What is the term for ice movement that wears down rock surfaces?

• A. Glacial erosion
• B. Volcanic eruptions
• C. Sedimentation
• D. Oceanic crust

Answer: (A)

Moving ice wears away rock through abrasion and plucking, a process called glacial erosion. As a glacier slides over bedrock, it carries along rocks embedded in the ice that grind against the surface, carving grooves, scratching striations, and smoothing or deepening valleys. This distinguishes it from other processes: volcanic eruptions involve molten rock and explosion rather than ice-driven wear; sedimentation is the laying down of eroded material; and oceanic crust refers to a part of Earth's lithosphere, not a process of rock wearing away. So the term for ice movement that wears down rock surfaces is glacial erosion.