MODEL RELEASED. Glaciology research. Glaciologists using a Heucke steam drill to bore a hole into the Marmaglaciaren glacier, Swedish Lapland. The drill uses gas to produce steam to melt the ice around the long probe. Once the hole has been drilled to the desired depth, an ablation stake is inserted. This is a stake of known depth that is inserted at the end of the snow accumulation season (winter). At the end of the melting season (summer), the glaciologists will return and measure how much ice has melted by comparing the level to that of the stake. Comparing this value with the amount of snow accumulated gives the mass balance, the net change in the glacier over a year.