Before and After: Cape Hatteras

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Lush forest land turns to dead brown foliage. The north polar ice cap recedes. Text, Before and After. Cape Hatteras, North Carolina.

 

The Earth rotates in space. Thousands of kilometers of Earth's coastlines are protected from the ocean by narrow strips of sand and mud known as barrier islands. One of the longest barrier island chains in the U.S. is the Outer Banks, located off the coast of Virginia and North Carolina. Like other barrier islands, the Outer Banks are continuously transformed by wind, waves, tides, and currents. Outer Banks, North Carolina are pointed out on the east coast of the U.S.

 

Outer Banks, North Carolina, July 7, 2015. Operational Land Imager, Landsat 8. An aerial view of a long strip of sand blocking the mainland from the greater ocean. One of the most dynamic points is Cape Hatteras, which is shaped by the convergence of several ocean currents, as well as daily tides and occasional storms. Cape Hatteras is a nearly 90 degree kink in the island chain. Shoals --shallow ridges or sandbars --are common offshore in this region, and have caused many shipwrecks. Zooming in to Cape Hatteras, North Carolina. November 16, 2016. Like the beaches, these shoals are constantly shifting. Although they are usually under water, parts occasionally rise above the surface. This image, captured by the Landsat 8 satellite, shows the submerged shoal area off Cape Point, the tip of Cape Hatteras, in late 2016. January 28, 2017. Breaking waves. By early 2017, the shoal had begun to grow visibly toward the ocean surface. Though still under water at the time, the sandbar was shallow enough for waves to break against it. July 7, 2017. Shelley Island. By the middle of 2017, the shoal --now known as "Shelley Island" --had broken the surface and was clearly visible from space. Other smaller shoals farther out also now break the waves. Scientists are not certain exactly why the shoal grew over this time. One likely possibility is that the sand that caused the shoal to grow originated in the barrier islands further north. A combination of winds and currents may have transported the sand southward and then deposited it at Cape Point.

 

February 16, 2018. Shelley Island quickly transformed as waves and currents further redistributed the sand. It's now merged with Cape Point. By early 2018, Shelley Island had all but disappeared.

 

The four images are shown side by side to compare the change over time. In the future, wind and water will continue to move the sand that makes up the barrier islands of North Carolina's Outer Banks, slowly and continuously transforming the coast.