Which structure is typically used as a form of coastal defense against wave action?

The structure typically used as a form of coastal defense against wave action is a sea wall. Sea walls are constructed along coastlines to protect the land and infrastructure from the erosive forces of waves. They absorb and reflect the energy of incoming waves, helping to prevent flooding and erosion of the coastline behind them. Sea walls can be made from various materials, including concrete and stone, and often have a curved or angled design to effectively redirect wave energy.

While breakwaters, jetties, and groins also serve important functions in coastal management, they do so in different ways. Breakwaters are built offshore to create calm water zones that reduce wave impact on the coast. Jetties are structures built to protect harbors or river mouths from sediment buildup and to control water flow, while groins are constructed perpendicular to the shoreline to trap sand and prevent beach erosion. Each of these structures plays a role in managing coastal systems, but the primary function of sea walls specifically addresses the direct threat of wave action to the land.