Lithospheric thickness beneath the Pitcairn hot spot trail as inferred from Rayleigh wave dispersion

We have determined the S-velocity model beneath the Pitcairn hot spot trail from Rayleigh wave phase velocities in order to examine the plate reheating model, in which the lithosphere is expected to be thinned by reheating due to a hot spot. The Rayleigh wave dispersion for the Pitcairn hotspot trail was measured by the two-station method. The phase velocity dispersion obtained for the Pitcairn hot spot trail is consistent with oceanic upper mantle models with lithospheric ages corresponding to the Pitcairn hot spot trail. The dispersion data were inverted for S-velocity structure using a hybrid method combining a grid search method and a non-linear inversion method. The lithospheric thickness was constrained to be from 50 to 80 km, which is consistent to the thickness of the corresponding age, indicating that the oceanic lithosphere is not anomalously thinned beneath the studied region.