In Siberia glaciers exist today only in arctic-maritime areas and high mountains. Former glaciers were more extensive than was generally believed prior to 1930 and had a similar distribution, closely related to high land. Their positions were determined partly by high land and partly by the prevailing storm tracks. The moisture from which the glaciers were built came from Atlantic, Arctic, and Pacific sources and was less abundant than the moisture from which the Scandinavian ice sheet was built. The Siberian glaciers were relatively thin, but ablation was generally small.
It is believed that the present distribution of frozen ground in Siberia bears little relation to the extent of former glaciation in that region. Multiple glaciation in several parts of Siberia is established. There seems to be no good basis for the belief that the Scandinavian and Siberian ice sheets were not synchronous, although it is clear that these two glaciers reached their maxima at slightly different times.
The distribution of former glaciers is shown in two accompanying maps.