Beneath Antarctica's Ross Ice Shelf a hidden ocean reveals new measurements

Researchers recorded four years of temperature, salinity and current data beneath the Ross Ice Shelf, finding systematic seasonal variations and persistent layered waters that partly isolate the ice underside.

Researchers obtained a four-year record of ocean conditions beneath the centre of the Ross Ice Shelf, one of the least-measured oceans on Earth. The ice shelf is the floating fringe that helps restrain Antarctica's land-based ice. Instruments reported temperature, salinity and currents beneath roughly 320 metres of ice and a 420-metre-deep cavity. The observations were collected as part of a multi-year project that began in 2016 and continued until contact with the instruments was lost in 2022. Key findings: - A four-year continuous record was collected beneath the central Ross Ice Shelf, with instruments operating longer than their expected two-year lifespan. - Measurements included temperature, salinity and currents under about 320 metres of ice and a 420-metre water column. - Data show systematic seasonal variations in water properties and persistent layering that appears to isolate the ice shelf underside from deeper, warmer waters. - Variations in the cavity align with changes in the Ross Sea Polynya and with sea-ice formation processes that occur hundreds of kilometres away. Summary: The new, unusually long record improves understanding of how subtle changes in the cavity beneath the Ross Ice Shelf relate to basal melting and to distant sea-ice processes. Undetermined at this time.