Subproject 3: Dynamic of the grounding line at the 79°N Glacier

This subproject aims to investigate tidal effects on the movement of the grounding line. This line denotes the transition between the floating ice tongue and the grounded ice of the 79°N Glacier (79NG, Nioghalvfjerdsfjordenbreen). A viscoelastic material model is used to solve the momentum balance with finite elements. Nonlinearities of basal sliding and viscous deformation result in an asymmetry of the ice outflow across the grounding line. With purely viscous material models these nonlinearities cannot be represented and hence the outflow is underestimated. The extension to take the viscoelastic model provides the basis for reasonable future forecasts of the glacier to sea-level rise. Additionally, the variation of the basal topography of the floating ice tongue due to bending is determined to examine its impact on ocean dynamics in the fjord.