Going the Full Circle: A walk around Post-Glacial Lake Superior
04.11.2010, 1:39 pm
Filed under: Uncategorized

NASA image, MODIS Rapid Response Team

The countdown on their blog reads “18 days.”  On April 29, 2010 Mike Link (executive director of the Audubon Center of the North Woods near Sandstone, MN, since its founding in 1971) and naturalist/writer Kate Crowley, will step off on their “Full Circle” Expedition–an approximately 1800 mile walk around Lake Superior.  In a five month long supported expedition, the wife and husband team will hike and sometimes canoe as close to the shoreline of the Lake as possible.  Their data collection will create an unprecedented portrait of the ecology of the shoreline, the people and places they encounter, the streams they cross, and the lifestyle they describe as “focused nomads.”

FOP interviewed Mike on the eve of their adventure, which will take them to a landscape that started to form 1.1 billion years ago when North America began to split apart, creating a 1243 mile long rift at its center.  The rift stretched from Michigan west across Wisconsin and on to Minnesota, Iowa, Nebraska, and the north east tip of Kansas.

Mike and Kate will be walking a circle in the northernmost arc of this great rift.

The Mid-1980s View of the Extent of the Mid-Continent Rift (after Van Schmus and Hinze 1985), Based Soley on Gravity and Magnetic Data

The Midcontinent Rift is the deepest known rift in the world–up to 19 miles deep in places.  For 20 million years, lava flowed up through it.  If the rift had continued to grow, it would have torn North America in half and allowed the sea to rush in, turning America’s “heartland” into an ocean.

But the rift closed and the lava retreated.  Its bedrock sank and created a basin that is nearly 50,000 square miles in size.  About two million years ago glacial ice began to sculpt the basin into its present shape. At the end of the last ice age, 10,000 years ago, the meltwaters gathered at the edge of glaciers that were 1.24 miles thick, forming Pleistocene Lakes Duluth (in the west) and Minong (in the east).  The ice retreated, and about 2100 years ago, the earth’s crust began to rebound after being pushed downward by the glaciers.  As the surface rose, the Pleistocene lakes separated into Lakes Superior, Huron and Michigan.  An outlet from Lake Superior to Lake Huron was established through the St. Mary’s River, and as the water level fell, the shape and size of the lake we know today as Lake Superior appeared.

Lake Superior during the Pleistocene, from the 1911 USGS Monograph, Geology of the Lake Superior Region

Lake Superior (and surrounding area) under lobes of glaciation, from the 1911 USGS Monograph, Geology of the Lake Superior Region

And it’s the water of Lake Superior, which amounts to no less than ten percent of the fresh water on the surface of the entire planet, that has inspired Mike and Kate’s Full Circle Expedition.

Mike Link:

The emphasis on our trip is on fresh water and the Great Lakes.  I’ve been a college professor for a long time teaching about field studies that linked biology and geology together.  I’m not sure you can do anything that doesn’t have a geologic link to it.  I don’t know where you start if you don’t start from geology.  We are looking at a really unique geological landform here that is in fact the only geologic landform visible from the moon.

When you’re looking at this little blue planet you can see continents, you can see oceans, and there’s only one thing on the continents that shows up from all those satellite photos and that’s the Great Lakes. And yet because they’re so large we tend to take them for granted.  It’s almost as if they’re too large to be damaged.  But we all know that’s not true.  They’re a very young formation which people call post-glacial.  Lake Superior has one tenth of the fresh water on the surface of the earth and the Great Lakes has 20 percent of the fresh water on the surface of the earth. Now in a world in which biological life cannot exist without air or water it’s pretty hard for me not to see those as some of the most absolute essential resources that we have.  And so that’s in a nutshell.

Kate and I want to do one more thing to raise awareness.  It’s kind of like geologic history–you can talk about four and half billion years but you only get to see 100 of them.  And sometimes it’s hard to expand from your small vision to encapsulate the large.

When Mike and Kate started to plan their expedition, incredibly, they couldn’t find the answer to the most basic question:  just how long would they have to walk to make a full circle of Lake Superior?


When we went on the web to find out how far we were walking, we came up with everything from 1350 to 2925 miles.  We actually found resources that went that spectrum and most of them were somewhere in between.  Which said to us they actually really don’t know.  We won’t know completely either because we can’t walk out to the point of every bay.  We can’t do that.  But we’re going to have a pretty good sense of the circumference of the lake and that will be pretty interesting.

Establishing a baseline is a key to what we’re trying to do on two different levels. Kate came up with the principle anchoring work project that we’re doing.  Every three miles we would stop take a breather.  And she said if we’re going to do that, let’s take photographs in each of the cardinal directions and then take notes on the vegetation and any other observations that we make.  When we stitch that all together we will have 500-600 locations around Lake Superior with this baseline data, this dot-to-dot connection. And so in the future when people come and say: “Well the lake has changed or hasn’t changed,”  instead of it just being word of mouth or memory there will actually be a GPS point and data source that people can go to and say:  “Well look, it has changed because look here, take a comparative photo.”

