Our national parks contain diverse coastal environments: high-energy rocky shorelines of Acadia National Park in Maine, quiet lagoons within War in the Pacific National Historical Park in Guam, and the white sandy beaches of Gulf Islands National Seashore in Mississippi and Florida.
In general, the coastal environment can be defined as that area lying at the interface between land and Oceans (or other large body of water). It includes both the zone of shallow water within which waves are able to move sediment, and the area landward of this zone, including beaches, cliffs, and coastal dunes, which is affected to some degree by the direct or indirect effects of waves, tides, and currents. The coastal environment itself may extend inland for many miles.
A variety of factors—including wave energy, tidal range, sediment supply, beach materials, continental-shelf slope and width, and past geologic history (e.g., glaciation, volcanism, and plate movement)—characterize coastal environments.
The coastal zone is one of the most dynamic regions on earth. Think of it, 70% of our planet is covered in water possessing enormous energy!
Coastal processes create many erosional or depositional features we see when visiting the National Parks such as:
Beach ridges are wave deposited sand ridges running parallel to shoreline.
A wave-cut scarp is a steep bank created by wave erosion.
A marine terrace is a raised beach or 'perched coastline' that has been raised out of the reach of wave activity.
Coastal Landform Types
Over time, the interaction of coastal processes and an area's geologic setting leads to the development of characteristic and dramatic coastal landforms. See the articles below for an introduction to some of the coastal landforms present in parks: