Which of the following statements with reference to Glacial trough is/are correct ? 1. Alpine glaciers strip valleys of their soil, regolith and sediment to form glacial troughs. 2. When the sea level is below the floor of a glacial trough, the seawater enters as the ice front recedes, creating a fiord. Select the answer using the code given below :

Glacial troughs are U-shaped valleys formed by the movement of alpine or valley glaciers. Statement 1 is correct as alpine glaciers deepen and widen existing V-shaped valleys by stripping away soil, regolith, and sediment through processes like scouring and plucking [1]. This erosional activity is uniform horizontally and vertically due to the glacier's heavy mass [2]. Statement 2 is also correct regarding the formation of fjords (or fiords). When a glacial trough is excavated below sea level, the subsequent recession of the ice front allows seawater to enter and inundate the valley. These features are characterized as very deep glacial troughs filled with seawater, common in high-latitude coastal regions like Norway [1]. Thus, both statements accurately describe the geomorphological processes associated with glacial troughs and their submerged counterparts.

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > Glacial Valleys/Troughs > p. 55
2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 17: Major Landforms and Cycle of Erosion > Glacial Trough > p. 231