What are the 4 agents of abrasion?

Moving water, gravity, air, and ice

• Gravity causes a rock tumbles down a mountainside or cliff.

• Moving water causes the particles in the water to collide and bump against one another.

• Strong winds carrying pieces of sand can sandblast surfaces.

• Ice in glaciers carries many bits and pieces of rock.

• Rocks embedded at the bottom of the glacier scrape against the rocks below.