Glaciers scraping rocks across the surface is a process called glacial erosion. It's a powerful force that shapes the landscape in many parts of the world. Here's what it means in more detail:

* Glaciers are massive sheets of ice: They move slowly over land, carrying rocks and debris embedded within them.

* The embedded rocks act like sandpaper: As the glacier slides, these rocks grind against the bedrock beneath, causing abrasion and wearing away the surface.

* This process creates distinctive features: The result of glacial erosion includes:

* U-shaped valleys: Glaciers carve out deeper, wider valleys than rivers, creating the characteristic U-shape.

* Cirques: Bowl-shaped depressions formed at the head of glaciers.

* Fjords: Deep, narrow inlets formed by glaciers carving out valleys that were then flooded by the sea.

* Striations: Scratches and grooves etched into the bedrock by the embedded rocks.

* Till: Unsorted rock debris deposited by glaciers, often forming moraines (ridges of sediment).

In essence, glaciers scraping rocks across the surface is a powerful form of erosion that shapes landscapes, leaving behind distinctive features that tell the story of past glaciation.