The North Aral Sea (Kazakh: Soltüstık Aral teñızı) is the portion of the former Aral Sea that is fed by the Syr Darya River. It split from the South Aral Sea in 1987–1988 as water levels dropped due to river diversion for agriculture.
In 1925 a large site containing numerous fossils of the Oligocene was discovered near the village of Akespe by the northern shore of the Aral Sea.
The Syr Darya, historically known as the Jaxartes (/dʒækˈsɑːrtiːz/ jak-SAR-teez; Ancient Greek: Ἰαξάρτης), is a river in Central Asia. The name, which is Persian, literally means Syr Sea or Syr River. It originates in the Tian Shan mountains in Kyrgyzstan and eastern Uzbekistan, and flows for 2,256.25 kilometres (1,401.97 mi) west and north-west through Uzbekistan, Sughd province of Tajikistan, and southern Kazakhstan to the northern remnants of the Aral Sea. It is the northern and eastern of the two main rivers in the endorheic basin of the Aral Sea, the other being the Amu Darya.
During the Soviet era, extensive irrigation projects were constructed around both rivers, diverting their water into farmland and causing, during the post-Soviet era, the virtual disappearance of the Aral Sea, once the world's fourth-largest lake. The point at which the river flows from Tajikistan into Uzbekistan is, at 300 m (980 ft) above sea level, the lowest elevation in Tajikistan.
The Aral Sea was an endorheic salt lake lying between Kazakhstan to its north and Uzbekistan to its south, which began shrinking in the 1960s and had largely dried up into desert by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhstan and the Karakalpakstan autonomous region of Uzbekistan. The name roughly translates from Mongolic and Turkic languages to "Sea of Islands", a reference to the large number of islands (over 1,100) that once dotted its waters. The Aral Sea drainage basin encompasses Uzbekistan and parts of Afghanistan, Iran, Kazakhstan, Kyrgyzstan, Tajikistan, and Turkmenistan.
Formerly the third-largest lake in the world with an area of 68,000 km (26,300 sq mi), the Aral Sea began shrinking in the 1960s after the rivers that fed it were diverted by Soviet irrigation projects. By 2007, it had declined to 10% of its original size, splitting into four lakes: the North Aral Sea, the eastern and western basins of the once far larger South Aral Sea, and the smaller intermediate Barsakelmes Lake. By 2009, the southeastern lake had disappeared and the southwestern lake had retreated to a thin strip at the western edge of the former southern sea. In subsequent years occasional water flows have led to the southeastern lake sometimes being replenished to a small degree. Satellite images by NASA in August 2014 revealed that for the first time in modern history the eastern basin of the Aral Sea had completely dried up. The eastern basin is now called the Aralkum Desert.
The South Aral Sea is a lake in the basin of the former Aral Sea that formed in 1987 when that body divided in two, due to diversion of river inflow for agriculture. In 2003, the South Aral Sea itself split into eastern and western basins, the Eastern Sea and the West Aral Sea, connected by a narrow channel (channel bed at an elevation of 29 m (95 ft)) that balanced surface levels but did not allow mixing, and in 2005 the North Aral Sea was dammed to prevent the collapse of its fisheries, cutting off the only remaining inflow to the southern lakes. In 2008, the Eastern Sea split again, and in May 2009 had almost completely dried out, leaving only the small permanent Barsakelmes Lake between the Northern and Western Seas and increasing the expanse of the Aralkum desert. In 2010, it was partially filled again by meltwater, and by 2014 was once again dry. The West Aral Sea has some replenishment from groundwater in the northwest.