We studied the Holocene (past 11 700 years) to understand how the Greenland Ice Sheet has changed. Using 841 computer simulations, we tested different scenarios and matched them to historical ice elevation data, confirming our model's accuracy. Results show that Greenland's melting has raised sea levels by about 5.3 m since the Holocene began and by around 12 mm in just the past 500 years.

We present a new method to improve estimates of snowfall across Greenland, a crucial factor in predicting sea-level rise. Current climate models often misrepresent snowfall patterns, resulting in significant long-term errors. By using two million observations, our method corrects model errors and produces more accurate snowfall maps. The improved maps can help to reduce uncertainty in sea-level rise projections and enhance understanding of Greenland’s proximity to critical melting thresholds.

Ice fracture can cause glacier crevassing and calving. These natural hazards can also modulate the flow and evolution of ice sheets. In a new study, we use a new high-resolution dataset to determine a new failure criterion for glacier ice. Surprisingly, the strength of ice depends on the mode of deformation, and this has potential implications for the currently used flow law of ice.

Old snow (denoted as firn) accumulates in the interior of ice sheets and gets densified into glacial ice. Typically, this densification is assumed to only depend on temperature and accumulation rate. However, it has been observed that stretching of the firn by horizontal flow also enhances this process. Here, we show how to include this effect in classical firn models. With the model we confirm that softening of the firn controls firn densification in areas with strong horizontal stretching.

The Müller Ice Cap will soon set the scene for a new drilling project. To obtain an ice core with stratified layers and a good time resolution, thickness estimates are necessary for the planning. Here we present a new and fast method of estimating ice thicknesses from sparse data and compare it to an existing ice flow model. We find that the new semi-empirical method is insensitive to mass balance, is computationally fast, and provides good fits when compared to radar measurements.