Final answer:
The main sources of sediment at the coast are tides, rivers, waves, and glaciers. Tides erode rocks and cliffs, rivers deposit sediment, waves transport sediment, and glaciers deposit sediment as they melt.
Step-by-step explanation:
The main sources of sediment at the coast are tides, rivers, waves, and glaciers. Tides contribute to sediment at the coast through erosion, as the movement of water during high tide can erode rocks and cliffs. Rivers play a role in deposition, as they transport sediment and deposit it at the coast when the water slows down. Waves are responsible for the transportation of sediment along the coast, as their energy causes sediment to move in a zigzag pattern. Glaciers contribute to sedimentation at the coast by depositing sediment as they melt.