Donggi Cona
Lake of China
From Wikipedia, the free encyclopedia
Lake Donggi Cona (also Donggei Cuona or Dongxi Co) is a freshwater lake located 4090 m above sea level at the northeastern Tibetan Plateau.
| Donggi Cona | |
|---|---|
Lake Donggi Cona with ice cover | |
  Donggi Cona | |
| Location | Qinghai, China |
| Coordinates | 35°17′N 98°32′E |
| Catchment area | 3,174 km2 (1,225 sq mi) |
| Basin countries | China |
| Surface area | 229 km2 (88 sq mi) |
| Max. depth | 90 m (300 ft) |
| Surface elevation | 4,090 m (13,420 ft) |
Geology and water chemistry
The lake basin is a tectonic pull-apart structure situated at the highly active Kunlun fault. It is characterised by a 92 m deep graben structure in the deeper western part of the lake basin, and a more shallow eastern part which is filled up with fluvial sediments.
During different episodes of the last ice age, the lake level was 24 to 57 m lower than today, and the lake was a closed system without outflow. With rising lake levels during the Holocene, an outflow developed ca. 4300 years ago, turning the lake into an open system.[1][2]
Since ca. 6800 years, the lake is an oligotrophic freshwater lake, with oxygen supply down to the lake bottom and a mean pH of 8.6. A higher primary productivity than at present and brackish conditions were inferred for the late glacial to mid Holocene period.[3][4]