Changes in sub-glacial and bedrock hydrology by retreating glaciers in Svalbard

The ongoing retreat of glaciers in Svalbard potentially exposes a permafrost-free glacier forefield (talik), which in certain cases also can become exploited by CH4-saturated groundwater.  In order to understand potential gas transfer to forefields linked to changing groundwater recharge and subglacial pressures, we present a coupled model for ice-dynamics, sub-glacial water flow and a geo-thermal groundwater-permafrost model, all included and coupled together in the package Elmer/Ice. The thermo-mechanical ice-flow problem is solved using the Stokes equations, sub-glacial hydrology by GlaDS.  With the additional geo-thermal groundwater-permafrost model we are in a position to study the complete transient hydrological and thermal system from glacier surface - with prescribed moulin recharge - down to the sub-permafrost aquifer and can trace groundwater paths with a seasonal resolution. Along the well studied glacier Midtre Lovénbren we demonstrate the importance of producing consistent initial conditions (in particular for permafrost distribution) and show transient simulation results that are qualitatively able to reproduce observed seasonal outflows of subglacial water in the glacier forefield.