While wintertime snow rarely falls on this part of the ice sheet, strong winds are constantly relocating snow onto new dunes, and eroding the surface of others. When the wind lifts the snow overhead, diffusing the light of the sun into a flat gray haze, you completely lose your ability to discern variations in the snow surface. It is easy to find yourself suddenly stepping off a new sharp-edged bank, or tripping over a low, hard dune that's appeared along a familiar route. The surface is constantly in flux.
One of our tasks is to monitor accumulation and ablation on the snow surface. About a kilometer from the station, out in an expanse of undisturbed snow, there's a forest of bamboo poles, all bedded into the ice sheet, row after row, like a strange, failed plantation. Once a week, I suit up, ski out to the bamboo forest, and measure the height of each pole. There are a lot of them. Measuring and taking notes are jobs suited to a partnership, and both Yuki and Jason offered to join me. We set off into the wind, following a life-line of bamboo flags into the gray shroud of blown snow. The snow surface fluctuated from the brittle styrofoam-like pack of the icesheet to the soft, fluted forms of fresh dunes, and the skiing was correspondingly variable. In time, the bamboo forest resolved itself on the ice ahead of us, and, as it offered scant protection, we sheltered up just shy of its edge, with our backs to the wind, to prepare our gear and warm up. When ready, we tracked back and forth along the stakes, measuring and making notes, an hour's work, then skied back across the ice and dunes.
Although some dunes grow and others shrink, the overall snow level in the bamboo forest is decreasing in this cold, dry time of year: the snow is probably being worn away by wind erosion and lost to sublimation. The real accumulation--maybe a meter a year--will take place in the relatively warmer months. Though the curvature is imperceptible, we're at the domed top of the icesheet, the accumulation zone, where the ice sheet gains more water than it loses each year: an area of net growth. From here, gravity forces the ice to slowly flow towards the coastlines, where melting, erosion and evaporation exceed precipitation, and where glacial ice is extruded through fjords into the sea.
