Glaciation Flashcards

Question

What kind of river does a u-shaped valley have

Answer 1

tourists local residents hillwalkers/farmers passive active tourists HEP hillwalkers walkers and footpath

Answer 2

Pyramidal peaks are formed when several corries are eroded back-to-back on a single mountain. Glaciers play a significant role in shaping pyramidal peaks. As glaciers move down the slopes of the mountain, they erode and sculpt the rock, creating steep, U-shaped valleys or corries. The proximity of these corries can lead to the formation of sharp ridges known as arêtes. As glaciers continue to erode these arêtes and the surrounding rock, they may converge towards a central point at the mountain's summit, resulting in a pyramidal peak or horn. Frost action also contributes to the shaping of pyramidal peaks. Freeze-thaw cycles cause the rocks on the peak to fracture and break apart, creating the distinct pyramid-like shape.

Answer 3

Aretes form when two corries develop back-to-back. As these corries expand due to erosion, they carve deeper into the mountain, leading to a narrow ridge between them. One of the main erosive forces shaping aretes is frost shattering. This occurs when water infiltrates cracks in the rock, freezes, and expands. As this cycle repeats over time, larger pieces of rock are dislodged from the back wall of each corrie. The continuous frost shattering makes the ridge between the two corries increasingly jagged and pronounced, accentuating the knife-edge appearance. With the ongoing erosion and frost action, the ridge eventually takes on the distinctive, narrow profile of an arete, becoming a striking feature in the landscape.

Answer 4

Before glaciation: Snow accumulates in existing V-shaped river valleys. As snow layers continue to accumulate, air is expelled, leading to the compression of the snow into glacial ice. During glaciation: The glacier acts as a massive bulldozer, carving its path through the valley. The process of plucking, where the glacier freezes onto rocks and pulls them out, further steepening the valley sides. At the same time, abrasion caused by the embedded rocks and debris in the glacier scraping the valley floor, deepens and smooths the base. The immense force of the moving glacier can transform the landscape, converting interlocking spurs into truncated spurs. After glaciation: As temperatures increase, the glacier retreats, melting the ice. The aftermath of this process often leaves behind features like ribbon lakes or misfit streams in the newly-formed U-shaped valley. interlocking spurs are eroded and steep truncated spurs form

Answer 5

Water infiltrates the tiny pores in rocks. As it freezes, it expands, causing the rock to eventually crack or shatter. This action can lead to cracks in rocks widening by as much as 9%. Produces jagged rock surfaces.

Answer 6

* Before the ice age there is a small V shaped valley which has been eroded by a river (diagram 1) * During the ice age, a huge river of ice called a glacier flows into the valley from surrounding corries. * The glacier bulldozes through the valley, eroding the sides and bottom of the valley by plucking and abrasion (diagram 2) * Plucking is when the ice freezes to rocks and tears them from the land. * Abrasion is when rocks in the ice wear away the land like sand paper * The valley gets deepened, steepened, widened and straightened by erosion. * Freeze Thaw weathering also causes rocks to break up on the valley sides. * After the ice age, a much bigger, wider and deeper U shaped valley is left behind. * The original river now looks too small and out of place, so is called a Misfit river.

Glaciation Flashcards

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