Aralkum is the name given to the new desert that has appeared on the seabed once occupied by the Aral Sea. It lies to the south and east of what remains of the Aral Sea in Uzbekistan and Kazakhstan.

While the level of the Aral Sea has fluctuated over its existence, the most recent level drop was caused by the former Soviet Union building massive irrigation projects in the region. The consequent severely reduced inflow subsequently caused the water level in the Aral Sea to drop. While the North Aral Sea is presently rising thanks to a dike, the South Aral Sea is still^[when?] dropping, thus expanding the size of the desert.

The sands of the Aralkum are made up of a salt-marsh consisting of finely-dispersed sea depositions and remnants of mineral deposits, washed away from irrigated fields. The dusts which originate from it contain pollutants. The desert's location on a powerful east-west airstream has resulted in pesticides in the dust being found in the blood of penguins in Antarctica. Aral dust has also been found in the glaciers of Greenland, the forests of Norway, and the fields of Russia.