Waveform Modeling of the Crust and Upper Mantle Using S, Sp, SsPmP, and Shear-Coupled PL Waves

Abstract

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Waveform modelling of teleseismicS, Sp, SsPmP, and shear-coupled PL waves for crust- and upper-mantle velocity structure beneath Africa

“…The SPL phase samples a broader region beneath the seismographic station (Fig. 1b) compared to the Sp phase, and its generation and propagation is affected by seismic velocity gradients, V p / V s ratios, impedance contrasts across the Moho, and thicknesses of the layers inside the Earth (Baag & Langston 1985; Pulliam et al 2002). With the exception of the direct S phase, all the other phases discussed above appear prominently only on the vertical and radial component seismograms at teleseismic distances (Fig.…”

“…The technique is complementary to the receiver function method in that it retains its advantages, uses a different part of the seismogram, is sensitive to both P ‐ and S ‐wave velocities directly, and obtains helpful constraints in model parameters in the vicinity of the Moho. The method is particularly beneficial if the objective of using the velocity model is to determine the location and focal depths of small, regional seismic events (Pulliam et al 2002). The primary reason for this is the characteristic feature of the shear‐coupled PL phase, which this technique models wherever available, that it samples a broader area beneath the seismic station thereby representing a broad regional average (Zhao et al 1996; Zhao & Frohlich 1996; Pulliam et al 2002).…”

“…The method is particularly beneficial if the objective of using the velocity model is to determine the location and focal depths of small, regional seismic events (Pulliam et al 2002). The primary reason for this is the characteristic feature of the shear‐coupled PL phase, which this technique models wherever available, that it samples a broader area beneath the seismic station thereby representing a broad regional average (Zhao et al 1996; Zhao & Frohlich 1996; Pulliam et al 2002). Moreover, the technique also has the ability to invert for the P ‐ and S ‐wave velocities independent of each other.…”

Prediction of Elastic Properties Within CO2 Plume at Sleipner Field Using AVS Inversion Modified for Thin‐Layer Reflections Guided by Uncertainty Estimation

“…The algorithm and procedure Journal of Geophysical Research: Solid Earth of the VFSA method are given in detail in Stoffa (1991, 2013), Pulliam and Sen (2004), and Agrawal et al (2015). VFSA has established its efficiency, acceptance, and ability to converge more quickly than other methods while producing similar results in earlier geophysical applications (Agrawal et al, 2015;Ingber, 1989;Pulliam & Sen, 2004;Zhao et al, 1996). We describe the inversion algorithm and its input parameters used in this work in Appendix C.…”

“…The model parameters that we invert are P wave velocity (V P ), S wave velocity (V S ), density, and layer thickness of multiple layers. The algorithm and procedure Journal of Geophysical Research: Solid Earth of the VFSA method are given in detail in Stoffa (1991, 2013), Pulliam and Sen (2004), and Agrawal et al (2015). VFSA has established its efficiency, acceptance, and ability to converge more quickly than other methods while producing similar results in earlier geophysical applications (Agrawal et al, 2015;Ingber, 1989;Pulliam & Sen, 2004;Zhao et al, 1996).…”