Rising seas threaten thousands of world cultural sites | Science News for Students

Rising seas threaten thousands of world cultural sites

How we can preserve our archeological heritage in the face of rising seas
Jan 10, 2019 — 6:25 am EST
a photo of huge stone statue figures at Rapa Nui, or Easter Island

These huge stone statues are at Rapa Nui, or Easter Island. This Chilean island lies 3,500 kilometers (almost 2,200 miles) west of the mainland, deep in the Pacific Ocean. The island is one of many places worldwide that are vulnerable to sea-level rise.

Babak Fakhamzadeh/Flickr (CC BY-NC 2.0)

Sea level is rising. This threatens the future of millions of people around the world. It also threatens our cultural past.  

“It’s really the history of our species that’s at risk in a lot of ways,” says Meghan Howey. She’s an archaeologist at the University of New Hampshire in Durham. Humans have lived near the coast for thousands of years. In that time, they created and left behind many cultural sites that hold pieces of the past. These are famous places such as Rapa Nui (Easter Island) in the central Pacific Ocean and the canal city of Venice in Italy. But they also include many smaller and lesser known sites. They range from Native American villages to early colonial settlements. If rising seas destroy these sites, “we’re going to lose [those people’s] stories too,” Howey says.

a map showing locations of archaelogical sites on the southeastern coast of the United States endangered by rising sea waters
A rise of one meter (39 inches) in sea level threatens more than 13,000 U.S. archeological sites in the Southeast alone, according to one 2017 report.
D.G. Anderson et al/PLOS ONE 2017

David Anderson is an archaeologist at the University of Tennessee in Knoxville. “If you want to learn about what people did in the past, archaeology is the best way to do that,” he says.

Anderson and other researchers recently used online data sets to look at the dangers posed by rising seas to cultural sites in the southeastern United States. A one-meter (39-inch) rise in sea level could destroy more than 13,000 of those places, they found. These include some well-known historical sites found in Jamestown in Virginia, St. Augustine in Florida, and Charleston, S.C. Many Native American sites also are at risk. The team’s November 2017 report appeared in PLOS One.

That study looked at just one region. But elsewhere around the world, countless other sites also face risks from climate’s impact on sea level.

Howey did a similar count in New Hampshire. Up to 14 percent of the state’s heritage sites could be lost to sea level rise, she found. Studies have also found similar risks — in the range of 15 to 20 percent — globally, she notes. “And that’s only what we know about,” she adds.  

What now?

Climate change is underway. So now is the time to start thinking about sea-level rise, Anderson says. “How are we going to protect the important places in the landscape? We need to know what’s out there and what’s threatened.” Otherwise, it may become too late to save at least some of these sites.

Digital scanning technologies can preserve images of imperiled sites for people around the world to see. This image shows the contours of a giant statue on Rapa Nui, or Easter Island
Digital scanning technologies can preserve images of imperiled sites for people around the world to see. This image shows the contours of a giant statue on Rapa Nui, or Easter Island.    

Efforts to limit the worst impacts from climate change, including sea level rise, will require cutting greenhouse-gas emissions, for example. And maybe taking steps to limit flooding in important areas.

Another approach might be to move cultural treasures. But projects like that are often costly. It’s unlikely that funds to do that will be available for every site. And some treasures simply can’t be moved.

But high-tech tools might help preserve knowledge of those treasures before physical sites are lost, says Mark McCoy. He’s an archaeologist at Southern Methodist University in Dallas, Texas. He recently suggested how this might be done at many sites in Polynesia. That’s an area composed of many Pacific low-lying islands.

Rising seas endanger many of those islands — and their cultural treasures. If researchers used only traditional methods to map those places, “most would be gone before you got to them,” he says. Satellites with cameras and other remote-sensing tools, however, can more quickly and easily find and map many of these sites, he says. Those data can also help researchers assess the risks to particular spots.

Scanning and imaging tools can help, McCoy explains. For example, LIDAR is a type of system that uses lasers to make precise 3-D scans of objects. High-resolution digital photography can make detailed images. Computer technologies also can create 3-D virtual reality models. They may not save cultural sites, but they could preserve at least some knowledge about them for the future. His report appeared in the January 2018 issue of Sustainability.

