Seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them. This idea played a pivotal role in the development of the theory of plate tectonics, which revolutionized geologic thought during the last quarter of the 20th century. The crater is the first of its kind ever found on Greenland — or under any of the Earth’s ice sheets — and is among the 25 largest known. Human evolution theory may soon be turned on its. Greenland, meanwhile, was not “discovered” (by Norsemen, that is) until a century or so later, when a Norwegian who was sailing to Iceland was blown off course. It was later named “green land” by Erik the Red, another Norwegian, who really was fleeing from Norway and first went to Iceland before settling in Greenland.
The continent of North America has been inhabited by humans for at least 16,500 years. As early as the 1500s, early settlers and European thinkers were interested in discovering how humans had come to populated North and South America. One theory suggested the migration of Norsemen across Greenland into North America. Another theory proposed the island of Atlantis as the origins of human life in the New World. Yet another idea proposed that the inhabitants had generated out of mud. However, by the early 1800s scientists and theorists began discussing the possibility of a land bridge that had spanned between Asia and North America thousands of years ago. The theory of a land bridge has fueled the imagination of explorers and scientists for centuries.
Early Theory of Fray Jose de Acosta
In 1590, the Spanish missionary Fray Jose de Acosta produced the first written record to suggest a land bridge connecting Asia to North America. The question of how people migrated to the New World was a topic widely debated among the thinkers and theorists of his time. Acosta rejected many of the theories proposed by his contemporaries. Instead, he believed that hunters from Asia had crossed into North America via a land bridge or narrow strait located far to the north. He thought the land bridge was still in existence during his lifetime.
The Bering and Cook Expeditions
During the eighteenth century, Peter the Great, the Russian Czar from 1682 to 1725, chartered an exploration of the eastern borders of the Russian Empire. He recruited the Danish explorer Vitus Bering to lead an expedition in the Bering Strait region. Before the expedition, maps of Siberia sometimes contained a large landmass across the water from the Chukchi Peninsula; however no definite account of travel through the strait had been recorded by the early seventeen hundreds.
The two voyages of Bering, the first in 1724 and the second in 1741, confirmed what many people living on the Chukchi Peninsula already knew. That there was land and even people across the water; people who had been trading and traveling across the Bering Strait for thousands of years. The second explorer to confirm the existence of present day Alaska was the Englishman, Captain James Cook. On his 1778 expedition he produced detailed maps of the Alaskan coast. The results of his exploration helped enlighten the outside world about the Bering Strait region. As news about Bering and Cook's travels reached Russia, Europe, and other parts of the world, theories of human migration between Asia and North America gained strength.
The Land Bridge Theory
The conformation of a strait between Asia and North America fueled an interest in the possibility of a wide plain that might have connected the two continents. Beginning in the early 1800s, American scientists and naturalists started investigating archeological sites on the east coast of the United States, slowly working their way towards the west coast. The findings of these forebearers to modern archaeology suggested that people hadn't originated in North America but had populated the continent from another place. However, from where and how had yet to be discovered. From about 1890 to 1925, research, discussion, and inquiry about the peopling of North America stalled because of inconclusive data. It wasn't until the mid-1920s that scientists would finally restart the search for evidence of how people came to North America.
David M. Hopkins
David M. Hopkins studied geology at the University of New Hampshire before accepting a position with the U.S. Geological Society in 1942. His first trip to Alaska planted a seed of fascination for the wild and beautiful landscape of the area. During his lifetime, Hopkins spent many of his summers on the Seward Peninsula often researching geology in the area that later became the preserve. He made several key contributions to the study of Beringia; he helped publish two books that contained papers written by researchers from a wide range of backgrounds and collaborated with many scientists and researchers to make groundbreaking discoveries about the Bering Land Bridge.
