Modeling subglacial drainage including ice uplift and free-surface flow in 2D

Numerical models of subglacial drainage have evolved to combine both distributed and channelized drainage in two dimensions, and have enabled many studies of subglacial hydrology and of its link to ice flow in glaciers and ice sheets. However, a key limitation in these models has been the inability to incorporate bounded subglacial water pressures, preventing the representation of the physical regimes of ice uplift and free-surface flow. We present a new subglacial drainage model, which extends the Glacier Drainage System (GlaDS) model to include subglacial water pressures that are bounded between atmospheric and ice overburden values. The new model includes a physics-based representation of pressurized subglacial flow, ice uplift, and free-surface flow and automatically handles the transitions between each regime domain. We demonstrate this model’s capabilities through the simulation of a rapid drainage of a supraglacial lake in Greenland, during which we observe the formation of a traveling subglacial water blister inducing ice uplift, and the partial emptying of the subglacial space at the glacier terminus near the end of the drainage.