Gordon Bushaw and Mark Klett, Castle Rock, Green River, Wyoming, 1979.
Rephotograph of Timothy H. O’Sullivan, Green River Buttes, Green River, Wyoming, 1872.
© The Rephotographic Survey Project, 1979.

We asked Mike about the role of aesthetic experience in their project–do they consider the baseline photos they plan to take to be an aesthetic act, or documentation?  Might there be some resonance between their baseline photo project and Mark Klett’s rephotography project, in which he rephotographed, as part of his art practice, scenes of the American West first taken by scientists as part of their geologic surveys?


Art has always been a means by which we capture and relate the importance of a resource.   The artist helps us get a sense of feeling of place.  I would love to see our photographs used in that way as well.

We’re going to combine the aesthetic and the documentary.  There will be work that is done simply for documentary photography and also there will aesthetic photography.  There will be work that’s done simply for the art of the moment and place, and other photos that will be for scientific baseline.  And those photos may on occasion be artistic but we’re going to take them regardless of time of day, of sun location and subject matter.

Art is an important language that we don’t give emphasis to as scientists.  I think I am one of the exceptions.  I don’t see the interface between artists and scientists going both ways as much as I would like it to.  Part of that is the restriction of science itself, and the restrictions that scientists put on themselves:  to be this unfeeling neutral body who just collects facts and data.  At one time there were artists who would go with naturalists on various expeditions and you would require both of them to get the story about what was discovered and named and observed.  We’re not as aware of that right now as we should be.

The photos we take will be records, the same way we’ll be taking records of the stream loads so that we can establish the relationship of stream outflow to lake level.  We hope that we will have records that will help protect the lake from draw down that everybody from Arizona to the other Great Lakes wants to do.

In 2005, the states of Minnesota, Wisconsin, Illinois, Indiana, Ohio, Michigan, Pennsylvania and New York, and the premiers of the Canadian provinces of Quebec and Ontario signed the Great Lakes Water Resources Compact.  It controls who can use the water and how much and it was adopted after a Canadian company “proposed shipping water in tankers from Lake Ontario to Asia. Other proposals had been floated over the years about piping Great Lakes water to Arizona, western Canada or elsewhere.” (USAToday)

Pigeon Point, an edge of Lake Superior from the 1911 USGS Monograph, Geology of the Lake Superior Region

While FOP was preparing for our interview with Mike, we discovered that Charles Van Hise, who together with C. K. Leith accomplished the first comprehensive survey of the Lake Superior region (“The Geology of the Lake Superior Region,” Mono-graph LII, U. S. Geological Survey, 1911), shared FOP’s interest in expanding human imaginations into deep time.  Van Hise wrote the following while President of the University of Wisconsin:

How long shall this nation endure? Or, more exactly, how long shall human beings occupy this land? . . . We should think, not of a hundred years, or of a thousand years, but of hundreds of thousands, or of millions of years of development of the human race. There is no reason, from a geological point of view, why human beings may not live upon this earth for millions of years to come, perhaps many millions of years, and, so far as we are concerned, such periods are practically infinite.

These considerations impose upon us as our most fundamental duty the transmission of the heritage of our natural resources to our descendants as nearly intact as possible. This is an individual responsibility, as well as a state and a national responsibility.There’s a strongly developed opinion at the present time that the owners of great wealth, and especially those who control great natural resources, should act as trustees for the nation.”

detail from from the 1911 USGS Monograph, Geology of the Lake Superior Region

Mike said that deep time does factor into their work:

I think that deep time is behind our understanding of the Lake.  But I don’t know that that is going to be as much a part of our message.  Even thought I think it’s important to encourage people to understand the formation of the Lake and the rocks and the history of the earth.  What I think is important to me now is we need to create a sense of place and understanding of where you are with a sense of responsibility for the immediately future generations.  . . .If we can get people to do that and think in the broader human time, then perhaps we can get people to start to think in a more dramatic way about the larger earth span and our small amount of time on it and the huge impact we have on it in that time.

As we walk around the lake and give programs,  one of the things that we initially need to do is to expand people’s minds around the space continuum rather than through time.  We need to get people in Marquette to be concerned about what happens in Munising, MI and people in Sault St. Marie concerned about what happens in Thunder Bay and realize that they’re all connected.

FOP follow Mike and Kate’s walk around Lake Superior closely. And we’re honored that they’ve accepted our invitation to collaborate with FOP and send us provocations from the shoreline of post-glacial Lake Superior.  We’ll offer creative responses to the data and research insights that they share with us, and post the results here.  Best of luck to them both as they embark on the 29th!

You can read dispatches from their trip here.  And you can become a fan of the project on Facebook here.

2 Comments so far
Leave a comment

what is their itinerary?

Comment by anesthesiahist

you can learn more about the specifics of their itinerary on the full circle website, here’s a link to the route:

Comment by FOP

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