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Jan 1, 2016 · The amount of elastic energy released by an earthquake is measured on a magnitude scale (see Magnitude Measures ) whereas the effects of intensity of ground motion or “shaking” occurring at a given surface point are measured on an intensity scale. Seismologists use earthquake intensity as their most widely applicable measure of the size of ...
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.
However, not all of the energy released in an earthquake will necessarily be felt at the surface, depending on the earthquake's depth. In New Zealand, where earthquakes occur from near the surface right down to a depth of over 600 km, the Modified Mercalli intensity scale is a better indicator of an earthquake's effects on people and their ...
Earthquake Intensity Scale (Abridged). The Modified Mercalli Intensity (MMI) Scale is composed of increasing levels of intensity that range from imperceptible shaking to catastrophic destruction; levels of intensity are designated by Roman numerals. The MMI Scale does not have a mathematical basis; instead, it is a holistic ranking based on ...
Download Database (MS Excel format; 15MB) Introduction. Description of Database. Definition of Variables. History of Earthquake Intensity Scales. Collecting Data on Earthquake Intensity. References. Earthquake intensities are numerical values assigned to the effects of earthquakes on people and their works, and on the natural environment.
The Intensity 7 ( 震度7, Shindo 7) is the maximum intensity in the Japan Meteorological Agency seismic intensity scale, covering earthquakes with an instrumental intensity (計測震度) of 6.5 and up. [15] At Intensity 7, it becomes impossible to move at will. [13] The intensity was created following the 1948 Fukui earthquake.
So the intensity of an earthquake will vary depending on where you are. Sometimes earthquakes are referred to by the maximum intensity they produce. In the United States, we use the Modified Mercalli (MMI) Scale. The Mercalli Scale is based on observable earthquake damage.