Why does snow take thousands of years to become glacier ice on the Antarctic plateau?

The transformation of snow into glacier ice is a process of densification driven by the weight of overlying snow, which causes snow grains to round, sinter, and eventually recrystallize into interlocking crystals. This process is highly dependent on temperature and moisture; in warmer, wetter environments, the presence of liquid water significantly accelerates the rate of change.1

On the Antarctic plateau, however, the environment is extremely cold and dry, often described as a cold desert with very low annual precipitation. Because these temperatures remain well below the melting point, the processes that facilitate rapid densification—such as melting and refreezing—are largely absent. Consequently, the snowpack densifies much more slowly. While the transition from snow to glacier ice can occur in just a few years in warmer climates, the lack of heat and moisture on the Antarctic plateau means the process requires burial to depths of approximately 150 meters and can take several thousand years to complete.123