[SSS17-P11] Screening for elastic multipathing effects on teleseismic body waves
Keywords:seismic attenuation, teleseismic body waves, upper mantle, seismic amplitudes, defocusing effects
Seismic waves propagating through heterogeneous material have observable and predictable effects on travel time and arrival amplitude. Body waves arrive earlier when traversing through faster material but also exhibit reduced amplitudes. Thus, if seismic energy is traversing a medium with wavespeed anomalies but uniform intrinsic attenuation, we expect to see early arrival times correlate with low amplitudes and high t* estimates. In contrast, if intrinsic attenuation dominates over multipathing, then we expect a different trend when plotting arrival time versus seismic amplitude. We explore the feasibility of using these trends as a preliminary screen for problematic regions that are more likely to be dominated by multipathing effects. We compare trends of arrival time and seismic amplitude for P-, S-, and SKS-phases at teleseismic distances. We introduce a multipathing scalar value to highlight regions where focusing and defocusing effects are expected to be problematic.