The present work concerns a study on the radiation and propagationof seismic body waves. Based on a reformulated seismic raytheory and supplemented by the results of several associatedboundary value problems, a method of body wave equalization isdescribed which enables the extrapolation of body-wave fields fromone point to another.
Applications of the above method to studies of earthquakesource mechanism and earth's structure, specifically its anelasticity,are presented. The findings for two deep-focus earthquakes can besummarized by: (1) a displacement dislocation source, or anequivalent double couple, can generally explain the observed radiationfields, (2) the source time functions can be explained by abuild-up step (1 - e -t/τ)H(t), and τ appears to be longer for largerearthquakes, (3) the total energy calculated from equalized spectrumsis: for the Banda Sea earthquake (M = 6-1/4 - 6-3/4), E = 1.01x1022ergs; and for the Brazil earthquake (M = 6-3/4 - 7), E = 2.56x1023ergs.
From the spectral ratios pP/P and P/P, it is found (1) thatthe upper 430 km of the mantle has an average Qɑ = 105, (2) that Qɑincreases very slowly until depth of about 1000 km, and (3) thatQɑ rises rapidly beyond a depth of 1000 km, remains a high valuein the lower mantle and drops sharply toward the core-mantle boundary.
