Mountains to the Sea
Appalachians
When viewing the southeast coast of the U.S. from space, or sailing off its shores as I often have, one sees the most magical symmetry in its shoreline. Starting from the north in North Carolina and travelling south for 400 miles to the middle of South Carolina are four Capes jutting into the Atlantic Ocean. The Capes are about 100 miles apart and joined by three long, shallowly concave, identically curved bays. The Capes are from north to south: Hatteras, the stormiest of the lot where the north moving Gulf Stream encounters the south moving Labrador Current, Cape Lookout with a beautiful lagoon ideal for a cruising sailboat looking for a restful anchorage, Cape Fear guarded by fearsome Frying Pan Shoals, and finally Cape Romain, a National Wildlife Refuge just north of Charleston, most of which is accessible only by boat.
Leaving the Carolinas and travelling further south, one comes to the Florida Plateau and the uncommonly flat State barely above sea level which sits upon it. No landforms here, one thinks, to break the mile after mile of uniform flatness. But leave the north shore of Lake Okeechobee, the huge shallow lake in the State's center, and drive Route 70 West. Out about 20 miles and covering less than one-quarter mile of highway, the road rises 120 feet and levels again. Of little note for one travelling in air-conditioned comfort at 60 mph with barely an increase in pressure on the accelerator, you have now ascended Lake Wales Ridge. Lake Wales Ridge is the oldest of Florida's relic beach dune ridges and forms the "spine" of peninsular Florida north/south for 116 miles.
Atop the ridge and walking east on fine, white sugar sand through the low scrub vegetation of which over 100,000 acres have been protected, one comes to the ridge's escarpment. Not a massive stone buttress like one might expect out West, this landform dropping precipitously 90 feet to the citrus grove below is nonetheless impressive. And more so because viewed ahead further to the east is a second parallel ridge, the Avon Park Ridge, with a lower rise appearing to advance towards you like an incoming wave. Similar to a terminal moraine in glacier country to the north with its recessional moraines deposited as the ice retreated, so it is with Florida's beach dune ridges with secondary/recessional dunes laid down eastward as the Atlantic Ocean receded. Interestingly, Lake Wales Ridge's western edge is not nearly as dramatic as its east because the Atlantic Ocean creates a high-energy coast compared to the low-energy coast on Florida's west side where it meets the Gulf of Mexico. And the fine, white sugar sand, deep, loose and dry, sorted by wind and wave and carried for 400 miles, identifies the ridge as an ancient beach dune due to its lack of organic material or clay which would have added color.
There is a natural phenomenon which unifies these two landforms: the sculpted bays and capes of the SE Atlantic coast and the impressive beach dune ridges running down Florida's center. Its secret is given away by the flocks of seabirds which annually raft near shore in the Atlantic swells. These birds prefer the calmer seas just south of the Capes, and here is the clue - they congregate in the lee or directly downwind of them. For millennia the winds that have prevailed on earth at the location of Florida and the southern Capes is northeast. This wind coming from that direction has driven sea and sediment and relentlessly sculpted both the shoreline and laid up the sand dunes in its path further south.
These two landforms, different in shape and locale, were yet designed by the same forces. Both the Carolinas' coastal beaches and Florida's inland dunes were carried south by wind and wave, churned and cleaned, as the ancient, mighty Appalachian Mountains eroded slowly into the sea.
