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Not Just
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Without
its water, Lake Superior - or rather the 31,700 square miles (82,100
square kilometres) currently covered by Lake Superior - would not
simply expose a hole in the ground (see the special graphics).
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With the considerable trough just off Minnesota’s North Shore, an empty Lake Superior would simply extend the downward drive experienced from the head of the Gunflint down into Grand Marais, says Tom Johnson, a professor with the Large Lakes Observatory in Duluth. “The Apostle Islands would slide up (from the landscape) sort of like the hills” in other parts of Wisconsin.
One underwater area fascinating to see would be the “peak” of the Superior Shoal, the mountain in the middle of some of the lake’s deepest water. It is said that within 3 miles (4.8 kilometres), the lake depth can change from 1,000 feet to about 20 feet (30 to 6.4 metres), a disastrous trick that the lake plays on maritime traffic. Some 1,000-foot “lakers” have a draft (underwater clearance) of 30 feet, deeper than the shoal’s top. The shoal, not really identified until almost the mid-1900s, is considered the probable cause of many disappeared vessels in Lake Superior.
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Refilling Lake Superior
Just how much effort would it take to refill a lake that lost its 3 quadrillion gallons (11.5 quadrillion litres) of water?It would take slightly more than 1 million years for Wisconsin’s 1,253,000 dairy cows, which each average 2,268 gallons of milk annually, to refill the lake with milk; OR it would take 6.7 billion years of Ontario maple syrup production - at 1,686,000 litres a year - to fill the lake with sweet syrup; OR 1.4 billion years of Michigan-brewed beer sales (about 2,073,218 gallons or just more than 66,000 barrels annually); OR it would take 17.8 billion years of Minnesota’s annual live bait usage - that 168,000 gallons of minnows, shiners, chubs and rosy reds a year - to refill the lake with bait fish. Ewww. Better to stick with 3 quadrillion gallons of fresh water! |
With the water gone from the lake, other concerns would surface, say area experts. Greg Zimmerman, chairman of the St. Marys River Binational Public Advisory Council, says that contaminated soils along the edges of the lake may become exposed from erosion without water or new sediment settling on them. Lake Superior has seven “areas of concern” identified under the binational Great Lakes Water Quality Agreement.
“All those PCBs and heavy metals and other organics would be exposed,” Greg says, adding that he would feel keenly the lost of the St. Marys River, which he calls “one of the most fantastic” waterways.
Greg is also chairman of biological sciences at Lake Superior State University in Sault Ste. Marie, Michigan. When asked what might happen if Lake Superior disappeared, he immediately thought of the precious few wetlands around the basin of a lake that often has tall basalt cliffs for its shores. “You can’t have coastal marshes on a steep bank,” he says. Coastal marshes are essential fish habitat, but that, of course, would not be a consideration when there is no lake for the fish. Lake Superior, by the way, is home to about 80 fish species, some of which - like lake trout and the introduced salmon varieties - may not exist in our region without the Big Lake.
Without Lake Superior and its temperature-moderating influence, there also are some birds and mammals that would either no longer call this region home or have many fewer numbers.
“Ducks, geese, bitterns, rails, a host of bird species would be lost,” says Jerry Niemi, a biology professor with the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth. He thinks there would be fewer water-drawn critters, such as frogs and other amphibians, or mammals, such as muskrats. “The big issue would be wetlands,” he adds. “Elimination of the water would be absolutely devastating.”
 It’s
fine to speculate about a world without its largest inland sea, but
thank goodness we can look out - here near the Temperance River State
Park in Minnesota - and be reassured that Lake Superior and its water are
still gracing our neighborhood. Photo by Larry & Linda Dunlap |
Areas around Lake Superior have long been a birder’s paradise because the need to fly around the big water funnels migrating birds to key points such as Hawk Ridge in Minnesota, Thunder Cape in Ontario and Whitefish Point in Michigan.
“You’re a bird and you’ve made a long trip up from Panama,” says Marc Snyder, chairman of the Whitefish Point Bird Observatory board, explaining the funneling. “Then all of a sudden ‘Boom!’ there’s 50 to 60 miles of open water. You either bear right or bear left. … If the lake weren’t there, you wouldn’t see this concentrating effect.”
Some birds, such as ducks content on inland lakes, would remain, but shore species, such as piping plovers and sandpipers, would leave.
Many large mammals - moose, deer, wolves, bear - would still find a comfortable home without Lake Superior.
What grows in the land left behind after the waters might change; as would what crops we as humans can grow, says George Host, a forest ecologist with NRRI. Thanks to the lake, there is a longer frost-free period near its influence.
“It’s this mediating effect from the lake; that warmer zone would disappear. … It would affect vegetable gardens … it would be tough on the apple crop. That whole industry would disappear.”
Because we are already at the northern edge for sugar maple trees, they might also be reduced over time. Our brilliant falls would be less brilliant and shorter.
What might seed the opened lands in the center of the dried-up lake? George suggests aspens, with free-flying seeds, and birch might get early footholds. “Vegetation would sort of creep into the lake; it would be starting over again.”
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