Global variation of body-wave attenuation in the upper mantle from teleseismic P wave and S wave spectra

We constrain the spatial variation of P-wave (t(P)*) and S-wave (t(S)*) attenuation by inverting 190,000 teleseismic P-and S-wave spectra up to 0.8 Hz. These spectra are derived from 250 deep earthquakes recorded at 880 broadband global and regional network stations. The variance and ratios of t(P)* and t(S)* values are consistent with PREM's upper mantle velocity and Q structures and conventional t(P)* and t(S)* values. High attenuation is resolved beneath stations in tectonically active regions characterized by high heat flow. Low attenuation marks stable continental regions. The maps of t(P)* and t(S)* correlate well with the variations of t(S)* computed and inferred from (1) the most recent surface-wave Q model and (2) a thermal interpretation of shear-wave velocity tomography. This indicates that maps of body-and surface-wave attenuation reflect intrinsic attenuation and variable temperature in the mantle. Citation: Hwang, Y. K., J. Ritsema, and S. Goes (2011), Global variation of body-wave attenuation in the upper mantle from teleseismic P wave and S wave spectra, Geophys. Res. Lett., 38, L08311, doi:10.1029/2011GL046812.