The Anatomy of a Glacier's Amphitheater
The Cirque de Gavarnie is a massive, horseshoe-shaped rock amphitheater carved by glacial erosion. Its limestone walls rise up to 1,500 meters from the cirque floor to the surrounding peaks, which exceed 3,000 meters in elevation. The cirque has a circumference of about 6.5 kilometers and a width at its top of around 3,000 meters. This structure was formed over millions of years by the repeated scraping and plucking action of glaciers during the Quaternary period.
At the center of the cirque is the Grande Cascade de Gavarnie, mainland France's highest waterfall. It has a total drop of 422 meters, with its single tallest plunge measuring 281 meters. The waterfall is fed by melting snow and a small glacier on the Spanish side of the border. The water seeps underground before emerging at the top of the cliff face. While its average annual flow is 3 cubic meters per second, this can increase to 200 cubic meters per second in the summer during intense snowmelt.