March 2, 2020

FTV: Time and Tide Part 2

     In Part 1 of Time and Tide, we examined some of the ways humans have managed to foul up Mother Nature’s handiwork.  Specifically, we looked at the mess humans caused by adjusting natural beach patterns in Bayocean, Oregon, Grand Marais, Michigan, and the Lakeshore Boulevard beach front in Marquette, Michigan.  In this segment, we will examine the problems that are occuring along the Ontonagon coast.

     Before we get too deep into the problems and proposed solutions to the current lakeshore difficulties in this area, we need to take a brief look at the dynamics of Lake Superior.  As the last continental glaciers retreated, what we now know as Lake Superior was formed over a 10,000 to 20,000 year period. The first hint of the lake appeared in the western part of the basin and grew as the glacier front melted eastward.  When Ontonagon County was first ice free, the earliest south shore of Lake Superior was along the moraines south of Bruce Crossing. A morain is a long hill formed as a glacial ice sheet moves forward at the same rate that it is melting back. The glacier acts like an upside down conveyor belt that moves material at its base to the glacial front where it is piled up into hills that mark the ice margin. The longer the ice remains in this mode, the higher the hills become.   By tracing the moraines and meltwater drainage patterns left behind, we can reconstruct these early lake stages that were formed and shaped long ago. In its earliest iteration, Lake Superior formed behind the Covington moraine, leaving the current shoreline of the lake under some 600 feet of water. The hills above Rockland and Mass City-Greenland were offshore islands (accounting for the beach- like sediments that can be found at various levels around those lines of hills).

     The historical shapes of Lake Superior can still be mapped by the successively lower shorelines imprinted on the hills from the tip of the Keweenaw Peninsula to the Porcupine Mountains.  Over some 8,000 years, the Superior shoreline retreated to lower and lower levels. Around Mass City, Rockland, and in the Porcupine Mountains, each lower beach stage can be seen in the ancient beach ridges that were formed (the beach-like sediments previously mentioned).  It is no surprise that the sand flats between Rousseau and Bob Lake resemble the sediments one finds on the current Superior beaches. Each time the lake level dropped, a new set of beach ridges were formed by wave action piling up these sediments. Interestingly enough, the rings of ancient miner’s pits found above Rockland, Mass City, and Greenland also mark the changing lake levels.  When the ancient miners first discovered and mined Upper Michigan copper, they were working deposits that were easily discovered on these bare rock islands jutting out of the early lake. By the time these islands took their present form (seen today as the bluffs connecting Rockland and Mass City), the local lakeshore had retreated nearly a mile north of the present shoreline. This period marked the lowest Lake Superior level in the recent past.

     Crustal rebound eventually closed off the lowest outlet draining the upper lake via the Ottawa River through a gorge at North Bay, Ontario.  During this period with no outlet, the lake levels began to rise until they hit the highest level in the past 2000 years. The shoreline created by this last high lake level can be seen in Ontonagon as the winding hill that cuts through town from the Village Recreation building, past the Township Library and the hill connecting River Street to the Greenland Road near the Methodist church.  As one drives west toward Silver City, the homes built on the rise to the south all occupy the top of this ancient Nippising Lake Stage beach. When the modern lake outlet through the St. Mary’s River at Sault Ste. Marie was established, the modern lakeshore was set and the average Lake Superior elevation settled at 602 feet above sea level, more or less.

     Why more or less?  The ‘long term average surface elevation’ of Lake Superior is listed at 602 feet above sea level, but in the last fifty years, it has been as low as 599.48 feet and as high as 603.38 feet.  In 2007, when the previous 1926 all time low was briefly eclipsed, water enthusiasts and lake shippers alike sounded the alarm. The experts looked into their crystal balls and assured everyone that the lake would rebound in a decade or so, as soon as the annual precipitation returned to normal.  Boy, did they miss that prediction by a mile!

     On the heels of the low lake levels caused by a long period of drought conditions came a period of unrelenting snow and rain.  The ‘decade’ predicted to get the Lake Superior back to the long term average ended up to be a mere four years. Ironically, the combination of increased precipitation and lowered evaporation (cold winters with more ice coverage slow the loss of lake water to the atmosphere) caused Lake Superior to keep rising.  If the extremely low lake levels made everyone worry, the high levels we are now experiencing are proving to be even more worrisome.

     In Part 1, we told the story of the relocation project currently being planned for Lakeshore Boulevard in Marquette.  The segment of this street has been plagued with numerous closures due to high lake level wave action tossing tons of water and actual boulders onto the roadway.  The boulders are being ripped from the armouring that was put in place to protect the road. The road needed protection because the Presque Isle breakwater extension installed in 1940 changed the angle that waves attack the shoreline.  If left alone, Mother Nature would have resculpted that shoreline into a graceful, stable curve that would dissipate wave energy. Adding tons of rip-rap boulders protected Lakeshore Boulevard for many years, but also contributed to how ferociously the high lake level waves interact with the shore.  If this is beginning to sound a bit familiar, you may be or know a lakeshore property owner.

