Superfiscous sounds supracociate.

Results and video — recent Nature article.

Mantle depth of 3000 km ~0.5 Earth's radius. Circumference 40,000 km.

Solid. Flow by slow fiscous creep. v~cm/year.

Re~10-20 & 1023 momentum neglible. Infinite Prandtl number approximation.

Ra ~107 features ~100 km wide Need ~25km grid spacing 60 million grid points!

Viscosity strongly T-dependent. ~10x per 100K. Surface 'plates.'
Also non-linear, i.e., strain rate stress3

and it wouldn't surprise me if "fiscous" were a typo for "viscous".