Morris Island, SC
Though it is not in North Carolina, Morris Island, SC displays the processes that apply to the coastal plane of the southeast which have been discussed in previous sections. This case study reveals the effect of the east coasts’s passive margin which creates a long and gentle slope, wide continental shelf and fine grained sand. The YouTube video above shows just how flat this coastline is, which is very different from what you would see on the Pacific coast. Pair this with the southeastern coastal plane’s tendency to be prone to sea level rise, and you get a very dynamic and unstable shoreline. This became a problem only once humans started building houses and infrastructure along the coastline, as was the case with the Morris Island Lighthouse. The Morris Island Lighthouse was built in 1876 as a replacement for the original which was destroyed in the Civil War. At the time it was built, the new Lighthouse was built around 1,200-1,300 feet inland, but by 1948 it was just about touching the water. This is an astounding example of just how fast a shoreline can retreat due to rising sea levels and a flat coast. In 1962 the Lighthouse was officially abandoned and replaced by the new Sullivan’s Island Lighthouse, however the old one was never dismantled and still stands today, although it is owned privately now. Nevertheless, its strong and deep foundation and two phases of preservation have allowed it to stay in tact even as the shoreline continues to move farther away from it to this day.
Below are four images of the Lighthouse on GoogleEarth from 1989, 1999, 2010, and 2020. As you can see, the overall distance from the shore continues to increase steadily, although there have been some minor fluctuations along the way.
You may also note how from 1989 to 2020, the Morris Island shoreline went from jagged and pointy to more smooth and squared off. This is another example of how shorelines like to straighten themselves out over time due to the erosion and laying down of sand from ocean waves.
Works consulted: Pilkey (1998); SaveTheLight.org (http://savethelight.org/briefhistory.html)