Reconstructed ozone concentration in Antarctica based on the relative abundance of freshwater diatoms providing from a sediment core of Profound Lake/King George Island/Antarctica

Profound Lake (formerly known as Lago Glubokoe or Glubokoye) (62°11,066'S;058°54,413'W), is situated on Fildes Peninsula, the largest ice-free area (29 km2) of King George Island, the largest of the South Shetland Islands, located in the extreme southwestern part of the island. This lake lies 500 m from the base of the Collins glacier, close to the Uruguayan research base (Artigas) and Maxwell Bay. Morphologically it has a surface area of 90 km² and 14.7 m maximum depth. It's a holocenic, non-impacted, pro-glacial lake where diatoms are abundant and diverse.