Baja
California, Mexico
High wave energy erodes the headlands projecting into the Pacific Ocean,
while sandy pocket beaches form in protected bays.
A wave-cut notch is formed at the end of this headland. The notch is at the elevation of high tide waves; the photo illustrates low tide.
The Pacific Coast of California is often characterized by steep bluffs and small pocket beaches.
Jagged rocky headlands and small pocket beaches are typical of sediment-poor coasts.
The irregular Pacific coast.
A sea arch along the Pacific coast.
The Delaware coast is an emergent, sediment-rich coast with broad beaches.
In the surf zone, waves and beach swash move water and substantial sediment. Note the suspended sand at the water’s edge.
Waves often approach the shore at an angle, as shown here, creating the longshore current which moves large quantities of sediment parallel to the shore. Note slumping of sediment down the eroding bluff, as shown by the blocks of sumac and sod that once grew at the top of the bluff.
Aerial view of wave fronts approaching the Lake Michigan shoreline at an angle. Longshore current is left-to-right across the photo.
Waves swash up the beach at an angle and backwash flows back to the sea perpendicular to the shoreline. This sets up the “beach drift,” a movement of sediment along the beach that is a significant component of longshore drift.
A set of groins protect the Lake Michigan shoreline in the background. Notice that in the area of the groins the bluff is stable, as indicated by a less steep slope and mature forest. In the unprotected foreground, the shoreline is eroded and the bluff is steep, unvegetated, and unstable.
A concrete and timber groin built to protect the beach from erosion by the longshore drift.
Notice that sand has accumulated up-current of the groin (left of photo), while the beach is eroded and lower down-current of the groin (right of photo).
Aerial view of the barrier island "Juist" in the North Sea, just off the coast of northern Germany. Notice the broad sand beach and the sand dunes typical of barrier islands. Some stick fences have been installed to stabilize the dunes.
Juist,
northern Germany
Another aerial view of the barrier island Juist. Such islands are long,
narrow, and dynamic, with sand constantly being eroded and deposited.
Topographic map of a barrier island on the New Jersey coast. Note the characteristic narrow, linear form.
Topographic map of a submergent, sediment-poor coastline. Notice the irregular coastline and lack of beaches.
Topographic map of a spit.
Topographic map of bay mouth bar.
