Other destinations Sparse snow builds ice sheet Even though most of Antarctica is covered by thousands of feet of ice, it's a desert. In fact, annual precipitation is about like that of the Sahara Desert. While a few places near the coast receive more than 6 feet of snow a year, most of the continent has only 2 to 12 inches. This is because the air is so cold that it can carry virtually no moisture to create snow. Antarctica's ice averages around 8,000 feet thick because the ice has been building up for millions of years.
Temperatures are too cold for the snow to melt.
A little sublimates directly into the air and the wind blows a little away - but it mostly ends up elsewhere on the ice sheet. In other words, most of the snow that falls on Antarctica stays there. The crystals are often dendrites , which leave plenty of room for air when they first settle to the surface. But as snow continues piling up, the crystals are pressed closer and closer together. As the ice is squeezed the crystals merge to become larger and larger.