Spilling (front wave edge is ‘too steep’, water falls down) and Plunging (wave crest is ‘too fast’ and falls off the front, creating pipes)
Waves coming near shore at some angle are bent (or ‘refracted’) toward the shore.
Shoaling/refraction vs. wavelength
Larger effects on longer period waves (larger swing from fast to slow, all waves same speed at low depth)
Water parcels pushed along in front of wave (‘surf’ the wave), pile water onshore much like storm surge
Storm surge circulation goes out at depth, where more sediment is concentrated. This caries out sediment to the edge of the surf zone (sand bar formation, positive feedback)
Waves alone (with no currents) tend to sweep sand onshore. The water moves fastest at the crests (onshore direction) and sand motion is sensitive to velocity (higher velocity has proportionally higher effects).
Storm Erosion Cycle
During surge, sand is carried out due to pressure gradient. After storm, waves alone are acting on the sand and the beach is rebuilt (finds equilibrium with gravity)…
One area along beach loses wave power, water rushes out.
This often forms rip channel in the sand, perpetuating the effects