Don Juan Pond, also called Lake Don Juan, is a small and very shallow hypersaline lake in the west end of Wright Valley (South Fork), Victoria Land, Antarctica, 9 km west from Lake Vanda. It is the saltiest body of water on earth with a salinity level of over 40%!
Don Juan Pond was discovered in 1961. It was named for two helicopter pilots, Lt Don Roe and Lt John Hickey, who piloted the helicopter involved with the first field party investigating the pond. On that initial investigation, the temperature was - 30 °C (- 22 °F) and the water remained in a liquid state.
Don Juan Pond is a shallow, flat-bottom, hyper-saline pond. It has greater salinity than the Dead Sea or even Lake Assal (Djibouti) (the same is true for Lake Vanda and perhaps other lakes in the McMurdo Dry Valleys). It has been claimed that the salinity in Don Juan Pond is over 18 times the ocean's salinity, compared to that of the Dead Sea at about 8 times that of the ocean. The fact that it is the only one of the Antarctic hypersaline lakes that almost never freezes is an indication of its top rank in salinity among the world's lakes.
|Sampling in the Don Juan Pond|
The calculated composition for its water is CaCl2 3.72 mol/kg and NaCl 0.50 mol/kg, at the temperature of -51.8°C. That would be equivalent to 413 g of CaCl2 and 29 g of NaCl per kg of water.