7 Scientific Tools Archaeologists Use to Uncover the Viking World

New archaeological tools continue to give archaeologists innovative means of interrogating the past. These advances bring experts closer than ever to understanding the Viking world.

Feb 28, 2024By Rachel Morgan, MA Medieval Archaeology, BA History & Anthropology
viking archaeology


Science loves the Vikings. NASA’s 1970s mission to Mars paid homage to the Vikings, and Bluetooth wireless technology takes its name from the Viking king of Denmark and Norway, Harald Bluetooth. The Bluetooth symbol on phones and computers also hails from Viking runes. Science has become essential to uncovering Viking archaeology, and new archaeological tools have allowed us to better understand the Viking world.


1. Strontium Isotope Analysis and Viking Archaeology

trelleborg fortress with road
The Trelleborg Fortress in Zealand, Denmark is a UNESCO world heritage site, Source: the National Museum of Denmark, Copenhagen


The Trelleborg Fortress located in Zealand, Denmark is a circular fortification divided into four quadrants. Inside each quadrant are longhouses. On its own, the fortress is an archaeological marvel, but the more archaeologists dig into the fortress, the more exceptional the monument proves to be.


King Harald Bluetooth organized defensive fortifications across the Viking world to maintain power during the 10th century. Excavations in Zealand from 1938-1940 revealed a fortification associated with Bluetooth’s reign and 157 buried individuals. But who were these people?


viking archaeology denmark trellborg fortress
The ruins of the Trellborg Fortress in Zealand, Denmark, Source: National Museum of Denmark, Copenhagen


Archaeologists turned to a technique called strontium isotope analysis. Strontium is a naturally occurring element present in most rocks, but its isotopes vary due to geology. Strontium isotopes move from rocks to water and plants, which humans absorb when they eat and drink.

Get the latest articles delivered to your inbox

Sign up to our Free Weekly Newsletter


In children, strontium isotopes accumulate in tooth enamel. Tooth enamel does not change after childhood, so archaeologists can use the strontium isotopes in tooth enamel to determine where a person was born or spent their childhood. Strontium also gathers in bone but evolves over a seven-to-ten-year periods. Thus, archaeologists can also evaluate strontium isotopes in bone to understand if a person migrated at the end of their lives.


viking archaeology harald bluetooth coin
Coins from the reign of Harald Bluetooth, Source: the British Museum


Archaeologists selected 48 individuals from the burial ground associated with the Trelleborg fortress in Zealand. Analyzing their tooth enamel, scientists found that this group of people originated from many different places. Over half of the people assessed spent their childhood outside of southern ScandinaSource:.


This finding surprised archaeologists who expected most of the people buried here to hail from Denmark. Based on the results, archaeologists proposed that many people came from Norway, the Baltic, and other foreign areas to join the army during Harald Bluetooth’s reign. It seems that many never made it back home.


2. Dendrochronology

oseberg ship viking archaeology
The Oseberg is a clinker-built ship from the Viking Age, photo by Petter Ulleland, Source: Wikimedia Commons


During the 1920s, a ship emerged from the west coast of Norway. Farmers cutting up a peat bog discovered the remains of multiple sailing vessels. Analysis revealed that one of the vessels was a clinker-built ship and the other was a small, clinker-built boat. They became known as the Kvalsund ships.


People in ScandinaSource: built clinker-style vessels long before the Vikings began raiding and trading around the medieval world. Based solely on the ships, archaeologists were left with several questions. When were the ships built? And by whom?


Dendrochronology is an archaeological technique also commonly referred to as tree ring dating. The insides of trees conceal concentric growth rings that scientists can assign calendar dates to. Vikings felled trees for several sorts of artifacts, including game boards, chests, caskets, and most notably ships. For the Kvalsund vessels, archaeologists applied dendrochronology to understand when they were built and how they fit into the history of shipbuilding in Iron Age Norway.


