Question

Hanging valleys are formed by the action of ____________.
A. Moving ice
B. Wind
C. Running water
D. None of these

Answer 1

Hint: A hanging gorge is a branch gorge that is higher than the core gorge. They are normally linked with U-shaped gorges when a branch glacier drifts into a glacier of larger size. A distinguishing attribute of glaciated mountain landscape, a hanging gorge is a branch to the main gorge which has been deeply battered by glacial ice, renouncing the branch gorge “hanging” above the main gorge.

Complete step-by-step solution:
The chief glacier corrodes a deep U-shaped gorge with approximately vertical sides while the branch glacier, with a smaller size of ice, makes a thinner U-shaped gorge. Since the exteriors of the glaciers were initially at the same height, the thinner gorge looks to be 'hanging' directly above the chief gorge. Often, waterfalls form at or near the opening of the upper gorge. Hanging gorges also ensue in fjord arrangements underwater. The branches of Sognefjord are, for example, much narrower than the key fjord. The mouth of Fjærlandsfjord is around 400 m deep while the key fjord is 1,200 m close. The entrance of Icefjord is only 50 m deep while the key fjord is about 1,300 m at a similar spot. Glaciated topography is not the only location of hanging brooks and gorges. Hanging gorges are also merely the result of changing rates of corrosion of the key gorge and the branch gorges. The changing rates of corrosion are linked with the configuration of the adjoining rocks in the diverse gorge sites. The branch gorges are battered and expanded by glaciers or corrosion at a more sluggish rate than that of the key gorge floor, hence the variance in the two gorges' depth rises over time. The branch gorge consists of more resilient rock then hangs over the key gorge.

Thus, option (C) is correct.

Note: Rivers form as the snow from the upper slants of the mountains liquefy, and stream along the hanging gorges. Upon reaching the entrance of the hanging gorge, where the gorge encounters the vertical walls of the key gorge, the river plunges to form a waterfall