Shifting Sands
Salt Marsh Diaries
By Anton Dumars
I idled into the cove behind the southwestern Morris Island spit. Right away, something wasn’t right. I’d spent a summer swimming, crabbing, and casting for bait in this cove. Nearly every day, I negotiated the narrow channel and avoided the shoals in this protected water body. Now, at dead high tide, my skeg bumped the bottom where the day before I had plenty of water.
An old chart, dated 1900, features a prominent spit on the southwestern end of Morris Island. In 1900, this spit existed 1600 yards seaward of its progeny. The past and present spit show uncanny resemblance in both size and orientation. After almost 100 years of retreat, Morris Island’s southwestern sand volume once again made muster. Natural wind and wave forces persisted, rendering a modern copy. Daily processes usually trump episodic events.
As I nosed the bow onto the shoreward side of the spit, my passengers jumped out to explore the island. Just down the beach, a lone fisherman sat in a lawn chair, watching his surf rod. Before we’d landed, I saw him release a big red drum back into the September surf. I set the anchor, noting a continuous overwash from the new-moon spring tide surf. Overwashing waves developed a channel, dividing the spit in two.
A steady sand slurry, directed through the channel, flowed hell-bent on filling the cove. My guests returned and boarded the boat through ankle-deep water. I started the motor, stowed the anchor, and began my retreat from what, only the day before, was a predictable exit. Bumping and lurching my way out of the cove at dead high tide had me wearing a nervous smile, the bottom now foreign like the dark side of the moon. I returned the next day, finding five acres of sand occupying the former cove.
A coastline, like one’s life, can experience months — even years — of relative stability. Then some random event takes the whole mess, shakes it up, and casts it back out, rendering our world unrecognizable. But, nature finds an average. Persistent daily forces once again take charge, sculpting life into a semblance of its previous exist
ence.
ABOUT THE PHOTO: This image compares shoreline of Morris Island in 2005, superimposed with shoreline in 1900. From Anton Dumars: “I did an erosion study for CCPRC in 2007, involving determining erosion rates for South West (SW) Morris and NE Folly. I traced shorelines back to 1858, overlayed them onto the 2005 shoreline. Next I calculated rate of shoreline movement, then graphed it. I actually got to use calculus to find the minima of the graph (1st derivative), which gave me the approximate year when erosion stopped on SW Morris. What you see is a trace of the 1900 shoreline (filled in with some transparency) overlying the 2005 shoreline. This way, you can see the similarity between two natural spits on Morris 105 years apart. Both spits are in their original location. Charleston Jetties were finished in 1895 and Morris Island started retreating soon afterwards. The 1900 spit is the last appearance until 2005. Once SW Morris Island started building up again, natural processes (which remain constant) finally had enough material available to build a replica spit. The looming question today is, ‘Where’s the sand coming from?’
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