South Aral Sea Syr Darya, would be diverted in order to irrigate cotton and food crops in Kazakhstan and Uzbekistan. In 1986, due to an accelerated loss of water, the Aral Sea was split into northern and southern parts; the northern part is the current North Aral Sea. In 2007, the western basin had a salinity of 70 g/l and the eastern basin 100 g/l. Once the water level falls below the connecting channel (elevation 29 m), the salinities can be expected to diverge further. Under current conditions, the eastern basin may receive water from the Amu Darya in wet years, fluctuating in
Normal height chosen. The Soviet Union and many other Eastern European countries have chosen a height system based on normal heights, determined by geodetic precise levelling. Normal gravity values are easy to compute and "hypothesis-free", i.e., one does not have to know, as one would for computing orthometric heights, the density of the Earth's crust around the plumbline. Normal heights figure prominently in the theory of the Earth's gravity field developed by the school of M.S. Molodenskii. The reference surface that normal heights are measured from is called the quasi-geoid, a representation of "mean sea level" similar to the geoid and close