitude scale is based on the total moment release of the earthquake. Moment is a product of the distance a fault moved and the force required to move it. It is derived from modeling recordings of the earthquake at multiple stations. Moment magnitude estimates are about the same as Richter magnitudes for small to large earthquakes.

Moment magnitude, Richter scale - what are the different magnitude scales, and why are there so many? Earthquake size, as measured by the Richter Scale is a well known, but not well understood, concept. The idea of a logarithmic earthquake magnitude scale was first developed by Charles Richter in the 1930's for measuring the size of earthquakes ...

The moment magnitude scale is the only scale capable of reliably measuring the magnitudes of the largest, most destructive earthquakes (that is, greater than magnitude 8). The moment magnitude scale was designed to produce a more accurate accounting of moment magnitude (MW), also called moment magnitude scale, quantitative measure of an ...

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 or strength as measured by seismic …

The Richter scale is a base-10 logarithmic scale, meaning that each order of magnitude is 10 times more intensive than the last one. In other words, a two is 10 times more intense than a one and a three is 100 times greater. In the case of the Richter scale, the increase is …