Assateague Island is in constant motion. Influenced by wind, waves, tides, and currents, sand movement continually reshapes the island and its shores. These forces, combined with a gradually rising sea level, cause Assateague to move a few feet westward every year. Thousands of years of migration have forced the island to continually "roll over" itself.
North End Migration
Human development has altered the natural dynamics of Assateague's north end. In 1933 a hurricane separated Assateague Island from Ocean City. Stone jetties were built to keep the inlet from closing with sand. The north jetty trapped sand that would have come to Assateague, creating a beach wide enough for a new parking lot. Assateague's sand-starved north end then migrated west at an unusually fast rate; 35 feet per year from 1935 until recently (normal rate is 3 feet per year). Movement has slowed, but action is needed to prevent the north end from merging with the mainland much sooner that it would under natural conditions.
(Inscription under the photo in the center of the marker)
Old tree stumps may appear on the beach after storms—evidence that the present shoreline was once an ancient forest growing on the island's west side.
(Inscription over the photo on the right side of the marker)
How Islands "Roll Over"
Many barrier islands retreat from the rising sea level through a natural process called overwash. During the most severe storms, powerful waves break over (overwash) and dissolve primary dunes. Successive waves flood the island, spreading sand over the wide areas. Sand often washes directly into the bay.
Dune, thicket, and marsh areas may be temporarily buried. After several overwashes, island movement is often visible; the marsh has grown into the bay on new sand deposits, and other island communities have shifted slightly west of their former locations.