The Norton Point Beach breach may close as early as this year, an event that would bring to an end a dramatic, five-year phenomenon that has eaten away large chunks of the southeastern corner of Chappaquiddick, according to a top regional expert in coastal erosion.
Gregory A. Berman, of the Woods Hole Sea Grant program and Cape Cod Cooperative Extension, made a site visit Thursday morning to Wasque at the eastern tip of Norton Point Beach. He said he was struck by how much the breach has migrated to the east and narrowed. Mr. Berman estimates the breach is only 200 feet wide, or half the width of the Chappaquiddick and Memorial Wharf ferry channel at the opposite corner of Chappaquiddick Island.
“It will probably be a storm that will close it,” Mr. Berman said.
The breach, an opening that allows an exchange of seawater between Katama Bay and the open ocean, was created in April 2007 during the Patriots’ Day storm. At times it allows the water to move as swiftly as a river.
Acres of land bigger than football fields have been eroded away at Wasque during what the scientist calls a natural process, a repetitive event that takes place every couple of decades.
Based on what has happened in the past and what is happening now, Mr. Berman said the end is in sight. “As in the past, the breach migrates to the east until eventually it seals itself off,” he said.
Mr. Berman, a coastal processes specialist, spends a lot of his time looking at area beaches across the Cape and meeting with town officials to talk about the changes taking place. He is an expert in erosion and understanding how sand moves in water and on land. Thursday, he met with members of the West Tisbury conservation commission to talk about how they are managing moving sand at Lambert’s Cove Beach.
Wasque is one of the top beaches on the Cape and Islands, where change is going on quickly. Pleasant Bay in Chatham is also undergoing significant day-to-day changes. Coincidentally, the breach at Norton Point and at Pleasant Bay took place during the same storm, from April 15 through 17, 2007.
Mr. Berman, who has made a number of visits to the area, said the disappearance of so much land at Wasque is tied to the breach. There is a lot of water moving around the breach area. Fishermen love the spot because the currents meet off Wasque and form a rip, one of the most dramatic and most productive fishing spots in the region.
Normally, sand migrates on South Beach from west to east. When the breach occurred, it upset the natural migration of beach sand. “The breach robbed sand that would have gone to Wasque,” Mr. Berman said.
Prior to the breach, Wasque was being both eroded away and nourished by moving sand, Mr. Berman said. “Wasque was at a state of equilibrium. Sand was being deposited and eroded at the same time,” Mr. Berman said. “It looked a lot more stable than it was,” he said.
Troubles arose, Mr. Berman said, when sand stopped coming from the west.
Land creating Wasque--and for that matter all of Chappaquiddick--was deposited by the glaciers 20,000 to 23,000 years ago. Even if the breach ended, today, that land will not come back. “That is not coming back without another glacier,” Mr. Berman said. But what he said will happen is that sand dunes will come back, as they already are and being deposited against the older cliffs. The beach in front of the cliffs reveals parts of buried trees that have fallen in past storms. Where the beaches will stabilize is still not easy to predict until the breach closes.
Norton Point Beach is a barrier beach that measures 2 1/2 miles long and normally connects Chappaquiddick to Katama. At times during the last four years, the breach grew to as much as a quarter of a mile in width. Though the opening was close to the center of the beach when it began, it has since migrated to the east. At times the migration has been quick. Mr. Berman said the breach has moved as much as 1,000 feet and as little as 500 feet in a year. “It is striking how quickly the breach has marched eastward,” he said.
While this event has a history that goes back centuries, this particular breach is the best documented through the use of high-tech GPS and aerial photography. Mr. Berman brought his own GPS device to measure different sites along the changing beach. There is much to learn, Mr. Berman said, but it is also reassuring that the cycle is being repeated.
In another dramatic development, a 1,000-foot-long sandbar just offshore that runs along Norton Point Beach and Wasque is far more developed than it has been in the past. Mr. Berman said that sandbar is contributing to the healing process by protecting the fragile opening from continuous roar of big ocean waves.
Mr. Berman said the sandbar is being created by sand that might otherwise have migrated to Wasque. Should the breach close, sand will again resume migrating down the beach and end up at Wasque.
Separate from the current breach, rising sea level is causing all of the Island’s south-facing beeches to recede, Mr. Berman said.
The one impact that rising sea level will have on the area is that breaches at Norton Point may be more frequent in the future than they’ve been in the past, Mr. Berman said.
There is still plenty going on at Wasque while the breach appears to close. Sand continues to move and cliffs continue to be eroded. Last week, the stairs that made it easy for fishermen to access Wasque were about to succumb to moving water and beach.
Looking ahead, Mr. Berman said all it would take is a big storm with the winds coming from the right direction, and a “large slug of sand” to bring closure to the breach. “It could happen as early as this winter,” he said. It is not likely to happen in the summer, when the weather and the sea are more mild, he said.
No matter what, the area is incredibly dramatic and dynamic. It is conceivable that a new breach could form somewhere else along Norton Point Beach, Mr. Berman said. “When it comes to beaches,” he said, “storms can open or close them.”