Dendrochronology dated the ship to around 780-800 CE. This date supported archaeologists’ interpretation that the ship was buried as a cultic offering during the transition to the Viking Age. It represents the social and technological changes in the Norse world during that period.


3. ZooMS: Fingerprinting the Viking Animal Kingdom

viking comb
Viking Age comb, Source: the Swedish History Museum, Stockholm


The Vikings were the masters of various crafts. They often used the bones of animals to create intricate items. They made combs, game pieces, pins, needles, and musical instruments from the bones of animals big and small. While these artifacts offer insight into what was important in the Viking world, they also show what resources were available to the medieval Norse.


The bones these artifacts were made from also indicate how the Vikings spent their time and where. Archaeologists can identify parts of animals and even species of animals by analyzing bones. Once bones have been carved into new objects, this becomes more difficult, so archaeologists have looked to science to overcome this obstacle.


viking game pieces
Game pieces made from whale bone and walrus tusk, Source: Swedish History Museum, Stockholm


Artifacts made from animal bones, fur, and shells retain collagen and proteins from that creature. Scientists can extract collagen and other proteins from artifacts and determine what species of animal the artifact was made from using Zooarchaeology by Mass Spectrometry (ZooMS). ZooMS is a type of peptide mass fingerprinting that allows archaeologists to identify animal species by their molecular fingerprints.


viking antler comb
Viking age antler comb, Source: Swedish History Museum, Stockholm


Archaeologists have used ZooMS to better understand many Viking Age artifacts. Game pieces from Sweden were analyzed by ZooMS and proved to be made of whalebone. From the sample of whalebone game pieces tested, only one species of whale was identified: the endangered North Atlantic right whale.


Based on these findings, archaeologists propose that ScandinaSource:ns hunted whales long before the Viking Age and established trading routes later used by the medieval Norse. Archaeologists also used ZooMS to assess hair combs made from antlers. ZooMS showed the Vikings made combs out of reindeer antlers by at least 780 CE. This suggests that the Vikings used long-established trade routes in the southern North Sea. From hunting whales to collecting reindeer antlers ZooMS continues to shed light on the busy lives of the Vikings.


4. Geophysics

viking archaeology aggersborg
The Aggersborg Fortress, Source: the Vesthimmerlands Museum, Søndergade


Trouble seemed to follow the Vikings around the medieval world. Norse rulers found it necessary to prepare for attacks on their kingdoms by constructing large fortifications. The largest of these fortresses is called Aggersborg. Located in Denmark, Aggersborg consists of both a ring fortress and a settlement that existed before the construction of the fortress.


Although archaeologists have long known the location of Aggersborg Fortress and its historical significance, they had no idea how big or small the fortification or the settlement actually was. Digging up the entire fortress was not an option and archaeologists needed a way to get a sense of what waited for them under the earth.


viking archaeology geophysics
Archaeologists conducting a geophysical survey, Source: the Museum of London


Geophysics offers archaeologists a toolbox of surveying techniques. Using geophysical tools, archaeologists can detect underground features not evident on the surface of the earth. One type of geophysical survey is ground penetrating radar, a radar that transmits electromagnetic pulses into the ground. Those pulses hit the ground and materials in the earth like walls or pipes, and produce reflections.


Scholars measure the time it takes for those reflections to return to the point of transmission. That time gives archaeologists a sense of how deep a feature is and how many points of interest may lie underground. Archaeologists can then begin excavating to determine what those features might be.


At Aggersborg, ground penetrating radar in combination with other geophysical techniques revealed preserved timber structures in the fortress rampart and sunken building features. The survey provided archaeologists with a hint of all that they still had to learn about the Viking ring fortress.


5. Radiocarbon Dating

viking archaeology beads
Glass beads from the Viking Age, Source: the Swedish History Museum, Stockholm


The Viking Age fascinates scholars for many reasons. One area of interest is the Vikings’ connectivity to Europe, the Baltic, and the Near East. Scholars question whether the Vikings pioneered far-reaching trade routes, or if they simply capitalized on routes that predated their raids of the medieval world. To answer this question, archaeologists needed to be able to analyze artifacts and sites to precisely determine the chronology.


