Thucydides on the Lake
Glenn, MI
June 9, 2020
Blaise Pascal surmised that “All men’s miseries derive from not being able to sit in a quiet room alone.” We are spending more time in open air than in quiet rooms, but agree a constant quest for action can be destructive.
So can Lake Michigan.
Winter and waves destroyed the bottom portion of the stairs that carry us from the bluff to the beach. The neighbor’s steps were almost completely obliterated, so we exchange regular greetings with them while we share the planks George and Molly recently repaired.
As we walk along the beach, we see several decks…and some homes…clinging for life on the fragile cusp (or over the fading edge) of failing cliffs. As on the hills of Malibu, behind the levees of Louisiana, or in the sands of the Outer Banks, human hubris is being tested.
In our (geologically meaningless) twenty years watching Lake Michigan, this is as high as we’ve seen it. Apparently, we are emerging from a low-water period, with 2013 marking the recent nadir. Levels are up about six feet since, approaching the heights attained in the mid-1980s. But they have been much higher in the past.
Tectonic separation and glacial retreat formed and filled the basin that now extends to our western horizon. Almost 15,000 years ago (another geologic blip), the ice receded, pushing and carving great moraines that bound the new lake while dozing the great dunes that cover its southeastern shores.
As the ice continued to pull back, outlets formed to the north, draining the basin and lowering the lake. Then, like Ottoman Turks to the Viennese gates, the glaciers made one final push. This assault closed the outlets, raised the lake, and pushed the southern shore miles inland from where idle mills now rust along the Gary coast.
But the advance was doomed. About 10,000 years ago, the glaciers surrendered, pulled back, and cleared a path along the St Lawrence for superfluous water to leave the lakes. The water-level fell perhaps 100 feet below where it is today. The defeated glaciers never returned.
At least not yet. They have a considerable advantage and an abundant resource: time. And they are biding it. They can wait us out before they push us out. As they do, aquatic scouts have launched periodic waves of reconnaissance to and from the basin their glacial ancestors once held.
Over the subsequent five millennia, removal of glacial weight caused the underlying crust to rise. This isostatic rebound raised drainage outlets to the north, and forced flow southward to re-fill the lake.
Cooling temperatures also contributed to rising water, as the lake level is (all else equal) a mirror image of ambient temperature. High temperatures accompany reduced rainfall, and increase evaporation. After the warm mid-Holocene Hypsithermal period, precipitation likely rose, bringing lake levels with it as temperatures and evaporation fell.
Now, water is again on the ascendant.
Yesterday, Rita and David were in Saugatuck, where the marina, as it was last year, is overflowing into peripheral parking areas. The high water does not intimidate our younger son. Nor does its 53 degree temperature. Upon returning home, in almost a ceremonial rite (of lunacy?), he rushed headlong in, dunked himself under, and quickly returned…numb…to the shore, and his senses.
Even at more accommodating temperatures, he could not have swum to spots we used to easily reach.
At what was once about fifty yards from shore, like a tiny Gibraltar guarding Glenn, a lone rock had long pierced the surface of the lake, acting as a benchmark along the beach.
It also was a destination. Each year, often each day, I’d swim with the boys “to the rock”, where we’d plant our figurative flag atop our conquered domain, and survey our aquatic realm. Some years, we could almost walk to it, storming the bastion like the British reclaiming the Falkland Islands.
No longer. Last year was the first when we saw it submerged every day. When the water was calm, we could still detect the stone’s silhouette under the surface, but only because we knew where to look. On only one occasion were we able to complete our annual amphibious assault. This year, it is even deeper, and much further from shore.
And coastal homes are much closer.
Two and a half millennia ago, the emergence of Athens filled Sparta with a fear that made war inevitable. The Greek historian Thucydides lent his name to the “trap” that ensnares great powers as new ones rise. Unsuspecting residents with homes too near the lake may be about to fall into it.
Some already have. Thucydides advised that it is better to strike a rising foe while it is still relatively weak rather than wait till it has strengthened. That makes superficial sense but, for the more susceptible lakeside structures, it may be too late. Like interwar Germany, the foe has been quietly reinforcing and encroaching, and is now in their laps.
Lake Michigan has been relatively docile in recent years, but every once in a while it tries to reclaim lost territory. Now seems to be one of those times. On one side of the front, waves are swelling. On the other, some seasonal residents pitched their settlements a little too close, and are now called to battle stations.
From the security of a house close enough to watch the fight, but far enough to avoid the cross-fire, we observe from a distance, like picnickers at Manassas. And we admire the humbling power of Mother Nature.
This lake is never weak, but it can play possum. And sometimes it bites. Up and down the shore, it’s chewed up embankment stairs, wood bridges, and elevated decks. Over the decades, large homes have sprung up along its bluffs. The last few months, some of them have gotten smaller.
Just up the coast in Pier Cove, houses families have owned and nursed for generations risk collapse…or are being demolished before they do. Fortunately, the houses along our stretch of lake are a ways back from the cliff, and rest safely on secure slopes.
We’re sitting atop one now, catching the breeze and enjoying the view.
But we have moved the chair back a few feet.
Just in case.
JD
