Body wave magnitude

Earthquakes
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Fault movement Volcanism Induced seismicity
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Epicenter Hypocenter Shadow zone Seismic wave P-wave S-wave
Measurement
Seismic scales Seismometer Earthquake duration magnitude
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Shear wave splitting Adams–Williamson equation Flinn–Engdahl regions Earthquake engineering Seismite Seismology
Earth Sciences Portal Category • Related topics

Body wave magnitude ( $m_b$ ) is a way of determining the size of an earthquake, using the amplitude of the initial P-wave to calculate the magnitude. The P-wave is a type of body wave that is capable of traveling through the earth at a velocity of around 5 to 8 km/s, and is the first wave from an earthquake to reach a seismometer. Because of this, calculating the body wave magnitude can be the quickest method of determining the size of an earthquake that is of a large distance from the seismometer.

Limitations in the calculation method mean that body wave magnitude saturates at around 6-6.5 $m_b$ , with the figure staying the same even when the moment magnitude may be higher.

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Measuring the Size of an Earthquake

Seismic scales

Modern scales

Intensity scales	Environmental Seismic Intensity scale (ESI) European Macroseismic Scale (EMS) Liedu Medvedev–Sponheuer–Karnik (MSK) Modified Mercalli (MM) Shindo

Magnitude scales	Body wave magnitude Duration magnitude Local magnitude (Richter scale) Moment magnitude Surface wave magnitude

Historical scales

Body wave magnitude

See also

External links