Rising Seas and Sinking Land
Nathaniel Batts may have been a recluse when he died in 1679, but he was a virtuoso wheeler-dealer in his younger days as fur trader, land owner, pardoned murderer, serial debtor, swindler, explorer who discovered an inlet, and friend of people in high places. (A prenuptial agreement forbade him to use his wife’s fortune to satisfy his debts; he found forgiveness elsewhere.)
Batt’s colorful life surely deserves a ten-part mini-series, but for now we are more interested in his grave as an expression of what has been lost to rising seas and sinking land.
The North Carolina Gazetteer says that in 1749 the island called Batts Grave was 40 acres in area and had houses and orchards on it; by 1756 it had been reduced to 27 acres.
By mid-twentieth century Batts Grave was reduced to a fly-speck on a map. Today it is gone.
Rising seas, hurricanes and nor’easters ate at the island. Sinking land played a small but inexorable role that continues today and makes the Albemarle even more vulnerable. Below is a map showing the big picture.
Blame glaciers for sinking, or subsidence. Tons of ice crush the land beneath. In response, unglaciated land south of the glacier eases upward. (Like a slow-motion see saw.)
As glaciers melt, compressed land begins to rise. Land to the south reacts by sinking. Now there are puddles and flooded streets after storms, worrisome to anyone living in a vintage family home where water now encroaches on the front porch.
Worrisome as it may be, this is only a micro-snapshot in time.
Let’s puts some boots on and rest for a moment at the edge of a melting glacier, say 15,000 years ago. Seas then are about 400 feet below today’s seas. A barrier beach might have been some fifty miles east of today’s Outer Banks.
The land is tundra-like, but warmer than you might expect because of the Gulf Stream that slides along the periphery. As climate warms, lush marshes and swamps will grow up, wonderful habitat for ice age mammals and birds — and early man.
As the earth warms and sea level rises, the shore line is pushed westward. Marshes are flooded and die and are born anew, replacing swamp forests whose trees have drowned but scattered seeds that will take hold on dryer land. It is an inexorable migration of life.
How far out on the continental shelf did early man live? The Albemarle area holds a plethora of fluted points and artifacts, including a dugout canoe from about 6000 BP (Before Present). The artifacts of those first Paleo-Indians, however, are drowned in open seas today, so we can only imagine the extent of their occupation..
These early Indians were hunter-gatherers who followed the food supply. They did not have vested interests in real estate and infrastructure, so they managed migration with skill. They accepted what the land had to offer, and moved on when necessary. You could say they were resilient.
It wasn’t necessarily an easy ride. There were great storms and droughts, and floods and freezes and forest fires, even a mini-ice age that lasted almost 1500 years.
Fossils of plants and animals and micro fossils of pollen tell stories. By analyzing and carbon dating the kinds of life found in core samples of strata, scientists can read the ancient waves of climate change.
Coring on Roanoke Island by the NC Coastal Geology Cooperative reveals a combined rate of subsidence and rise in sea level as follows: 3 inches prior to the 19th century; 7 inches by the end of the 19th century; 16 inches by the end of the 20th century.
Sounds impossible, doesn’t it, but remember Batts Grave. Our own casual observations of water levels on our bulkhead tell the same story: about 6 to 8 inches rise in thirty-five years.
Albemarle lands are among the most threatened in the country by a combination of subsidence and rising seas.
Would you like to go back to the past and see a piece of the future?
Take a minute to study the map above. The gray area represents an abrupt 20 to 25 foot rise from the lowlands of the coastal plain. It is called the Suffolk Scarp, or Suffolk Shoreline, and is apparent today on the west shore of the Chowan River.
The Suffolk Scarp is the remains of a shoreline that existed 80,000 to 125,000 years ago during a warm period when sea level was 25 feet higher than it is today.
At that time the Albemarle area was below water, a shallow continental shelf. The barrier islands that we know today did not exist.
Rising seas are expected to reach the Suffolk Scarp in the next 100 to 500 years.
What Do We Do?
Where scientists could not persuade, hurricanes, flooding, loss of low areas and the appearance of ghost forests are turning skeptics into believers in sea level rise.
How will communities respond to threats to their way of life?
We are beginning to realize that we can no longer do battle with rising water and storms. Past knee-jerk reaction has been to harden structures — create seawalls, build jetties, erect bulkheads, pile on the rocks, or the sandbags — to keep that water in its place.
Such efforts cannot be maintained in a dynamic environment where change is coin of a watery realm. Water will always win.
Tuning in to the natural world, and working with it, is the best way to preserve our well-being.
All that we have done to the land — ditching, draining, clear cutting the magnificent forests, building dams, laying down pavement — all this speeds up and re-routes the natural flow of water and makes the land — and its people — more vulnerable to the forces of climate.
Spongy wetlands allow water to seep ever so slowly through the landscape. Mighty trees in acres of forests have vast networks of roots that drink copious quantities of water. Once removed, there is erosion and puddles and muck. Ugliness, too.
New ideas must bubble up through collaboration with scientists, government officials and communities. Money is needed to experiment and implement. Like paleo-Indians we need to develop resilience, a concept that has been adopted by many planners.
Resilience to storms: Are we just mopping up after storms, or are we making decisions that will reduce future damage?
Communities need technical and financial assistance in planning, developing shovel-ready projects that can put fixes in place immediately after a government call for proposals. We should be working with climate, not against it, treating land as an asset to be managed wisely.
Resilience to rising sea level. Close kin of resilience to storms. We need to accept that we can’t prevent sea level rise, but we can develop long-term strategies tailored to sites and community needs.
Some examples that emphasize natural solutions:
- moving homes to higher ground
- planting trees whose roots are efficient at absorbing water
- removing impervious pavement
- removing ditches to promote more natural flow of water
- making the ground more spongy so rainwater percolates
The mills of government grind slowly. Rising seas care not.
As we already know, it is up to people brainstorming and barnstorming to find solutions that will protect the environment and take care of human needs.
With political will and public-private partnerships, the dedication of non-profit groups and a broad base of support from communities, we can tackle the tasks before us and make sensible plans that will take us into the future.
We can’t know all the answers because we can’t predict the curve balls to come, but with close observation, a thoughtful approach, and cooperative efforts we can develop the resilience that grounded those Paleo-Indians long long ago.
We thank the many career professionals and dedicated volunteers who are helping to protect the Sound, its land and rivers, and its wildlife.
I consulted many on-line sources to frame this Voyage through Centuries: in particular, historian David Cecelski whose blog with its wonderful old photographs gives insights to fisheries and everyday life; coastal and marine geologist Stan’s Riggs who tirelessly advocates for a realistic understanding of coastal dynamics and the opportunities they present; and Todd Miller, who founded The NC Coastal Federation, a powerful watcher of coastal land and water issues and publisher of Coastal Review Online.
This Voyage grew exponentially out of a grant the Albemarle Environmental Association received from the Albemarle-Pamlico Estuarine Study thirty years ago to produce a series of Profiles of Albemarle Sound and its rivers. The original versions can be found on the website AEA on the Web.