     The rising lake level has been a growing concern for everyone who owns beach front property in Ontonagon County.  Some have had to resort to moving outbuildings (and homes in some cases) as the waves consume more and more of their property.  Some have been forced to armour their own shorelines with rip-rap, but as previously mentioned, this is at best a stop gap solution.  Should the lake level remain high (or keep rising), Mother Nature will continue to carve away the old beach ridges until she has reached the equilibrium of a graceful, wave absorbing curve.

     Ontonagon County and the State of Michigan are now working on a solution to protect the stretch of County Road 107 along Union Bay.  Perhaps you have seen the pictures in the local papers: rock armouring has been laid in places to try and protect the main entry way to the Porcupine Mountain Wilderness State Park.  There were informational meetings held in 2019 to discuss several options to mitigate the CR 107 problem. As always, there are solutions that will cost more and there are those that will cost less.  If we wish to address the continued high lake levels, then we must be prepared to spend the money necessary for a long term solution to this problem. Protecting the road in its current location will be less costly up front, how long will this short term solution work?  When Mother Nature wins the battle, we will end up paying twice to fix the problem. Armouring wave washed stretches to protect the road is a short term solution that will only delay the inevitable. It is understandable that the bridge over the Mineral River would be extremely costly to relocate upstream, but it shouldn’t be taken off the table if long term access to the Porkies is in jeopardy.

     The smart money here says, “Let Mother Nature win.  Let the lake resculpt the lake front along CR 107 into a more stable configuration.  It is time to abandon this section of roadway and relocate the main entry to the Porkies inland.  Again, it could be moved a shorter distance at a lower cost, but it needs to be done the right way so it won’t have to be done again.  The most expensive plan would require a much wider set back for the road, but as one would expect, the cost makes this a very unpopular move.  Some have said, “We must maintain the beautiful view of Lake Superior that tourists see driving into the park.” Remember the Lakeshore Boulevard problem in Marquette?  The ‘beautiful view of the lake’ from the armoured section of the roadway is that of a pile of rocks that obscures any view of the lake along that stretch of road. Marquette is pursuing the right course:  relocation of the roadway far enough inland that it won’t require extensive mounds of rocks for protection. They will engineer a lower profile protected shoreline that will help Mother Nature stabilize things, but they won’t face moving Lakeshore Boulevard again.

     One of the high lake topics that comes up repeatedly concerns how much control over the Lake Superior level is exerted by the Corps of Engineers operations at the Soo Locks.  With a new lock being discussed at the time of this writing, it will no doubt come up again. The Corps of Engineers does not have a magical structure in place on the Saint Mary’s River that they are using to maintain the high lake levels.  If the Corps had that much control, then they could have averted the problems everyone had with the extremely low lake level. In truth, the long term fluctuations of Lake Superior (and the other Great Lakes for that matter), are a complex combination of factors.  These fluctuations have been taking place since the first Native American and European explorers paddled these waters. What effect global warming will have on them in the future is still up in the air. The lakes will do their thing and it is only a problem when we humans think that we can control enough of the variables to bend it to our will.  As they say in many a good gangster flick, “Ain’t gonna happen!”

     Here is one theory about the effect global warming may have on Lake Superior.  With the wolf population on Isle Royale in peril, the Park Service has begun a program of relocating new wolves to the island.  Without fresh sets of genes in the reproductive pool, the population has crashed. Without predatory wolves to cull the moose herd, there is a danger that the island’s ecosystems could be disrupted by overgrazing.  Before the wolf transplants were begun, the only other way for new animals to find their way to the island was over an ice bridge from Canada. In one scenario, global warming may prevent complete ice bridges to the island in the future and thus remove a natural way for the wolves to repopulate Isle Royale.  After a long period devoted to studying the wolf-moose relationship on Isle Royale, the Park Service decided the best way to improve the wolf gene pool was to import new animals. It isn’t a new problem, but if the occasional ice bridges do not form in the future as some predict, it will become the only alternative to keeping things in balance on Isle Royale.  There has been some talk of late about allowing a moose culling special hunting season at some point, but this is unlikely to happen if the Park Service follows their normal procedures governing this sort of problem.

     The one thing that nobody has mentioned yet is the effect of global warming on the lake levels.  If the lake does not freeze over completely, more water will evaporate from the surface. It would not be enough to offset the total rise, but when people are grasping at straws for any good news, some are sure to think that this would be a good thing.  I believe the negative impact of letting global warming continue unabated would not be a positive outcome for planet Earth in the long run. We have seen that humankind can make a difference when a climate crisis is at hand (look up the ‘Battle for the Ozone layer’ that was waged against the gases used in spray cans several decades ago).  It is time that we make a commitment to doing more than lip service about the issue of global warming. ‘Denial’ is indeed a river in Egypt and not a realistic examination of the data we already have collected about global warming.

     As for the fight between Mother Nature and those with lakeshore property being threatened by the current high lake levels – stay tuned.  The one thing we need to remember is simply ‘Mother Nature can be held a bay only so long before she gets her way – not only is it not right to ‘fight’ Mother Nature, it is a fool’s errand.

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