shoreface

The shoreface is the part of a coastline that lies seaward of the shoreline and is actively reshaped by waves and currents. It extends from the shore toward the continental shelf, including the foreshore and the subtidal zone, until wave energy and sediment transport decline toward deeper water. The exact seaward limit varies with coastal setting and is commonly associated with the depth of closure, a depth at which significant offshore transport becomes negligible. This depth can range from only a few meters to several tens of meters depending on wave climate and coastal slope.

The shoreface experiences strong cross-shore sediment transport driven by breaking waves and undertow, as well as alongshore transport by longshore currents. The inland boundary with dunes and berms marks the subaerial portion of the coast, while the shoreface proper hosts features such as sandbars, ridges, and troughs that migrate in response to changing seas. Sediment supply, storm events, and human modifications influence its morphology and stability.

Importance and uses: understanding the shoreface is essential for coastal engineering, sediment budgets, and paleogeography. It records past wave climates and governs how coastlines respond to sea-level rise, storms, and nourishment projects. Observations are obtained through bathymetric surveys, seismic profiling, and sediment cores, which together help characterize its dynamics and evolution.