Wednesday, November 15, 201712:00 PM - 1:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Observations of ocean stratification below an Antarctic ice shelf
Carolyn BraneckyUC Santa Cruz
Ocean-driven melting of ice shelves is a potential trigger for ice loss from Antarctica. However, due to the difficulty in accessing the sub-ice-shelf ocean cavity, the relationship between ice-shelf melting and ocean conditions is poorly understood. In my talk, I will present the first oceanographic observations from the deep interior of Antarctica’s largest ice shelf, collected through a 750-m-deep ice borehole. Stratification has developed within this 10-m-thick water column as a result of buoyancy flux from ice melting. This stratification is prone to double-diffusive convection and bears some similarity to double-diffusive staircases observed elsewhere. The influence of double-diffusive convection on heat and salt transfer to the ice-shelf base may be underappreciated. By combining these observations with simultaneous radar measurements of ice-shelf melting, we gain insight into the efficiency of heat and salt transfer from the turbulent boundary layer to the ice-shelf base. These heat and salt fluxes approach the limit of molecular diffusion and melting is slow, 7 cm yr-1.
Host: Angel Garcia