III. C. 2. Cross-Shore Transport |
Breaking waves also move onshore and offshore. Fine sediment suspended in the water column is transported in the offshore-directed currents. Larger sediment particles that are mobilized by the combined shear stress of the wave and current are moved down-slope under the influence of gravity. High waves and storm-generated waves, which occur mostly in the winter, tend to move sediment offshore where it can/may be permanently removed from the coastal system. Figure III-13 shows the general sediment transport components.
Figure III-12. Spit, tidal delta, lagoon, and tide flat at Fletcher Bay (Source: Space Imaging, 2001).
Figure III-13 Sediment loss and supply on a coastal shoreline.
| <<iii.c.1. drift cells |