Question

What shape do glacier-created valleys have? A) V-shape C) U-shape B) L-shape D) S-shape

Short answer

C) U-shape.

Step-by-step solution

Identify the Nature of Options

The question provides four options regarding the shape of a glacier-created valley. These options are A) V-shape, C) U-shape, B) L-shape, and D) S-shape. We need to determine which one correctly corresponds to the typical formation by a glacier.

Understand Glacier Valley Formation

Glaciers carve through landscapes as they move very slowly over time, eroding the bedrock beneath them. This process typically forms a distinct type of valley known for its specific shape.

Recall Characteristic Glacier Valley Shape

The characteristic shape formed by glacier erosion is a U-shape. This is distinct from fluvial erosion, which typically forms V-shaped valleys.

Select the Correct Option

Given that glacier valleys are U-shaped due to the erosive force of the glacier's movement, we select option C) U-shape as the correct answer.

Key concepts

U-shaped valleys

U-shaped valleys, also known as glacial troughs, are one of the most striking landforms created by glacial movement. When a glacier moves through a valley, it acts like a slow-moving, colossal ice plow, carving out a wide and deep valley in the landscape. The process flattens the bottom and steepens the walls, giving it the characteristic U-shape as opposed to the sharp and narrow V-shape created by rivers.

Key features of U-shaped valleys include:

• Wide valley floors, contrasting the narrow teardrop shape of river valleys.
• Steep, straight, parallel walls.
• Smooth valley bottoms due to glacial scouring.

U-shaped valleys can often be seen in mountainous regions where glaciers have retreated, leaving behind these distinct landforms.

glacier erosion

Glacier erosion is a powerful and dynamic geological process. Glaciers, unlike rivers, move extremely slowly across the land, carrying with them vast amounts of debris, rocks, and sediment. As these ice giants progress, they use two primary mechanisms to erode the landscape: plucking and abrasion.

**Plucking** occurs when meltwater at the glacier's base freezes around rocks. As the glacier flows, it "plucks" these rocks away, dislodging them from the ground.

In **abrasion**, rocks and debris embedded in the ice act like a giant sheet of sandpaper, grinding and polishing the surface below as the glacier moves.

• Leaves scratches and grooves known as striations on bedrock.
• Produces fine material called "rock flour," giving a milky appearance to meltwater streams.

Through these processes, glaciers dramatically reshape the topography, forming unique landscapes.

glacial landscape formation

Glacial landscapes are marked by a series of distinctive features formed by the various activities of glaciers over millennia. When the ice advances, it sculpts the terrain into dramatic and varied landforms.

Some key landforms include:

• **Cirques**: Bowl-shaped hollows where glaciers originate, often forming stunning natural amphitheaters.
• **Arêtes**: Sharp ridges carved by glaciers on either side, providing an unmistakable silhouette in mountainous areas.
• **Horns**: Pyramid-shaped peaks formed when several cirques erode a mountain from different sides.
• **Moraines**: Accumulations of glacial debris at the edges or terminus of glaciers. They can indicate the furthest advance of the glacier.

The complex interplay between glacial movement, ice melting, and debris transport leads to the rich diversity of these features. Together, they shape the awe-inspiring landscapes that draw so many admirers and researchers to study the ancient paths of ice.