Soils in the Ross Sea Region of Antarctica

Abstract

The Ross Sea region of Antarctica contains the largest ice-free areas in Antarctica (about 6700 km2). Soils in the Ross Sea region have a mean annual temperature of about −15 to −25 °C and so all contain permafrost. Antarctic soils generally comprise: a stony desert pavement from which fine material has been removed, predominantly by wind erosion; an active layer that freezes and thaws each year; and underlying permafrost in which temperatures remain below 0 °C. The McMurdo Dry Valleys, described as a ‘cold desert’, are Antarctica’s largest continuous ice-free area, formed where evaporation exceeds precipitation. In some of the driest areas, there is not enough soil moisture to form ice-cement and the soils are described as having ‘dry permafrost’. However, in coastal areas, and areas where there is some input of snow or meltwater, the permafrost is ice-cemented, patterned ground features form at the land surface, and soils may contain lenses or wedges of ice. Soils range from having minimal weathering and soil development on active surfaces, such as wind-blown sand dunes and sites of fluvial activity, through to ancient soils on stable, older, higher altitude surfaces, with highly weathered desert pavements, and salt-rich layers in the soil.