How do hanging valleys form in glaciated mountains?

Hanging valleys are common in mountain landscapes once shaped by ice. During an ice age, a large main glacier can carve a deep U-shaped valley, while smaller side glaciers erode their valleys less intensely. When the ice melts, the side valley is left hanging above the main valley floor, often with a waterfall dropping from it. This difference happens because thicker ice exerts more pressure and has more erosive power. Classic examples can be seen in places such as Yosemite and the fjord landscapes of Norway.