Answer: Glacially carved valleys are U-shaped, with wide and deep profiles resulting from the erosional action of glaciers. They often exhibit unique features and are influenced by various factors, including glacier size, rock type, and climate. The correct answer is b) They are U-shaped.
Step-by-step explanation:
Glacially carved valleys are characterized by their U-shaped profile. Unlike rivers, which create V-shaped valleys through the erosional processes of water flow, glaciers reshape the landscape in a distinct manner.
As glaciers move, they exert immense pressure on the underlying rock and sediment. This pressure, combined with the abrasive action of rocks and debris within the glacier, scours and erodes the valley floor and sides. The result is a wide and deep valley with steep, straight sides.
Glacial valleys often exhibit features such as hanging valleys, cirques, and moraines. Hanging valleys are smaller valleys that intersect the main glacial valley but have a higher elevation, creating waterfalls or cascades. Cirques are bowl-shaped hollows at the head of the glacial valley, formed by the rotational movement of ice. Moraines are ridges of rock and sediment deposited by the glacier as it retreats.
It is important to note that glacial valleys can vary in size and shape depending on factors such as the size and movement of the glacier, the type of rock being eroded, and the climate. However, their characteristic U-shaped profile distinguishes them from V-shaped valleys created by rivers.