The ice bridge on the Perito Moreno Glacier in Argentina collapsed on Thursday, shortly before 11am. This came after several days of anticipation across the country and tourists from around the world ahead of the natural phenomenon, which affects the third largest mass of ice after the two poles.
The mass of ice forming a bridge between the two parts of the glacier, dividing Lake Argentino in the province of Santa Cruz, collapsed at 10.55, sending tons of ice crashing down onto the surface of the lake, 60 meters below.
The Perito Moreno is a naturally balanced glacier, which grows to form the bridge, preventing water from flowing from the southern arm of the Rico river to the Lake Argentino, through the Icebergs channel.
“The Rico river is blocked, which means its level rises until the force exerted by the water on the bridge is superior to the bridge’s weight. When the ice begins to move at some point along the support, the water begins to filter into it and the irreversible breaking process starts. This is not due to a mechanical fracture in the ice, but to the development of a subglacial channel,” states the Glaciarium, a highly respected scientific bureau in Argentina.
The Glaciarium experts summarized that “at first, the water is filtered through a small subglacial channel, which is enlarged as the water pressure continues to erode the tunnel. This process then rapidly expands as huge chunks of ice fall off spectacularly from the bridge into the channel below.”