Transdimensional Bayesian Attenuation Tomography of the Upper Inner Core

Following the linearized attenuation tomography from our previous study (Peji et al., 2017, ), we perform hierarchical transdimensional Bayesian tomography of the upper approximate to 400km of the inner core, using 398 globally distributed t estimates. The results are in good agreement with the ones obtained through linearized tomography: they show more complex attenuation pattern than the purely hemispherical one, and the noise estimated from the hierarchical inversion is in good agreement with estimates obtained from the Discrepancy Principle in the previous study. The attenuation pattern we observe gives more weight to the geodynamical models that couple the thermal anomalies of the lowermost mantle to the inner core boundary.