[marginalia_nu]

I do think conversion is involved in generating these odd figures somehow. May not be the sole part, but the figure in the title is definitely an conversion that's sprouted additional sigfigs.

644 km is 400,000 miles (within 0.04% error).

[mkl]

Typo there: 400 miles. The actual paper's abstract [1] says "~650-km". In a skim through I didn't see anything that might correspond to the strange 1600km depth.

[1] https://www.nature.com/articles/s41467-023-36074-2