Playing in mud – this week in Archaeology 07.03.17

When I was growing up I really wanted to be an archaeologist.   I later changed my mind and life took me in different directions.   However, to this day I love reading about people digging historical clues out of the ground and applying the this evidence to our knowledge of history. Through archaeology the scientific method is applied to the study of history.

So I’m hoping to do a regular series of blog posts on what’s happening in the world of Archaeology.  It makes a nice change from writing about Donald Trump

A fascinating article in the Smithsonian provides a vivid illustration of how our theories about historical events, in this case the collapse of the Norse Greenland colony in the 14th Century, can change based on archaeological discoveries.

Until very recently the scientific consensus, as famously publicized in Jared Diamond’s book Collapsed was that a worsening climate in the 14th century and over farming by the Norse settlers led the rapid collapse of the Greenland colony.

The problem with the settlements, Diamond argues, was that the Norse thought that Greenland really was green; they treated it as if it were the verdant farmland of southern Norway. They cleared the land to create meadows for their cows, and to grow hay to feed their livestock through the long winter. They chopped down the forests for fuel, and for the construction of wooden objects. To make houses warm enough for the winter, they built their homes out of six-foot-thick slabs of turf, which meant that a typical home consumed about ten acres of grassland.

But Greenland’s ecosystem was too fragile to withstand that kind of pressure. The short, cool growing season meant that plants developed slowly, which in turn meant that topsoil layers were shallow and lacking in soil constituents, like organic humus and clay, that hold moisture and keep soil resilient in the face of strong winds. “The sequence of soil erosion in Greenland begins with cutting or burning the cover of trees and shrubs, which are more effective at holding soil than is grass,” he writes. “With the trees and shrubs gone, livestock, especially sheep and goats, graze down the grass, which regenerates only slowly in Greenland’s climate. Once the grass cover is broken and the soil is exposed, soil is carried away especially by the strong winds, and also by pounding from occasionally heavy rains, to the point where the topsoil can be removed for a distance of miles from an entire valley.” Without adequate pastureland, the summer hay yields shrank; without adequate supplies of hay, keeping livestock through the long winter got harder. And, without adequate supplies of wood, getting fuel for the winter became increasingly difficult.

Oh those silly Norse.  The theory held that as the climate deteriorated and the productivity of the land fell due to poor farming practices the settlers we weakened and eventually succumbed to starvation and disease.  It’s usually followed with the suggestion that if only the Norse had been wise enough to learn from the Inuit civilization However there’s always been a problem with this theory – a lack of hard evidence.  High Medieval Norse civilization is famous amongst other things for it’s prolific written literature.  The best known contemporary records are the Norse Sagas which amongst other things chronicle the settlement of Greenland but more prosaic written sources such as legal records exist as well.   However there’s nothing in the written records to indicate that the Greenland colonists were suffering and dying.

However the latest research, as chronicled in the Smithsonian story paints a very different picture of the Greenland Norse – a sophisticated group of people who rapidly adapted to their harsh environment and pursued a successful and lucrative economic strategy that lasted for several centuries until catastrophic events elsewhere made made it no longer viable.  Whereas the previous theory claims that the Greenland Colony collapsed because the settlers refused to adapt to the local conditions and to eat a diet similar to that of the Inuit, excavations of Norse midden have revealed that the settlers rapidly adapted to a sea-food centric diet:

He and his team of seven students have spent several weeks digging into a midden—a trash heap—just below the homestead’s tumbled ruins. On a cold, damp morning, Cameron Turley, a PhD candidate at the City University of New York, stands in the ankle-deep water of a drainage ditch. He’ll spend most of the day here, a heavy hose draped over his shoulder, rinsing mud from artifacts collected in a wood-framed sieve held by Michalina Kardynal, an undergraduate from Cardinal Stefan Wyszynski University in Warsaw. This morning they’ve found a delicate wooden comb, its teeth intact. They’re also finding seal bones. Lots of them.

