In Brief

Rising Sea Levels Threaten Over 13,000 Archaeological Sites in the US

A new study suggests that thousands of archaeological sites in the southeastern United States will be underwater by the end of the century.

Site incidence as it relates to potential loss from sea-level rise, grouped by elevation in meters above present mean sea level (Public Domain image)

Rising sea levels will lead to the loss of more than 13,000 historic and prehistoric archaeological sites across the southeastern United States by the end of the century, researchers have found. These include sites such as the Lincoln Memorial in Washington, DC, St. Augustine in Florida — considered by many to be the nation’s oldest city — many Native American settlements, and countless cemeteries. The study, recently published in PLOS ONE, analyzed data from the Digital Index of North American Archaeology (DINAA), an online database that collects archaeological and environmental data sets from a wide array of repositories, from JSTOR to the Digital Archaeological Record.

Focused on nine states along the Gulf and Atlantic coasts, the paper also notes that thousands of locations currently designated eligible for inclusion on the National Register of Historic Places (NRHP) are also threatened. And this destruction will likely happen by the end of the century, assuming that sea levels rise about one meter (or just over three feet), as many scientists have projected. According to the researchers, an increase of that height would leave 19,676 recorded archaeological sites submerged, and while some of these might still be studied underwater, others will not survive. These figures are low estimates, since survey coverage is currently incomplete, and sea levels might more rise depending on global climate change.

“These numbers increase substantially with each additional one meter rise in sea level, with more than 32,000 archaeological sites and more than 2,400 NRHP properties lost should a five meter rise occur,” the researchers write. “Many more unrecorded archaeological and historic sites will also be lost as large areas of the landscape are flooded.”

Archaeologists and society at large, they urge, should be focusing on plans to preserve these sites as best as possible, whether those solutions involve the excavation or even relocation of infrastructures. As the paper suggests, the White House or Lincoln Memorial could be moved to safer land, just as the the Egyptian government, working with UNESCO, moved the Abu Simbel temples to higher grounds in 1963 to make way for the Aswan Dam. Similarly, in 1999, the National Park Service moved North Carolina’s historic Cape Hatteras Lighthouse due to shoreline erosion. Other sites that cannot be removed could potentially be safeguarded by the construction of protective barriers around them.

Yet, as the researchers note, such solutions might put even more sites at risk. Construction projects, namely, could affect many existing as well as undocumented cultural landmarks — which are also threatened by increased development as more people who live along the coasts are forced to move.

“The displacement of millions of people due to rising seas will cause additional impacts where these populations resettle,” the researchers write. “Sea level rise will thus result in the loss of much of the record of human habitation of the coastal margin in the Southeast within the next one to two centuries, and the numbers indicate the magnitude of the impact on the archaeological record globally.”

The unfortunate reality is that we won’t be able to save every threatened cultural resource. Archaeologists, as the researchers urge, will have to evaluate sites individually to determine which ones to protect. Such a task requires much more data collection and the assiduous mapping of archaeological sites to build up resources such as DINAA.

“We call for consideration of the entirety of the coastal record as one data set, rather than on an individual case-by-case basis,” the researchers write. “Effective systems of management, including triage and mitigation, can only be developed when we have an accurate understanding of the cultural resources in an area, and where critical gaps in that knowledge exist.”

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