Multifrequency Inversion of Ps and Sp Receiver Functions: Methodology and Application to USArray Data

We image the thermochemical structure of crust and mantle underneath North American continent by inverting recordings P-to-s (Ps) S-to-p (Sp) converted seismic body waves (receiver functions [RFs]). Through careful data selection processing, we construct a multifrequency Ps (5-, 8-, 10 -s) Sp (10- 15- s) RF set from USArray recordings. The inversion is interfaced with petrological phase equilibria computations to build self-consistent radial velocity density models for waveform simulations. Inverted are combined through back-projection along raypaths interpolation tomographic images structure. clustering analysis identify three major tectonic regions based on structure: tectonically active West (TAW), central transition region (CTR), cratonic-orogenic East (COE). TAW chemically more fertile Mg# ∼ 0.90 (molar = Mg/(Mg + Fe)) characterized an elevated potential temperature 1490 ± 27°C relative COE, which depleted (Mg# 0.91) colder (1419 27°C). CTR intermediate COE. find significant thermochemically induced topography associated base lithosphere (±90 km), while zone mostly influenced thermally 410-km discontinuity (±15 km). In contrast, 660-km discontinuity, where variations only ±5 km, reflects complex interplay. To place results in context, thermobarometric estimates basaltic rocks across western United States integrated inversions produce thermal model underlying mantle.