The asthenosphere, as described in Brian Kevin’s Yellowstone and Grand Tetons National Parks guide (Bookshop|Amazon) is a gurgling sea of plasticized rock beneath the earth’s rocky crust. Asthenosphere derives from Greek asthenes, meaning “weak” or “feeble,” and a relative of the English words for “muscle weakness,” myasthenia, and “nerve weakness,” neurasthenia. The Greek word for “strong,” sthenos, gives us the English word calisthenics, or “beautiful strength,” a form of exercise originally designed primarily to promote strength and fitness in girls. These rhythmic exercises were popularized in the 19th century by the sister of Harriet Beecher Stowe, author of Uncle Tom’s Cabin (Bookshop|Amazon). This is part of a complete episode.
Transcript of “The Asthenosphere”
You’re listening to A Way with Words, the show about language and how we use it. I’m Grant Barrett.
And I’m Martha Barnette. My spouse and I decided we really needed a change of scenery, so last month we took a long road trip to Montana to do some hiking, which of course was glorious. We also visited Yellowstone National Park, and we took a couple of guidebooks with us, and I wanted to share a bit of writing from one of them. It’s by Brian Kevin, and it’s called simply Yellowstone and Grand Teton National Parks. He’s describing the geological features that make Yellowstone so distinctive with its hot springs and spewing geysers, and it’s a nice piece of writing that offers a big picture perspective, and it sent me down some cool etymological paths. He writes,
The first thing to remember is that we’re all floating, all of us, all the time. We’re adrift on huge continental islands or plates that comprise the planet’s uppermost 50 to 80 miles, known to geologists as the lithosphere. These lithospheric plates drift around on a gurgling sea of plasticized rock called the asthenosphere, bumping and grinding and occasionally sliding beneath one another at a rate of an inch or two every year. Another 1,500 miles below the asthenosphere, much deeper into the layer known as the lower mantle, the rock goes from plasticized to out-and-out molten. Gobs of this molten rock occasionally get so hot that they have to ascend, like the lava in a lava lamp, and they do so in long, narrow plumes running upward through the mantle. When these molten plumes hit the bottom of a solid lithospheric plate, they flatten out into the wide molten pools we call hotspots.
And Grant, that’s a great explanation of this huge area that underlies Yellowstone National Park. But a couple of words caught my ear, one of which, as you might imagine, is lithosphere, which means the rocky outer part of the earth. That’s from Greek lithos, meaning stone or rock, just as a monolith is literally a single block of stone. But the word that really stopped me short was asthenosphere. That’s A-S-T-H-E-N-O sphere. And it comes from the Greek word asthenes, which means weak or feeble. And that means it’s related to words like myasthenia, which is muscle weakness, or neurasthenia, which is fatigue and malaise that originally was thought to be caused by weak nerves.
But I was thinking, could the part below the Earth’s rocky crust really be named from the Greek word for weakness? And it turns out, yes. The asthenosphere is literally the sphere of weakness. It’s made up of, as one dictionary put it, material believed to yield readily to persistent stresses. It’s much hotter and more fluid than the hard, rocky lithosphere. So I was all excited, of course, as you can imagine, to learn this new word, asthenosphere. And then I made another connection, because in Greek, asthenes, or weakness, literally means without strength. And the root word of that is sthenos, which means strength. And that got me to thinking about where we might find a derivative of sthenos, S-T-H-E-N-O-S, in English. And we do have one. Can you guess what it is? Aesthetics? Or I don’t know. The word strength itself. I don’t know. Well, it has to do with strength. It’s the word calisthenics, the word for exercise. It comes from Greek words that mean literally beautiful strength. And as the OED puts it, calisthenics are light, systematic, rhythmic exercises designed to achieve physical fitness alongside grace of movement, especially intended for women or girls.
And that sent me to looking for the origin of why we use this word. And it turns out that calisthenics was popularized in the 19th century by Catherine Esther Beecher, an advocate of education for young women, along with her sister, Harriet Beecher Stowe. So there you go, Grant. This is how my mind works all the time from the rocky crust of the earth to the author of Uncle Tom’s Cabin in five easy etymological steps.
So you are in Yellowstone, a beautiful place, reading a beautiful passage about this beautiful earth. You’re reading about the layers of the earth and you find layers of language.
That is completely you, Martha. That’s wonderful. Thank you so much for this. This is delightful. I’m so happy that you shared this with us. This is fantastic. Thank you for indulging me, Grant. I think, yeah, my mind is kind of this fiery mountain mass. You just let me know. I’ll turn on the mics for you.
Oh, and I know that our listeners are big readers, particularly with the pandemic. People have been pulling those must-read books that have been getting a little dusty off their shelves and off their bedside tables and giving them a chance. Share your best passages with us. Share those connections that you made. Share those layers with us. We’d love to hear them and share them with everyone else. 877-929-9673. Email the passage to us at words@waywordradio.org or take a screenshot and send it to us on Twitter @wayword.
