Antarctic ice sheet (glacial period)
Maximum extent of the Antarctic ice sheet during glacial cycles, e.g. at 21,000 years before present. Extent and volume changes are closely linked with grounding line changes of the West Antarctic ice sheet due to sea level lowering. At the glacial maximum, the grounding line extended close to the continental shelf break almost everywhere. Ice over central East Antarctica was generally thinner than today and varied mainly in accordance with accumulation fluctuations. Color shadings are increments of 500 m ice thickness.