Using Figure 8 and your own knowledge, assess the role of frost action in the development of this landscape - AQA - A-Level Geography - Question 4 - 2019 - Paper 1

Frost action plays a significant role in the development of periglacial landscapes such as the one depicted in Figure 8.

1. Periglacial Features: The landscape is characterized by features such as permafrost, active layers, and frost heave. The interaction of water, soil, and frost creates distinct patterns that are prominent in periglacial regions. In the context of Figure 8, the presence of ice wedges indicates that frost action has led to the cracking and expansion of the ground. These features contribute to the distinctive polygonal patterns commonly found in periglacial zones.

2. Mass Movement and Thermal Dynamics: The landscape also showcases thermokarst formations, which occur when permafrost thaws, leading to subsidence and the creation of depressions filled with water. In late summer, as depicted in the image, thawing may further influence the hydrology and thermal dynamics of the area. Water pooling in these depressions can promote the growth of vegetation, altering the habitat.

3. Frost Weathering Processes: The freeze-thaw cycles are critical for weathering processes in this environment. Water infiltrates into cracks during warmer months, and upon freezing, it expands, exerting stress on the rocks and soil. Over time, this leads to the disaggregation of materials and contributes to the unique landscape forms. In Figure 8, the uneven surface may be a result of such frost weathering processes.

4. Influence on Hydrology: The high water table and numerous lakes in the landscape are consequences of frost action and permafrost dynamics. The presence of extensive permafrost layers modifies drainage patterns, resulting in the formation of ponds and lakes, as water accumulates in areas where the ground has subsided or been shaped by frost.

Overall, frost action, including freeze-thaw cycles, plays a central role in shaping the periglacial landscape in Figure 8, influencing features, hydrology, and geomorphological processes.