Empty valleys were formed as the glacial ice melted and retreated up the valley; thus, they generally show how much the glacier has shrunk.  Findel, Gorner, Zmutt, and Furgg glaciers all show empty valleys.  Hiking up an empty valley is a convincing way to appreciate the extent of a glacier's shrinkage in length, width, and thickness in such a short time in response to climate change. 

 

The empty valley of the Findel Glacier shown above dramatically illustrates how much thickness the glacier has lost.  The ridges in this photograph tower over 200 ft above the empty valley that was once filled with ice.