: In 1961 central Asia's Aral Sea
was the fourth largest lake in the world. At present, it has split in two and covers just one-tenth the area it did at its peak. The primary cause for the shrinking is the establishment and expansion of irrigation systems that draw water from the rivers feeding the lake. Although the northern of the two remaining lakes has recovered somewhat, the southern lake had been considered a lost cause. Now, carbon dating of cores taken from the exposed lakebed suggest the southern lake could recover as well. Sergey Krivonogov of the Institute of Geology and Mineralogy in Novosibirsk, Russia, and his colleagues discovered that between AD 400 and 600 the lake's surface was just 10 m above sea level, and between AD 1000 and 1500 it was just 29 m above sea level. In comparison, the surface was at 54 m in 1961. Currently, the northern lake is at 42 m, but the southern lake has split into three pieces, each less than 29 m above sea level.