“Probably about 50 percent of all bones at this site will be seal bones,” Smiarowski says as we stand by the drainage ditch in a light rain. He speaks from experience: Seal bones have been abundant at every site he has studied, and his findings have been pivotal in reassessing how the Norse adapted to life in Greenland. The ubiquity of seal bones is evidence that the Norse began hunting the animals “from the very beginning,” Smiarowski says. “We see harp and hooded seal bones from the earliest layers at all sites.”

A seal-based diet would have been a drastic shift from beef-and-dairy-centric Scandinavian fare. But a study of human skeletal remains from both the Eastern and Western settlements showed that the Vikings quickly adopted a new diet. Over time, the food we eat leaves a chemical stamp on our bones—marine-based diets mark us with different ratios of certain chemical elements than terrestrial foods do. Five years ago, researchers based in Scandinavia and Scotland analyzed the skeletons of 118 individuals from the earliest periods of settlement to the latest. The results perfectly complement Smiarow­ski’s fieldwork: Over time, people ate an increasingly marine diet, he says.

It’s raining heavily now, and we’re huddled beneath a blue tarp next to the midden, sipping coffee and ingesting some terrestrial chemical elements in the form of cookies. In the earliest days of the settlements, Smiarowski says, the study found that marine animals made up 30 to 40 percent of the Norse diet. The percentage steadily climbed, until, by the end of the settlement period, 80 percent of the Norse diet came from the sea. Beef eventually became a luxury, most likely because the volcano-induced climate change made it vastly more difficult to raise cattle in Greenland.

So as it turns out the Norse did adapt to their new environment.  Even in the early days of the colony, European style agriculture was incapable of supplying the settlers with sufficient food, so they supplemented their diet with seal meat. Norse technology – seagoing ships, and iron weapons would have made them very effective seal hunters. Ironically, across Baffin Bay in what is now northern Quebec and Nunavut, the native Dorset Culture people (precursors to the Inuit) may have been dying out due to a failure to adapt to the warmer climate of the late Middle Ages.

The evidence also suggests that the Norse were also responsible hunters,

Judging from the bones Smiarowski has uncovered, most of the seafood consisted of seals—few fish bones have been found. Yet it appears the Norse were careful: They limited their hunting of the local harbor seal, Phoca vitulina, a species that raises its young on beaches, making it easy prey. (The harbor seal is critically endangered in Greenland today due to overhunting.) “They could have wiped them out, and they didn’t,” Smiarowski says. Instead, they pursued the more abundant—and more difficult to catch—harp seal, Phoca groenlandica, which migrates up the west coast of Greenland every spring on the way from Canada

The Norse settlers’ stewardship of their environment wasn’t limited to the seal hunt either.  Other evidence suggests that they were also able to improve the productivity of the land they farmed.

When the Norse arrived in Greenland, there were no locals to teach them how to live. “The Scandinavians had this remarkable ability to colonize these high-latitude islands,” says Andrew Dugmore. “You have to be able to hunt wild animals; you have to build up your livestock; you have to work hard to exist in these areas….This is about as far as you can push the farming system in the Northern Hemisphere.”

And push it they did. The growing season was short, and the land vulnerable to overgrazing. Ian Simpson has spent many seasons in Greenland studying soil layers where the Vikings farmed. The strata, he says, clearly show the impact of their arrival: The earliest layers are thinner, with less organic material, but within a generation or two the layers stabilized and the organic matter built up as the Norse farmwomen manured and improved their fields while the men were out hunting. “You can interpret that as being a sign of adaptation, of them getting used to the landscape and being able to read it a little better,” Simpson says.

Still, no matter how good of farmers the Greenland Norse may have been, any diet made up in large part of seal meat sounds pretty miserable, so why even settle there in the first place.  The answer seems to have been ivory from walrus tusks.  At this time ivory was extremely hard to come by in Europe and consequently very expensive.   The Greenland Norse appear to have done a roaring trade in the stuff, sending it back to Norway in exchange for food, and manufactured goods.

