Satellite observations and modelling of surface meltwater flow and its impact on ice shelves

Ice shelves slow the movement of the grounded ice sheets that feed them. This reduces the rate at which ice sheets loose mass to the oceans and contribute to sea-level rise. But ice shelves can be susceptible to collapse, particularly when surface meltwater accumulates in vulnerable areas. Meltwater lakes can create and enlarge fractures within the ice shelves, thereby triggering or hastening ice-shelf collapse. The drainage of water across the surface of Antarctica and where it accumulates has received little attention. This drainage was assumed to be insignificant, but recent work shows that meltwater can drain for tens of kilometers across ice-shelf surfaces and access areas that would otherwise not accumulate meltwater. Surface meltwater drainage could play a major role in the future stability of ice sheets. This drainage is the focus of this project.

The team will develop and test physics-based mathematical models of water flow and ice-shelf fracture, closely informed by remote sensing observations, to examine (1) how do surface drainage systems respond to inter-annual changes in surface melting, (2) how this drainage is influenced by ice dynamics and (3) whether enlarged drainage systems could deliver meltwater to areas of ice shelves that are vulnerable to water-driven collapse. The project will examine these issues by (1) conducting a remote sensing survey of the structure and temporal evolution of meltwater systems around Antarctica, (2) developing and analyzing mathematical models of water flow across ice shelves, and (3) developing and testing simple models of ice-shelf fracture. An outreach activity will make use of the emerging technology of Augmented Reality to visualize the dynamics of ice sheets in three dimensions to excite the public about glaciology at outreach events around New York City. This approach will be made publicly available for wider use as Augmented Reality continues to grow in popularity.

Three aspects of the project will produce data and code that will be archived in USAP-DC:
1. Mapped ice-shelf drainage system characteristics.
2. Computed continent-wide fields of ice-shelf vulnerability to hydrofracture.
3. An open source augmented reality ice sheet app.