New insights into the cooling of the oceanic lithosphere from surface-wave tomographic inferences

How oceanic plates cool and thicken with age remains a subject to debate, with several thermal models supported by apparently contradictory data. Combining a novel imaging technique that balances resolution and uncertainty with finite-frequency surface-wave measurements (Latallerie et al., Seismica, 2025), we build tomographic model SS3DPacific to revisit the cooling style of the oceanic lithosphere beneath the Pacific ocean (Latallerie et al., GRL, 2026). Resolution analysis indicates a strong vertical smearing that biases estimates of the apparent lithospheric thickness, limiting the ability to discriminate between the half space and plate cooling models. Laterally, a pattern of anomalous bands in seismic velocity aligned with fracture zones points to additional lateral complexities in the lithosphere, complicating simple age-trend analyses.