abstract: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.
The spectraof the far-fieldbody wavedisplacement for variousmagnitudeearthquakesare derived, usinga two-dimensionalfaultingmodelfeaturing a rectangular fault.