Glaciation and Coasts Answer either (i) or (ii) - Junior Cycle Geography - Question 2C - 2018

One significant feature formed by glacial erosion is a U-Shaped Valley.

Explanation of Formation

1. Initial Formation: During the last Ice Age, glaciers moved down pre-existing V-shaped valleys, which were carved by river erosion. The immense weight and movement of the ice caused the valley to deepen and widen over time.

2. Erosion Processes: The processes at play include:

   • Plucking: As glaciers moved, they plucked rock from the valley floor and sides. This is due to the freezing and thawing of water, which helps the ice grip onto the rock.
   • Abrasion: The glacier itself, carrying debris, grinds against the valley walls and floor, further deepening and smoothing the valley shape.

3. Final Result: By the time the glacier recedes, a distinct U-shaped valley is left behind, characterized by steep sides and a flat valley floor. This shape is markedly different from the original V-shaped river valley.

Diagram

(A labelled diagram should accompany the answer, depicting a U-shaped valley with annotations pointing out features such as the ice flow direction, the steep valley sides, and the flat valley floor.)