For years, scientists speculated about the different types of vegetation that might have been found on the land bridge. Some scientists believed the land bridge contained uniformed vegetation similar to the current arctic plain vegetation. Hopkins and several other scientists were convinced the land bridge had supported a more diverse vegetation, with plants growing in response to elevation variations and the amount of surface water. Hopkins worked with Mary Edwards, Claudia Hofle, and Victoria Goetcheus Wolf,
to confirm the age of plants frozen in a layer of ash from an eruption at Devil Mountain 18,000 years ago.The age of the plant matter found in the ash coincided with the last proposed opening of the land bridge. The ash covered a wide area of what would have been the middle of the land bridge (north to south) 18,000 years ago .The findings from their collaboration helped to confirm that the type of vegetation on the land bridge had been more diverse than originally thought.
to confirm the age of plants frozen in a layer of ash from an eruption at Devil Mountain 18,000 years ago.The age of the plant matter found in the ash coincided with the last proposed opening of the land bridge. The ash covered a wide area of what would have been the middle of the land bridge (north to south) 18,000 years ago .The findings from their collaboration helped to confirm that the type of vegetation on the land bridge had been more diverse than originally thought.
Hopkins had a special ability to forge connections between scientists and researchers from many backgrounds. He linked research conducted by people across many different disciplines to strengthen the concept of the Bering Land Bridge Theory. Hopkins reached out to scientists and researchers studying the Chukotka Peninsula and brought their work to the attention of researchers and scientists studying the Seward Peninsula. He recognized the need for interdisciplinary study to understand the whole picture of Beringia. His passion for the Bering Land Bridge was instrumental in not only creating the Bering Land Bridge National Preserve but also in building interest in the Bering Land Bridge Theory.
A shipload of visitors arrived in the fjord overnight, so Ingibjorg Gisladottir dressed like a Viking and headed out to work in the ruins scattered along the northern edge of this tiny farming village.
Qassiarsuk is tiny (population: 56), remote, and short on amenities (no store, public restrooms, or roads to the outside world), but some 3,000 visitors come here each year to see the remains of Brattahlid, the medieval farming village founded here by Erik the Red around the year 985.
When they arrive, Ms. Gisladottir, an employee of the museum, is there to greet them in an authentic hooded smock and not-so-authentic rubber boots. 'There were more visitors this year than last,' she says. 'People want to know what happened to the Norse.'
The Greenland Norse colonized North America 500 years before Christopher Columbus 'discovered' it, establishing farms in the sheltered fjords of southern Greenland, exploring Labrador and the Canadian Arctic, and setting up a short-lived outpost in Newfoundland.
But by 1450, they were gone, posing one of history's most intriguing mysteries: What happened to the Greenland Norse?
There are many theories: They were starved off by a cooling climate, wiped out by pirates or Inuit hunters, or perhaps blended into Inuit society as their own came unglued.
The Greenland Theory Movie
Now scientists are pretty sure they have the answer: They simply up and left.
'When the climate deteriorated, and their way of life became more difficult, they did what people have done throughout the ages: They looked for a more opportune place to live,' says Niels Lynnerup, a forensic anthropologist at the University of Copenhagen in Denmark who studies the Norse.
Climate change was clearly driving the Norse, with their sheep- and cattle-farming traditions, to the edge of survival. With the onset of the Little Ice Age (from 1300 to 1850), conditions deteriorated across the Norse lands, particularly for people living on marginal farmland in Iceland, northern Norway, and Greenland.
Today, Greenland is warming up, with residents witnessing dramatic changes over the past five years. Winter sea ice, which the indigenous Inuit people in north Greenland traditionally relied on for sled dog transportation and seal hunting, has stopped forming reliably and robustly. Meanwhile, farmers in southerly communities like Qassiarsuk have enjoyed a markedly expanded growing area and season. Potatoes, previously confined to the far south, now grow as far north as the capital, Nuuk, 185 miles south of the Arctic Circle.
