New measurements of inner core attenuation

The nature and properties of the inner core has been a topic of keen interest since its discovery as a solid body by Lehmann in 1936. Since then, there have been numerous studies into its (isotropic and anisotropic) velocity and attenuation structure. These models typically feature strong hemispherical and layered structures, which dominate the interpretations of these models.

In this study, we focus on the attenuation structure of the inner core: energy that is lost inelastically, i.e. not through elastic scattering or redistribution. Here, we will demonstrate the progress we have made in creating a data set of new measurements of attenuation in the inner core from a variety of seismic phases (but especially PKPdf-PKPbc) with a focus on improving the spatial distribution of observations from previous studies using earthquakes from 2018--2025. We go on to benchmark our results against those of Pejic et al (2017), who used 400 high quality dt* measurements to invert for attenuation structure in the uppermost 400 km of the inner core.