The School of Earth and Atmospheric Sciences Presents Dr. Jamin Greenbaum, Scripps Institute of Oceanography

What’s Eating East Antarctic Ice shelves? Controls on Melting on the Two Primary Outlets of the Aurora Subglacial BasinThe Aurora Subglacial Basin (ASB) in East Antarctica contains at least 3.5 meters of eustatic sea level potential in ice grounded below sea level primarily draining through the Totten and Denman Glaciers located along the Sabrina and Knox Coasts, respectively. Grounded ice upstream of where Totten and Denman feed their respective ice shelves has been thinning faster than any other glacier systems in East Antarctica since the beginning of the satellite altimetry record and their grounding lines have been retreating since at least 1996. The ice within the ASB is believed to have collapsed and advanced multiple times since the onset of large scale glaciation so it is imperative to understand what is driving the contemporary changes.In this talk I will present recent international collaborative airborne geophysical experiments conducted near Totten and Denman Glaciers aimed at teasing out processes and boundary conditions likely to be influencing melting near where they go afloat at their grounding lines. We rely on ice-penetrating radar analyses of ice shelves to infer patterns of surface and bottom melting, and gravity and magnetics data to infer the shape of the seafloor where icebreakers or autonomous vehicles have not yet explored. The results, combined the closest ocean profiles from ships and instrumented marine mammals, suggest that Totten and Denman are vulnerable to ocean-driven retreat similar to thinning glaciers in West Antarctica but with different sensitivities that should be explored in sustained multidisciplinary exploration of these enigmatic systems.