There are two kinds of dating in archaeology: absolute and relative dating. Absolute dating measures physical properties in artifacts to determine the object’s age. Relative dating is a less precise manner of dating that allows archaeologists to determine an artifact’s date in relation to other objects or cultural features.


viking brooch
Viking Age brooches, Source: the Swedish History Museum, Stockholm


For absolute dating, archaeologists use radiocarbon dating. The Earth is full of carbon isotopes. Stable carbon isotopes are known as carbon 12 (12C). Unstable carbon isotopes are known as carbon 14 (14C). When things die, the carbon 14 isotopes begin to decay at a constant rate. Scientists can count the number of stable carbon isotopes and carbon 14 isotopes in objects. They assess the ratio between stable carbon isotopes and carbon 14 isotopes to estimate age.


On the other hand, archaeologists have used relative dating by evaluating the stratigraphy of the Viking trade center Ribe. Stratigraphy relies on the law of superposition, which contends that the earth forms in layers and the lower layers form before the upper layers of the earth. The lower layers are thus older.


Combining these approaches, archaeologists found evidence from beads, brooches, and combs that maritime trade routes of the Viking Age were in place long before the Vikings raided Lindisfarne. Radiocarbon dating in combination with other techniques has thus helped archaeologists revise a long-held historical timeline.


6. Electron Microscopes

viking archaeology ring allah
Ring inscribed with the word Allah, Source: the Swedish History Museum, Stockholm


Trade was crucial to the Vikings. On the island of Björkö in Lake Mälaren, the Vikings established a trade center called Birka. Many of the people buried in and around the trade center were buried with rich grave goods. In one grave, archaeologists found no evidence of a body, but they did find clothing, brooches, scissors, a needle case, glass, rock crystal and carnelian beads, and a ring. The ring consisted of violet amethyst glass with a silver band.


Archaeologists took a closer look at the ring using a scanning electron microscope. A scanning electron microscope produces images with electrons instead of light. The scanning electron microscope revealed an inscription on the amethyst ring from Birka. The ring reads “Allah” and provides evidence of Viking ties to religions based in the Near East.


7. Genomics

viking warrior figurine
Viking Age female warrior figurine, c. 800 CE, Source: the British Museum


In another grave at Birka, archaeologists uncovered the grave of a warrior buried with an impressive cache of weapons and other burial goods. The body lay surrounded by a sword, an ax, a knife, two lances, two shields, and 25 arrows. Along with weapons, the warrior was buried with bone game pieces and two horses.


Archaeologists initially assumed the grave was that of a male warrior. Female warriors have existed throughout history, but male warriors are more common. Over the years, archaeologists began to wonder if perhaps the Viking warrior was female. This time, scholars turned to genomics to explore the question.


viking archaeology sword
Viking Age sword, Source: the Swedish History Museum, Stockholm


Genomics is the science of mapping genomes and using genomics, archaeologists were able to map and assess the Birka warrior’s DNA. The results of the study showed that the warrior had two X chromosomes and was born a female.


The Viking Age woman warrior from Birka highlighted the diversity of women’s lives during the Viking Age. While many women lived rural lives that centered around the home, many others moved to urban trading ports where they worked in the craft industry. The Viking Age witnessed Norse queens, Norse seeresses, and — as proven by science — Norse women warriors.


Science has helped archaeologists shine a light on the complexity of women’s lives during the Viking Age and has corrected mistaken interpretations. As scientific techniques continue to evolve and advance, archaeologists can look forward to learning more about the Viking world.

Author Image

By Rachel MorganMA Medieval Archaeology, BA History & AnthropologyRachel Morgan is an archaeologist interested in material culture studies, small finds, regulatory compliance, and conflict archaeology. She holds a MA in Medieval Archaeology from the University of York and a BA in History and Anthropology from the University of Alabama at Birmingham.