Europa's surface is shaped by two competing processes: geological activity pushes material up from the subsurface ocean, and radiation from Jupiter's magnetosphere bombards and alters whatever is exposed. Both leave spectral signatures. Separating them requires decomposing the observed spectrum into independent contributions.
JWST NIRSpec-IFU observations, analyzed through spectral factorization, reveal that CO2 enrichment extends well beyond Tara Regio — the chaos terrain where it was first identified — across multiple chaos units in a lens-shaped pattern (arXiv:2603.10520). The CO2-enriched areas co-occur with anomalous ice-texture signatures, suggesting that the enrichment reflects not just emplacement from below but also retention-favorable near-surface microphysics.
The distinction matters for habitability. If CO2 is only emplaced — pushed up by geological activity — then its distribution maps the plumbing. Where you find CO2, there was recently active exchange with the ocean below. But if CO2 is also preferentially retained — surviving longer in regions with particular ice textures — then its distribution maps the ice physics, not the plumbing. The same spatial pattern carries different information depending on whether emplacement or retention dominates.
The lens-shaped distribution spanning multiple chaos units suggests both processes contribute. CO2 is emplaced through chaos terrain and then retained preferentially in areas where the ice microphysics protects it from radiolytic destruction. The carbon on Europa's surface is a record of two processes, not one — and reading the record requires separating the two.