Ancient Scandinavians may have sailed 100 km between Denmark, Norway

A new simulation suggests that ancient people in northern Denmark and southwestern Norway may have traveled directly between the two regions, crossing more than 100 kilometers (62 miles) of open ocean, according to The Independent. This challenges previous beliefs that cultural exchange during the Bronze Age was facilitated solely by vessels traveling along the coastlines of Scandinavia.

Similarities between the Bronze Age cultures of northern Denmark and southwestern Norway—including artifacts, burial systems, and architecture—have long suggested that people were traveling between these regions. Researchers developed a computer model to simulate different routes between southwestern Norway and northern Denmark, incorporating data on environmental factors such as currents and wind, as well as information on how vessels move through the water. They simulated trips using a reconstruction of the Hjortspring boat, a large paddle-driven canoe from around 350 BCE, approximately 20 meters in length, discovered in 1921 in southern Denmark.

The simulations showed that Bronze Age people likely had the ability to travel directly from Denmark to Norway over the open ocean. These trips would have required a boat capable of navigating in waves up to one meter high and winds of up to 10 knots, along with good weather forecasting and navigational skills. The seafarers would have needed extensive maritime know-how to undertake such voyages.

While the longer route along the coastline was safer and possible year-round, the direct open-ocean crossings were likely limited to the summer months. The coastal route—following a 700-kilometer path across Denmark, up the coast of Sweden, and back down to southwestern Norway—would have required frequent stops to restock supplies and taken many weeks to complete.

"Successful journeys needed crews with extensive maritime know-how and seafaring skills," the scientists said, according to The Independent. They added that the seafarers would have needed good weather forecasting and navigation skills to undertake the direct crossings.

According to the simulations, regular crossings of the Skagerrak, including some 50 kilometers of no visible land, likely commenced by 2300 BCE as indicated by archaeological evidence. The study, led by Boel Bengtsson, suggests that systematic and regular crossings over long stretches of open sea were possible in vessels similar to the Hjortspring boat. "Our findings show that systematic and regular crossings over long stretches of open sea were possible in vessels similar to the Hjortspring boat and that such journeys might have begun already by c. 2300 BCE," the researchers wrote.

The research team published their findings in the journal PLOS One. They developed a modeling program that could also be adapted to study other seafaring cultures, given sufficient information about the shape and specifications of their vessels. "This tool offers a new way to assess navigation and seafaring abilities in prehistory while also enabling the direct comparison between different type vessels and vessel configuration, navigational skills and propulsion," the researchers wrote.

These findings suggest that the cultural exchange between northern Denmark and southwestern Norway during the Bronze Age may have been facilitated not only by coastal voyages but also by direct open-sea crossings.

The article was written with the assistance of a news analysis system.