Colloquium: Matthew Siegfried

Deep, dark, and wet: Dynamic hydrology beneath the Antarctic ice sheet

Research over the past decade has revealed a dynamic hydrological environment beneath the Antarctic ice sheet, with implications for regional ice velocity, grounding-line stability, and fluxes of freshwater and nutrients to the Southern Ocean. Hidden beneath 10s to 1000s of meters of ice, these enigmatic hydrological systems are poorly understood, largely due to the short temporal window (five years) of the observational record. Moreover, there is minimal overlap between observations of subglacial hydrology and the processes an evolving water system may impact, leaving the relationship between basal water and the larger ice-ocean-sediment system in Antarctica unclear. I will present new airborne and satellite observations that extend the current record of active subglacial hydrology and explore the variability of Antarctic subglacial hydrological systems. I will then discuss the impacts of an evolving basal-water system on ice dynamics, and the on-going development of improved models to describe subglacial pathways for water transport. Finally, I will highlight two novel (to glaciology) methods we will deploy this field season—magnetotellurics and a fiber-optic-based distributed temperature sensor—to help quantify other aspects of the subglacial water system that have never been observed.