UMass Amherst Geoscientists to Assess Sand Resource Needs Along Massachusetts Coast

Pre-nourishment photo of Barnstable Long Beach
Post-nourishment photo of Barnstable Long Beach

AMHERST, Mass. ­– Geoscientists at the University of Massachusetts Amherst have received a $200,000 award from the federal Bureau of Ocean Energy Management (BOEM) to evaluate sand resource needs at 22 public beaches along the Massachusetts coast over the next two years, establishing baseline characteristics for the first time and providing the data needed for future restoration planning.

Assistant Professor Jon Woodruff at UMass Amherst and state geologist Stephen Mabee, with a team of students and technicians, will lead the three-part study that will include surface sampling, surveying beach profiles and taking deep core samples in “back barrier” marshes and coastal ponds behind dunes. The work will start in August at beaches from Cape Cod and the islands southward in both summer and winter. In the winter and summer of the second year, 2015, the focus will shift to points north of Cape Cod.

The beaches are in Cuttyhunk, Falmouth, Hull, Marshfield, Nahant, Nantucket, Newbury, Newburyport, Oak Bluffs, Plymouth, Revere, Rockport, Salisbury, Sandwich, Scituate, Westport and Winthrop.

The award is part of President Obama’s commitment to help coastal communities recover from Hurricane Sandy and promote resilient coastal systems, according to BOEM. Goals include conducting research that will assist coastal communities, restore habitat, increase knowledge of sand resources offshore and contribute to long-term coastal resilience planning efforts.

Woodruff says, “This is the first, necessary step toward coming up with a plan for dealing with some hard issues related to coastal erosion.” The public beaches included in this study were identified by the state’s Office of Coastal Zone Management (CZM) as beaches in “critical need of assessment,” he adds. Many have sensitive and important infrastructure behind them, such as roads, bridges,wastewater treatment plants and harbors.

“If beaches are unstable and eroding, we need to be ready and forward-thinking, and whenever possible have a plan in place for dealing with the problem. What beaches can we save and what beaches can’t we save? With any of those decisions we need to know their composition and how dynamic they are.”

The most successful “beach nourishment,” that is, adding sand brought in from offsite sources, such as offshore deposits, to an eroding beach, is achieved when grain size is matched as closely as possible from the off-shore borrow source to native beach sands, the geoscientist explains.

Woodruff and his team will use state-of-the-art techniques and a uniform protocol to collect 700 to 800 surface samples over the two-year study at the 22 beaches and will prepare about 140 beach elevation profiles, in different seasons. The researchers will use a special particle analyzer in his laboratory instead of a traditional sieve, allowing them to compile the most detailed grain-size statistics ever collected for these beaches.

Deep core samples from back barrier marshes and coastal ponds will allow them to assess how much sediment is lost to each beach’s system through storm overwash, when hurricanes push the beach back over its dunes. The cores also let scientists estimate how frequently these events have occurred over the past few thousand years.

As Mabee explains, “If you are going to invest in nourishing the beaches with offshore sand, it would be nice to know how long your investment will last. Dating storm deposits in cores will provide some sense of the frequency of these larger destructive storm events in the past.”

Woodruff says that because Massachusetts’ CZM has already consolidated available off-shore data, “we’re in a better position than most when it comes to knowing the sedimentary characteristics of our offshore resources. This new study dovetails nicely with that. For the first time onshore data will be collected and integrated with off-shore data sets and made available to towns, planners and the public.”

CZM’s director Bruce Carlisle says the agency “looks forward to working as a partner on this important project, advancing the characterization of public beaches along the Commonwealth’s coastline. This information will support the determination of the types and volumes of sediments needed for specific beach and dune system restoration and nourishment.”

Woodruff’s academic work includes a recent review paper on coastal flooding by storms and sea-level rise for the journal Nature, in which he and colleagues point out that “society must learn to live with a rapidly evolving shoreline that is increasingly prone to flooding from tropical cyclones.” He adds, “It’s very clear that rates of sea-level rise are increasing and will continue to do so along the East Coast. It would be prudent of us to prepare for a general increase in beach and shoreline erosion in response to this.”