Rising seas are likely to eventually bury a lot of archaeological treasures. And in some cases, the old techniques that archaeologists have long employed also may help. “I still use traditional methods out on a site when the conditions call for it,” McCoy notes. For instance, he notes, “Paper and pencil do not require batteries and don't break when I drop them on rocks.”

See how CyArk preserves information about archaeological sites with digital technology.
Seagate Technology/YouTube

Power Words

(more about Power Words)

3-D     Short for three-dimensional. This term is an adjective for something that has features that can be described in three dimensions — height, width and length. 

archaeology     (also archeology) The study of human history and prehistory through the excavation of sites and the analysis of artifacts and other physical remains. Those remains can range from housing materials and cooking vessels to clothing and footprints. People who work in this field are known as archaeologists.

climate     The weather conditions that typically exist in one area, in general, or over a long period.

climate change     Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.

colonial     Geographical: An area under full or partial control of another country, typically far away. Biological: Organisms that live as part of a structured and organized community.

data set     A large, discrete group of data collected or assembled for a particular purpose.

digital     (in computer science and engineering)  An adjective indicating that something has been developed numerically on a computer or on some other electronic device, based on a binary system (where all numbers are displayed using a series of only zeros and ones).

greenhouse gas    A gas that contributes to the greenhouse effect by absorbing heat. Carbon dioxide is one example of a greenhouse gas.

laser     A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, in data storage and in surgery.

lidar     (short for light detection and ranging) A tool to measure the shape and contour of the ground from the air. It bounces a laser pulse off a target and then measures the time (and distance) each pulse traveled. Those measurements reveal the relative heights of features on the ground struck by the laser pulses.

model     A simulation of a real-world event (usually using a computer) that has been developed to predict one or more likely outcomes. Or an individual that is meant to display how something would work in or look on others.

native     Associated with a particular location; native plants and animals have been found in a particular location since recorded history began. These species also tend to have developed within a region, occurring there naturally (not because they were planted or moved there by people). Most are particularly well adapted to their environment.

online     (n.) On the internet. (adj.) A term for what can be found or accessed on the internet.

Pacific     The largest of the world’s five oceans. It separates Asia and Australia to the west from North and South America to the east.

physical     (adj.) A term for things that exist in the real world, as opposed to in memories or the imagination. It can also refer to properties of materials that are due to their size and non-chemical interactions (such as when one block slams with force into another).

range     The full extent or distribution of something. For instance, a plant or animal’s range is the area over which it naturally exists.

resolution     (in optics) A term having to do with the degree of clarity or detail with which some object can be seen. (v. resolve)

risk     The chance or mathematical likelihood that some bad thing might happen. For instance, exposure to radiation poses a risk of cancer. Or the hazard — or peril — itself. (For instance: Among cancer risks that the people faced were radiation and drinking water tainted with arsenic.)

satellite     A moon orbiting a planet or a vehicle or other manufactured object that orbits some celestial body in space.

sea     An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty.

sea level     The overall level of the ocean over the entire globe when all tides and other short-term changes are averaged out.

species     A group of similar organisms capable of producing offspring that can survive and reproduce.

sustainability     (adj: sustainable) To use resources in a way that they will continue to be available in the future.

virtual reality     A three-dimensional simulation of the real world that seems very realistic and allows people to interact with it. To do so, people usually wear a special helmet or glasses with sensors.


Journal: P. Ezcurra-Isabel and I. Rivera-Collazo. An assessment of the impacts of climate change on Puerto Rico's Cultural Heritage with a case study on sea-level rise. Journal of Cultural Heritage. Vol. 32, July-August 2018, p. 198. doi: 10.1016/j.culher.2018.01.016.

Report: M. Howey. Climate change, sea-level rise, and the vulnerable cultural heritage of coastal New Hampshire. Carsey School of Public Policy, University of New Hampshire. Durham, N.H.: Spring 2018.

Journal: M.D. McCoy. The race to document archological sites ahead of rising sea levels: Recent applications of geospatial technologies in the archaeology of Polynesia. Sustainability. Vol. 10, January 14, 2018. doi: doi:10.3390/su10010185.

Journal: D. Anderson et al. Sea-level rise and archaeological site destruction: An example from the southeastern United States using DINAA (Digital Index of North American Archaeology). PLOS One. Vol. 12, November 29, 2017. doi: 10.1371/journal.pone.0188142.

Database: D. Anderson et al. Digital Index of North American Archaeology