Lake Huron scientists have "Eureka" moment

New discovery in Alpena - Amberley Ridge research

By Josh Howald

Make no mistake, there is treasure at the bottom of Lake Huron. And it is more valuable than you could imagine.

Lake Huron is a Great Lake, indeed, and it is filled with answers. Answers to some incredible questions. Recent discoveries have allowed scientists to begin piecing together the missing years in the history of civilization.

Before we go back 9,000 years, let's just rewind this story to 2009.

Emerson Collegiate Professor Anthropology and Curator of the Great Lakes Museum of Anthropological Archaeology at the University of Michigan, John O'Shea, co-authored a report with Guy Meadows, the Director of Marine Hydrodynamics Laboratories and Professor of Naval Architecture and Atmospheric, Oceanic and Space Sciences, detailing the discovery of archaeological evidence of life beneath Lake Huron. The report describes a ridge that runs from Amberley to Presque Isle, Michigan, USA. The ridge would have once separated Lake Huron into two bodies of water. While most Lake Huron anglers were aware of this shelf, the specifics of it were previously unknown.

The Alplena - Amberley Ridge is sheer rock, and runs uninterrupted as a corridor from Amberley to the United States. It would have been above water 7,500 to 10,000 years ago, with lake levels much lower and a much different climate in the region. It wouldn't have been much different from the Arctic at that period of time, known as the late Paleo-Indian Era. The highest point of this ridge is currently about 38-feet below the surface of Lake Huron, with most of it found between 40 and 120 feet below modern lake levels. O'Shea and Meadows, funded by the United States National Science Foundation, discovered a 350m drive lane of piled stones, thought to have been used by prehistoric hunters to drive animals into ambush.

(Courtesy of Dr. John O'Shea, University of Michigan)

After that discovery in 2009, the research began in earnest. O'Shea's office became an old ocean fishing boat in the middle of Lake Huron. Armed with cameras, the boat has been in the water nearly every day it possibly could have been for the last five years. The University of Michigan based research team started in the middle, and have slowly worked back towards land on the United States side of Lake Huron.

"We've been grinding away each summer," said O'Shea last week. "Then, last summer, we got a new piece of equipment."

The new piece of equipment was a scanning sonar unit. Without it, the latest discovery may have not occurred. Basically, it is an underwater camera suspended on a tripod that has the ability to rotate 360 degrees to help create a precise map of an area. The team was mapping part of the lake where they had previously found some of these hunting structures.

"We found it quite by accident," said O'Shea. "The images appear in real time on a computer on the boat. We had a grad student say 'Wait!' And this incredible image appeared. It was like, hold on! It really was an Eureka! moment for us, something special."

What they found has provided unprecedented insight into the social and seasonal organization of early man in this region. It is a 9,000-year old caribou hunting drive lane, the most complex hunting structure ever found beneath the Great Lakes. It is located directly on the Alpena - Amberley Ridge under 121-feet of water, 35 miles southeast of Alpena, Michigan. Built on level limestone bedrock, the stone lane was built with two lines of stones that lead to a cul-de-sac formed by the natural cobble pavement. Built into these stone lines are three circular hunting blinds, with three more alignments that would have served as blinds and obstructions for corralling caribou.

"Basically, early man would have used the natural landscape of the land to herd them, then hide behind these rocks and wait for caribou. Then toss a spear and eat some supper," explained Dr. Elizabeth Sonnenburg, SSHRC Postdoctoral Fellow at the University of Michigan Museum of Anthropology, and the first Canadian to become involved in this research project.

The discovery came on the 45th time they dropped the new scanning sonar unit into the water. So the structure has been dubbed Drop 45.

Drop 45 has produced numerous flakes of shert, commonly used to make prehistoric tools, unscattered, concentrated in two of the three blinds.

"It tells us people were there, doing these systematic hunts," said O'Shea. "It confirms that these are not just convenient looking glacial features of the landscape."

The discovery of Drop 45 is significant for several reasons. There is a gap in history during the time period that lake levels were that low. Not much is known about the Paleo-Indian stage of the world. One reason is that people tend to always live near the water. This is one of the only sites in the world from this time period that has remained preserved.

"It's almost like Pompeii," said O'Shea, comparing it to the ancient Roman city that was buried under six feet of lava and ash from Mount Vesuvius in 79 A.D., and perfectly preserved because of the lack of air and moisture.

"While these hunting structures very well could have appeared on land, they would have been destroyed over time by settlement, farming, development or whatever," he said. "This is the only place in the world to find these sort of structures that date this far back."

The team has previously found an intact fire pit under Lake Huron. Samples from the charcoal indicate it was, indeed, 9,00 years old.

Drop 45 was discovered in late August, and most resources in August and September were spent acquiring archaeological sampling. Underwater visibility is less than perfect at that time of year, so they weren't able to acquire the images they were hoping too. They were able to see patterns of stone tool debris. The weather, and the ice in particular, put things on hiatus until last week, when they returned to the office. Much of this summer will be spent trying to locate where the settlements would have been. It is a much more difficult task, due to the lack of obvious physical features, "but they should be in the general vicinity, yet well back from the animal routes."

He thinks they have located one, and was chomping at the bit to get back on the water. Thus far, all the scanning has been done on the American side of the ridge - enter Sonnenburg.

Sonnenburg has acquired the necessary exploration permits, as well as funding, to start research on the Canadian side of the Alpena - Amberley Ridge this summer.

"Quite literally, we have only just scratched the surface," said Sonnenburg. "There are so many possibilities. (O'Shea) has a slide show that has a picture of the teeny little square we work at out on the lake. It is labelled 'Humility'."

It would take a lifetime to explore every inch of the bottom of Lake Huron, but the research is not likely to last quite that long, regardless of what is discovered.

"We have current funding for one more season of field work," said O'Shea. "We would obviously like to keep going, but funding is always a priority."

Sonnenburg has funding for the next year. After that, this project is likely to come to an end.

This pattern of hunting dates back to the Neanderthals, O'Shea explained. There may be sites in France and Hungary, he said, but they have been disturbed by man and this is the only spot that remains untouched, underwater.

The original story from June, 2009 can be found on this site. Simply search "Evidence of life beneath Lake Huron".