Those features are often observed on the beach after storms. A beach cliff is also called a scarp. Scarps are vertical cliffs, usually a couple of inches to a couple of feet high, near the water's edge formed by wave erosion during storms or heavy surf. Storms can cause extensive beach and dune erosion, which results in scarping of the dunes and narrowing of the beach.
The scarp is a the residual effect of storm wave attack on beaches. During a storm with high energy waves and higher than normal tide levels, sand is eroded from the beach and deposited in an offshore bar. The return of normal low energy wave conditions eventually moves this sand back onto the beach. Although the beach usually regains its pre-storm shape, some of the sand eroded by storm waves may be lost from the beach system to overwash deposits, the offshore zone, inlets, or spits.
