In northern Europe, the most vulnerable periods of prehistory are not to be discovered in the earth but beneath the water. Off the coast of Aarhus, Denmark’s second-largest city, a Mesolithic settlement lies beneath 25-26 feet of water in the Bay of Aarhus, a full shoreline village lost when the post-Ice Age rise of the sea quickened to the point of remapping the region in a matter of generations.
The recovery itself is as much an engineering endeavor as it is an archaeological one. The divers methodically cross the bottom of the sea, using suction to remove sediment and isolate artifacts without disturbing the context in which they are found. This has resulted in the site producing stone tools, arrowheads, animal bones, a tooth from a seal, and wood, which would not normally last thousands of years on dry land. The low oxygen content of the bay created a kind of vault that preserved organic materials that would otherwise have decomposed.
The significance of the Aarhus find is that it is located in an ancient coastal area, which is more significant than if it were located in an inland area. Most of the Stone Age finds in the area are located in areas that were formerly close to the coastline but are now agricultural areas and forests, and in this case, the group is studying the area where the settlement is “positioned directly at the coastline,” as stated by underwater archaeologist Peter Moe Astrup.
“What we actually try to find out here is how was life at a coastal settlement,” he said.
It is also important to take into consideration the timing of these events. About 8,500 years ago, the Earth was still recovering from the last Ice Age, and the Baltic and North Sea coastlines were undergoing rapid change. In the area of research in Denmark, the rate of rise of the sea level has been determined to be 6.5 feet per century, which would have been a normal process of uprooting camps, paths, and known fishing grounds.
The underwater archaeological site of Aarhus offers the special opportunity of viewing this process not on a graph but through the artifacts that people left behind. “It’s like a time capsule,” Astrup said. “When the sea level rose, everything was trapped in this oxygen-free environment time just stops.” He added,“We find completely well-preserved wood. We find hazelnut. Everything is well preserved.”This approach to preservation can make small finds big evidence.
Wood can show how wood-working was done and how wood was repaired; nut shells and bones can show season and diet; microscopic evidence can show activity areas in a lived space. Researchers in Denmark are also attempting to apply the principles of dendrochronology to date when the tree stumps under the water off the coast of Denmark died as the water rose to claim them, to fix human history to this specific environmental event. Aarhus is only a small part of a much larger drowned landscape.
The most famous example of this in Europe is Doggerland, the land bridge that once existed between Britain and the mainland, which is now lost under the North Sea. More recent mapping has begun to uncover the specifics of its rivers, marshes, and hills, including over 45,000 square kilometers of drowned landscape, hidden in seismic data originally used for the offshore industry. In addition, other projects are also being pushed forward off the coasts of the Baltic and North Seas by the new build-out offshore.
A long-term project, which is EU-funded, involves teams of researchers from Denmark, the UK, and Germany working together to find Mesolithic settlements in areas where sea infrastructure is being constructed, with the seabed being considered cultural territory that can be surveyed, mapped, and excavated if necessary. The “Atlantis” label has stuck because it encapsulates a simple truth: shorelines can disappear. The engineering feat is not the lost city but the technology divers, suction excavation, tree-ring dating, seafloor mapping that can make a lost shoreline reappear as evidence of how life once existed on the edge of a fluctuating sea.