Then, beginning in the 14th Century a combination of factors (famine in Europe, the Black Death, changing consumer tastes, and the emergence of rival sources of ivory):

Then, in the 13th century, after three centuries, their world changed profoundly. First, the climate cooled because of the volcanic eruption in Indonesia. Sea ice increased, and so did ocean storms—ice cores from that period contain more salt from oceanic winds that blew over the ice sheet. Second, the market for walrus ivory collapsed, partly because Portugal and other countries started to open trade routes into sub-Saharan Africa, which brought elephant ivory to the European market. “The fashion for ivory began to wane,” says Dugmore, “and there was also the competition with elephant ivory, which was much better quality.” And finally, the Black Death devastated Europe. There is no evidence that the plague ever reached Greenland, but half the population of Norway—which was Greenland’s lifeline to the civilized world—perished.

The Norse probably could have survived any one of those calamities separately. After all, they remained in Greenland for at least a century after the climate changed, so the onset of colder conditions alone wasn’t enough to undo them. Moreover, they were still building new churches—like the one at Hvalsey—in the 14th century. But all three blows must have left them reeling. With nothing to exchange for European goods—and with fewer Europeans left—their way of life would have been impossible to maintain. The Greenland Vikings were essentially victims of globalization and a pandemic.

The question of what happened to the Greenland Norse is still unanswered.  Some archaeologists still believe that in the they starved to death.  Others believe that they simply packed up and returned to the lands of their ancestors, Iceland and Norway.   Personally I tend to the latter theory.  The famines and Black Death of the 14th century wiped out between 30% and 50% of Europes population.   This may have destroyed the ivory trade but it also opened led to a labour shortage and a rise in wages and other opportunities.  Where one door closes another opens.

Europe was devastated by the plague. Entire villages were emptied and abandoned as what was left of the rural population flocked to the towns. Widespread economic change and a decrease in the population led to a depression that lasted for decades. In comparison to Norway, however, the effects of the plague in Iceland were minimal. It took the Norwegian nation nearly two hundred years to recover from the social upheaval that had been a direct result of the plague. In Iceland, there was hardly any social change at all to speak of. Instead, there was an increasing demand for workers and a corresponding rise in wages. Those farmsteads that had been deserted while the plague raged through the country now stood empty and ready to be leased out. As a consequence the cost of renting decreased. Indeed, one may say with some conviction that ordinary people who were brought up in Iceland after the plague enjoyed much better economic conditions than their parents. There was plenty of work to be had and there were empty farmsteads all over the country to be taken over for a low price.

Why eat seal when there’s better opportunities elsewhere?

“You can live on it, but it tastes like shit.” Mick Dundee

One last thing to take away from the Smithsonian article is how important it is for scientists to remain open minded to new evidence. One of the Archaeologists featured, Thomas McGovern was influential in the development of the previous theory of poor adaption to a hostile climate as the cause for the collapse of the Greenland Colony.  And yet he seems pretty relaxed about his theory mimicking the fate of the Greenland Colony itself:

Thomas McGovern used to think he knew. An archaeologist at Hunter College of the City University of New York, McGovern has spent more than 40 years piecing together the history of the Norse settlements in Greenland. With his heavy white beard and thick build, he could pass for a Viking chieftain, albeit a bespectacled one. Over Skype, here’s how he summarized what had until recently been the consensus view, which he helped establish: “Dumb Norsemen go into the north outside the range of their economy, mess up the environment and then they all die when it gets cold.”…

But over the last decade a radically different picture of Viking life in Greenland has started to emerge from the remains of the old settlements, and it has received scant coverage outside of academia. “It’s a good thing they can’t make you give your PhD back once you’ve got it,” McGovern jokes. He and the small community of scholars who study the Norse experience in Greenland no longer believe that the Vikings were ever so numerous, or heedlessly despoiled their new home, or failed to adapt when confronted with challenges that threatened them with annihilation.

“It’s a very different story from my dissertation,” says McGovern. “It’s scarier. You can do a lot of things right—you can be highly adaptive; you can be very flexible; you can be resilient—and you go extinct anyway.” And according to other archaeologists, the plot thickens even more: It may be that Greenland’s Vikings didn’t vanish, at least not all of them.

In a world where inconvenient data is sometimes changed in order to preserve a favoured narrative it’s always nice to see a scientist with the humility to know that we in fact know very little.



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