Antarctica’s Lake Vanda is composed of four layers of water, each one saltier and warmer
than the one above it. Two hundred feet beneath the surface, the salty brine water is a
warm seventy-seven degrees Fahrenheit. Lake Vanda is only one of the many saline lakes
in the ice-free valleys of the Transantarctic Mountains.
Because they have no outlets, they are fed by melted glacier streams carrying small
amounts of salts and other minerals. Through the centuries, large quantities of these
salts have accumulated in these lakes, settling in layers with the saltiest at the
bottom from lack of circulation. The ice covering the lakes serve to warm the water -
vertical crystals in the ice conduct light down to the bottom, where it is absorbed by
the salty brine and generates heat.
Among the lakes in this group is “Mummy Pond,” which was named for the mummified seals
found near its shores. Some are as old as 3,000 years.