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.)

Section of a 1775 map showing Batts Grave south of today’s Yeopim River

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.

The Albemarle area today showing the coastal plain vulnerable to sea level rise, the old Suffolk Shoreline at 25 to 50 feet above sea level, and the Fall Line (in black) where the rolling hills of the Piedmont begin. NC Land of Water

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.

Tundra on the continental shelf miles off today’s shore line? As climate warms, marsh and swamp will develop over thousands of years, then migrate west as sea level rises. NOAA

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.

Photo of our boardwalk circa 1988. Note mini-dock we had for disembarking canoes and horizontal timber visible to the right. Today these  are totally submerged  except on rare occasions when the wind blows steady out of the north and water is pushed to the south. aheronsgarden.com

It’s not unusual for a storm to cause water to rise to the top of the bulkhead these days. After most storms some parts of our woodlands flood. aheronsgarden.com

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?

Where the sea has been and where it is going, Stan Riggs History of Sea Level Rise. NC Division of Coastal Mgmt.

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.

This photo by geologist Stan Riggs pictures a terrace that adjoins the Suffolk Scarp along the Chowan River which flows into western Albemarle Sound

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.

As sea level rises, salt water, from overwash of hurricanes, for instance, can kill plants that are not salt tolerant. These ghost forests are occurring on the Albemarle/Pamlico peninsula today. Mark Hibbs, South Wing SCRO

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.

Sand bags scattered on the barrier beach after a storm. Not working too well, judging from the flooding. NC Coastal Federation

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.

This former farm has been converted to wetlands. Rainfall once took only two minutes to drain into nearby waters. Now it takes more than two months. NC Coastal Federation

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?

Managing flood waters after Hurricane Matthew. Almost one and a half billion dollars has been spent to clean up after Matthew and Florence alone. Photo by Leticia Samuels, USCG

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.

Even small projects like planting a rain garden will help. NC Coastal Federation

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

Wide swales on the side of a road diffuse runoff of rainwater and sediment, further helped by woodlands that transpire moisture. On grand scale, this is a technique that would mitigate runoff from miles of impervious roads, driveways and parking lots. NC Dept of Transportation

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.

They will thank us. Photo of baby otters by Meekins USFWS

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.