Meltwater production due to strain heating in Storglaciaren, Sweden

[1] Storglaciaren, northern Sweden, is temperate in most parts except for a cold surface layer in the ablation zone. One of four possible sources for liquid water in temperate ice is melting due to strain heating. Velocity fields are calculated with an ice flow model, so that calculated and observed surface velocities agree. Meltwater accumulation is computed by integrating strain heating along trajectories starting at the surface in the accumulation area and ending at the cold-temperate transition surface in the ablation zone. The distribution of moisture content due to strain heating alone is mapped in a longitudinal section of Storglaciaren. Values reach more than 10 g of water per kilogram ice-water mixture in the lowest parts of the temperate domain. For this moisture content the rate factor is more than 3 times higher than for water-free ice, and therefore water production by strain heating is important for the modeling of temperate and polythermal glaciers.