1. Plucking: Imagine a glacier like a giant ice cube with rocks embedded within it. As the glacier moves over the land, it melts slightly at the base. This meltwater seeps into cracks and joints in the bedrock. When the water refreezes, it expands and exerts pressure, breaking off pieces of rock. These broken pieces become embedded in the ice and are transported away by the glacier. This process is called plucking.
2. Abrasion: As the glacier moves, the rocks embedded in its base act like sandpaper, grinding and scraping against the bedrock. This process, called abrasion, smooths and polishes the rock surface, creating striations (scratches) and grooves. The size and depth of these features can indicate the direction and power of the glacier's movement.
These two processes, plucking and abrasion, are responsible for shaping many of the dramatic landscapes we see in mountainous areas, like valleys, cirques, and U-shaped valleys.
