The Determination of P-wave Attenuation Values in the Earth's Mantle

Direct determinations of the P-wave attenuation parameter, Qp, in the Earth's mantle are made using changes in the form of P-wave amplitude spectra as a function of distance. Two independent sets of experimental data from axisymmetrical surface sources are used: (1) 288 records of narrow-band SVKM seismometers from 19 events, and (2) 75 records of wide-band SVK seismometers from seven larger events. The average Qp value in the depth interval between 100 and 760 km is found to be 710 and in the interval 760–2900 km to be between 1200 and 1330. The estimate of the accuracy of these results is given and the comparison with other authors' results of direct and indirect Qp determination is made.