Measuring Change
I grew up spending time in the Adirondack mountains of upstate New York. The mountains are almost like family to me, and that area more than any other is what I think of as home. Mountain climbing in the Adirondacks is hard. Some of the hikes are very long, and typically you are in the trees much of the way, with mud and rocks and roots to challenge you. Maybe there is a top, or maybe it’s mostly trees with little view and only a small perch. It’s the kind of thing where you really have to enjoy the journey, because it can’t be all about the destination. Needless to say, there is plenty of time to think and, in particular, to think about mountains themselves: what they are, and how we identify them, quantify them, and then set out to conquer them (foolish us!). The wilderness there is not to be taken lightly. Almost every day rangers have to go in and rescue people.
To give you a few facts about the Adirondacks: there are 46 peaks said to be over 4,000 feet—it’s a thing to climb all 46, but according to recent measurements, 4 of those are actually under 4,000 feet. Officially, an individual peak must have 300 feet of distinct prominence from surrounding mountains and/or be at least ¾ mile from the next peak, but at least 3 of the Adirondacks don’t meet that requirement from a height or distance perspective. And, as with all mountains, their heights are measured relative to sea level, though when you are climbing them, all you really care about is the total altitude gained during the hike—in other words, how far up the mountain are you starting, and how much is left to go?
Which brings me to the problem of sea level. In a recent issue of The New Yorker, Brooke Jarvis has an article about sea level that is part book review and part environmental lament. It’s a short article, and it opened my eyes to the problem of sea level, which of course directly relates to the height of mountains.
Jarvis starts her article with the story of Rich Nils, a wealthy seal hunter who lived in Sweden in the mid-1500s. (This is not an odd name—my father’s family can supposedly trace its roots back to a 12th-century Swede named Martin the Wolf Hunter.) There was a rock in the ocean off his property that seals would climb on, thereby allowing him to easily harpoon them—and become rich. After a while, he noticed that the seals couldn’t easily get to the top of the rock, that the sea level was going down. He actually seems to have worked to chip off the highest part so that it was easier for the seals to get to the top, thus perhaps helping him stay rich.
About 200 years later, Anders Celsius, the measurer, found Nils’s rock as he was looking for fixed points that he could use to help measure change. By then, the Baltic Sea had sunk almost 8 feet, and Rich Nils’s rock was becoming part of the mainland. In 2012, another scientist went looking for the rock and found it—this time in a forest.
According to Jarvis, people trying to understand the apparent sinking of the Baltic Sea originally thought it was from the slow draining of the biblical flood waters. But later scientists realized that the sea was “sinking” at different rates in different parts of the Baltic, and therefore concluded that the sea wasn’t sinking—the land was rising. Geologists now call this “postglacial uplift,” as Jarvis writes, “the slow ‘bounce-back’ of land that was long compressed by the great weight of earlier glaciers.” The understanding that the land had risen helped people to assume that sea level was constant, and therefore a good baseline for measuring everything else.
You might be wondering: is sea level a constant, and how hard is it to measure? Well, it turns out to be quite local, a bit arbitrary, and nevertheless generally agreed upon—in other words, a social construct. It is the result of scientists all over the world and many groups, including NASA and the U.S. Navy, who established what is called the International Height Reference System, doing their best to identify some kind of baseline and stick to it. When you dive into this world of sea level, you find scholars writing Ph.D. dissertations on its measurement and the consequences thereof.
And then there is one other physical earth fact to contend with: the earth is not round. Because of how it rotates on its axis and the centrifugal and gravitational forces on it, the earth bulges at the equator. In fact, the earth’s surface at the equator is 22 kilometers farther away from the center of the earth than it is at the poles.
Which brings me back to mountains. Why do we measure them against sea level? Well, I suppose, why not? But if you wanted to be more precise about it, you would need to recognize that sea level is not constant and that there might be other considerations. As an example, Mount Everest is universally considered to be the highest mountain on earth. Its peak is indeed at the highest elevation above sea level. But Mauna Kea in Hawaii is the tallest mountain from its base (which happens to be underwater); and the peak of Mount Chimborazo in Ecuador is actually farthest from Earth’s center. But Chimborazo is only the 39th highest mountain in the Andes range, as measured by sea level.
I wish this meant that I could reinterpret measurements and claim some exalted status for my beloved Adirondack mountains but in fact they are still only 4,000 feet above sea level, while Chimborazo is over 20,000 and Everest is over 29,000. But I now think about them a bit differently, and see the landscape with slightly new eyes.
And, so, what might we conclude from this sea level discussion? Well, a couple of things, to my mind. My godson suggested that this means everyone can have their own personal sea level. Well, no, not really. There really is such a thing as sea level, despite its being a social construct (or perhaps because of that), and it’s important for us to realize that we humans do determine and agree upon facts. But those facts are not permanent, and our understanding of sea level seems likely to shift as well—though perhaps not in our lifetimes. I guess we can hope for that.
My other conclusion is the one that is more important to me as we begin a new school year: we, those of us who work in schools, who are dedicated to the education of young people and committed to making the world a better place through our careers—we are all captivated by learning, by the newest thing we can think about or discover, by a life where worlds open up to us all the time. We are dedicated to it for ourselves and our students. We teachers revise our classes each year because of this passion for learning, and because of our belief that education is a profound force for good in this strange unmeasurable world. Indeed, we might even think that this is a fundamental reason for living: to learn as much as we can, to expand our horizons and those of the people around us. Knowing more makes us better stewards, more thoughtful caretakers of this incredible planet and of the beautiful people we inhabit it with.
It is a blessing to be part of the Winsor community, to enjoy the challenges and triumphs of each new school year, to be fascinated by learning that sea level is not what we thought, to be lucky enough to see that the world has several “tallest” mountains. May this school year be rich with such discoveries and perspectives.
