Linking Geothermal Heat Flux and Melt Rates in Thwaites Glacier, Antarctica

John DeSanto

Model output compared with actual ice layer depths
Model output (blue) compared with actual ice layer depths identified in radar data (red) for Thwaites Glacier, Antarctica.

The Thwaites glacier of the West Antarctic ice sheet (WAIS) is currently one of the most important glaciers to study because it has one of the highest ice discharges into the sea. It is unique because its bed rests almost entirely below sea level, a potential cause for alarm as this may cause the system to be unstable. In addition, a wide variety of factors influence the ice flow of Thwaites, which may include basal melt generated by subglacial volcanism. I have identified anomalous ice layer signatures within Thwaites glacier characteristic of high melt rates and will determine the geothermal heat flux that caused them by forward modeling the heat flow through an ice stream. If the layer signature is caused by a subglacial volcano, I will also determine whether the heat flux causing the feature is varying in time.

After modeling the ice flow in my region, I have determined that if my feature is indeed caused by geothermal heat flux, it is likely concentrated in a small area and varying in time. Shown is an example in which the heat flux was concentrated and became hotter gradually until reaching a peak before cooling down. This is similar to a possible magmatic intrusion. This process results in a decent fit for lower ice layers, but not for upper ice layers, suggesting that there is another process affecting the system.

Supervisor: Don Blankenship