The Perito Moreno Glacier flows down from the Cordillera like a large river of ice. On some occasions, it has crossed Canal de los Témpanos (Iceberg Channel) reaching the shore opposite the valley of the glacier. The Glacier forms an ice dike that blocks the flow of the water from Brazo
Rico (Rico Arm Channel) toward Argentinian Lake, damming up this section of the lake.
When the water level of the Rico Arm rises, the pressure it exerts on the Glacier wall gradually increases undermining the ice until a tunnel is opened and the water begins to flow into Argentinian Lake. Then once again the two lake basins become connected.
This natural cataclysm lasts a day or two, with spectacular ice detachments and is undoubtedly one of the most exciting and marvelous phenomena in the world.
When the two basins are leveled, the glacier comes forth once again obstructing the channel and the whole process starts again.
These cycles are not regular and since the last breaking, recorded on February 17, 1988, this phenomenon has not happened again.
Thanks to the El Calafate's Municipal Tourism Office - 491-090