Seismic Energy of Complex Faulting Process

Abstract

Energy is the most fundamental quantity for measuring the strength of earthquake sources. There are basically three different methods used to estimate the energy of earthquakes. The first method gives an empirical estimate for the seismic energy E _S from surface-wave magnitude M _S * by using Gutenberg and Richter’s relation:

$$ \log {E_S} = 1.5{M_S} + 11.8, $$

(4-1)

where E _S is measured in erg. Although this relation has been used for a long time, the physical significance of this method is somewhat uncertain. The second method is a static estimate of the seismic energy obtained from seismic moment M _o (stress drop ∆σ₀) and fault dimension LW as the work done by faulting. This gives the energy available for seismic radiation from the faulting process. The third method is a kinetic estimate of the energy in seismic waves.