glacial scour

Glacial scour is the process by which glaciers erode the land beneath them. This occurs through two main mechanisms: abrasion and plucking. Abrasion happens when rocks and debris embedded in the glacier's base grind against the bedrock, creating scratches and grooves called striations. Plucking involves the glacier freezing onto bedrock and pulling away larger chunks of rock.12

Temperate glaciers, which are at the melting point, are more effective at erosion due to basal sliding. Cold-based glaciers erode less effectively because their ice is frozen to the bed, limiting sliding and abrasion. Glacial scour has shaped many landscapes, creating features like deep valleys, fjords, and lake basins, particularly in areas once covered by large continental ice sheets.134