A slowly cooling climate in 1300s
In the late 1300s, Norse Greenlanders likely experienced this process in reverse, their farms squeezed by advancing glaciers and truncated summers. It's no accident, anthropologists say, that the cold-adapted Inuit were spreading south in this period, their hunting territory eventually overlapping with the Norse.
Scholars have wondered why the Norse failed to adapt, dropping agriculture in favor of hunting and fishing, like the Inuit. Turns out, they did – up to a point. An analysis of the bones of Norse buried at Brattahlid and other Norse sites found that early settlers ate a diet consisting of 80 percent agricultural products and 20 percent seafood; from the 1300s, the proportions reversed.
But there were limits to their adaptations. Archaeological excavations indicate that the Norse never adopted the harpoons, kayaks, and fishing gear their Inuit neighbors used so successfully. And while there are plenty of seal bones in Norse dumps, virtually no fish bones have been recovered, leading some to argue that they never took advantage of the ample fish resources in the streams and fjords, even in times of famine.
Gisladottir, a native of Iceland, scoffs at the notion, pointing out that Norse in other lands ate fish in quantity. 'Of course they ate fish,' she says. 'One common way of preparing cod was to gut it, dry it, and then cook it in a pot for three or four hours and eat your porridge, bones and all.'
Fish or no fish, the Norse collapse was apparently in slow motion.
Eva Panagiotakopulu, a paleoecologist at the University of Edinburgh, has put together what happened to two of the Norse's more northerly farms with the clues left behind by the flies, lice, and beetles that lived in their sod-walled houses. Although located on the same fjord, she says, the farms met different ends.
Insect species can be highly specialized, allowing scientists to determine what livestock were present (certain lice live only on sheep, others only on goats), whether a building was occupied (some flies could only survive winter inside heated homes), and where food (in the form of decaying meat) was present. Together, their remains provide a record of events on the farms.
Two farms, two different fates
'In one, everything was going fine until the very end, and then they abandoned it, taking their food and supplies with them,' Ms. Panagiotakopulu says. 'In the other, it seems the farmers were trapped in their house during a very long winter, ate their livestock, then their dog, and then died in their beds,' prompting the flies to move from larder to bedroom.
Still, society apparently carried on: Somebody later removed and presumably buried the farmers' bodies.
Other sites also show an orderly abandonment, not an apocalyptic end.
'You don't find bodies in and around the ruins,' says William Fitzhugh, director of the Arctic Studies Center at the Smithsonian Institution in Washington. 'People are being properly buried in church graveyards right up into the 15th century, so it doesn't look like they were wiped out by marauding Inuit or other big disruptions.'
The Greenland Theory
Another indication of an orderly retreat: no valuables such as crucifixes, chalices, or chandeliers at church sites, items often found in early medieval churches elsewhere in Scandinavia.
'Nothing has ever been found of any real value, just everyday items,' says forensic anthropologist Lynnerup. 'To me that indicates they left over an extended period.'
![Greenland Greenland](/uploads/1/1/8/2/118217905/630344504.png)
Dr. Lynnerup's genetic studies of modern Inuit from across Greenland has put another theory to rest: that the Inuit absorbed the Norse. Their mitochondrial DNA (inherited from mothers only) show no European admixture. Archaeological evidence at medieval Inuit sites backs this up, suggesting contact between the two peoples was limited to minor barter.
'During the same time period, a lot of Norse settlements in Iceland and northern Norway were being abandoned, but nobody writes big books about that,' Lynnerup says. 'I'm not sure that the Norse saw Greenland as being very different from the fjords they came from in Norway, and leaving it was no more stressful than abandoning a hamlet in Norway.' His theory: In the 1300s and 1400s, Greenland's youths voted with their feet, leaving until the colony could no longer support itself. The last few left.
'I imagine this old Norse man standing in his sodden, graying field with a couple of scrawny cattle and saying to his son, 'One day, this will all be yours,' ' he says. 'And the son gets on the next ship to Reykjavik.'