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Спутники
РН
SpaceX
Роскосмос
NASA
СпутникиРНSpaceXРоскосмосNASAWe present array‐scale (∼500 × 500 km) anisotropic shear‐velocity models from two Pacific ocean‐bottom seismometer (OBS) arrays of the OBS Research in the Convecting Asthenosphere (ORCA) experiment: Young ORCA (∼43 Ma) and Old ORCA (∼90 Ma). Rayleigh‐wave phase velocities spanning 5–150 s are combined with Love‐wave phase velocities from 5 to 10 s to constrain VSV $\left({V}_{SV}\right)$ and its azimuthal variation (G) $(G)$ to 300‐km depth, and radial anisotropy ξ=VSH/VSV2 $\xi ={\left({V}_{SH}/{V}_{SV}\right)}^{2}$ azimuthal VSH $\left({V}_{SH}\right)$ parameter E $E$ to ∼50 km depth. Both sites show a lithospheric lid over a low‐velocity zone, with lid thickness correlating with plate age, and positive ξ $\xi $ through the crust and upper lithosphere. Young ORCA has moderate lithospheric azimuthal anisotropy (|G| $\vert G\vert $ ∼ 3%) consistent with spreading‐parallel corner flow to ∼30–50 km, while Old ORCA displays weak (∼1%–2%), laterally variable lithospheric anisotropy...