Lago Argentino
The Lago Argentino is the biggest freshwater lake in Argentina, with a surface area of 1,466 km2 (maximum width: 20 mi). It has an average depth of 150 m, and a maximum depth of 500 m.
The lake lies within the Los Glaciares National Park, in a landscape with numerous glaciers and is fed by the glacial meltwater of several rivers, the water from Lake Viedma brought by the La Leona River, and many mountain streams. Its drainage basin amounts to more than 17,000 km. Waters from Lago Argentino flow into the Atlantic Ocean through the Santa Cruz River.
The glaciers, the nearby town of El Calafate and the lake itself are important touristic destinations. The lake in particular is appreciated for fishing. Perch, common galaxias, "puyen grande", lake trout and rainbow trout — in both migratory and sedentary forms — are all found.
Source: en.wikipedia.org/wiki/Lago_Argentino - 03.06.2010
Iceberg in the Lago Argentino
The reason for the blue colour of some icebergs is not yet definitely claryfied. Probably it is connected with seawater, which first of all freezes and then comes to the surface because of a turning of the iceberg.