What is a glacial trough in geography?

What is a glacial trough in geography?

Glacial troughs, or glaciated valleys, are long, U-shaped valleys that were carved out by glaciers that have since receded or disappeared. Troughs tend to have flat valley floors and steep, straight sides.

What is a glacial trough also called?

glacial valley, also called glacial trough, stream valley that has been glaciated, usually to a typical catenary, or U-shaped, cross section. U-shaped valleys occur in many parts of the world and are characteristic features of mountain glaciation.

What causes glacial troughs?

Glacial trough or U-shaped valley As glaciers move downhill they change V-shaped valleys into U-shaped valleys or glacial troughs . The ice has great erosive power and removes any obstacles such as interlocking spurs .

What is a glacial trough GCSE?

Glaciers cut distinctive U-shaped valleys with a flat floor and steep sides. The glacier widens, steepens, deepens and smoothes V-shaped river valleys, eg Great Langdale Valley in the Lake District.

How are glacial troughs formed a level?

The formation of a glacial trough involves two processes abrasion and plucking. Abrasion is when pieces of debris in the glacier wear away at the rocks below, a bit like sandpaper. The sharper rocks in the ice can also cause scratches in the rocks called striations.

What is the difference between AV shaped valley and a glacial trough?

Glacial erosion causes the formation of U-shaped valleys, whereas V-shaped valleys are the result of carving by the rivers through their course. U-shaped valley walls are straighter than V-shaped valleys due to the non-bending glacier’s movement.

What’s the meaning of ice sheet?

An ice sheet is a mass of glacial ice more than 50,000 square kilometers (19,000 square miles). Ice sheets contain about 99% of the freshwater on Earth, and are sometimes called continental glaciers.

What is plucking in geography?

Definition: Plucking is a process of erosion that occurs during glaciation. As ice and glaciers move, they scrape along the surrounding rock and pull away pieces of rock which causes erosion. Plucking.

What is a glacier GCSE geography?

As more snow falls, the snow is compressed and the air is squeezed out to become firn or neve . With the pressure of more layers of snow, the firn will, over thousands of years, become glacier ice. Erosion and weathering by abrasion, plucking and freeze-thaw action will gradually make the hollow bigger.

What do glacial striations tell about a glacier?

Glacier scientists often use striations to determine the direction that the glacier was flowing, and in places where the glacier flowed in different directions over time, they can tease out this complex flow history by looking at the layered striations.

What is crag and tail glacier?

A Crag and Tail consists of a large mass of resistant rock on the STOSS (upslope side) and a gently sloping tail (on the LEE side) of less resistant rock. This is a geological formation caused by the passage of a glacier over an area of hard rock and softer rock.

What are some examples of glacial valley?

Glaciers carve a set of distinctive, steep-walled, flat-bottomed valleys. U-shaped valleys, fjords, and hanging valleys are examples of the kinds of valleys glaciers can erode.

What is a glacial trough and how does it form?

Glacial troughs are also known as u-shaped valleys and form when a glacier erodes a v-shaped valley. Glacial troughs have flat bottoms and steep sides. Hanging valleys and ribbon lakes are features of glacial troughs. Intro Quiz Presentation Transcript Glaciation:

How are glacial valleys straightened?

They are formed in river valleys which, during the ice age, have been filled by a large glacier. These glaciers have deepened, straightened and widened the valley by plucking and abrasion. A hanging valley is a smaller side valley left ‘hanging’ above the main U-shaped valley formed by a tributary glacier.

What are glacial striations and glacial erratics?

To the modern geologists, an erratic refers to any sized chunk of rock that has been plucked from the bedrock and moved somewhere else by geologic forces (a glacial erratic refers, then, to rocks displaced by glaciers). These rocks vary in size from gargantuan to tiny (e.g. clay particles).

What are the characteristics of glacial soil?

– Test 100 mm dia. samples to determine the undrained shear strength for each sample. – Assess the fabric of each sample and determine whether this influenced the failure. If the fabrics are significant, disregard the results. – Group the results according to their liquidity index, water content, density and fabric to remove any outliers.