Effects of breaking waves
Breaking waves often have foamy or aerated water
When bubbles or cavities collapse, water moves rapidly across cavity & generates locally very high pressure
Collapsing cavities & bubbles blast the substrate to bits
Breaking wave & its backwash move water with rock detritus, & so abrade the substrate
Effects of breaking waves concentrated in narrow range of depths, creating a wave-cut terrace
At landward end of terrace, may have notch in sea cliff; erode of sea cliff by undercutting & collapse of cliff
Debris, both large & small, on beach, is rounded