Plate Tectonics and a sixteenth birthday.
We have experienced more than a few earthquakes since moving here. A few weeks ago, my daughters were sitting on the beach while the rest of us were bouncing around in the waves of the ocean. They run to the water and ask if we felt it and of course, no we didn’t because we were afloat. We did feel the one that shook the car while it was parked. I was about to scold the kids for jumping around in the back and then I turned and saw everyone sitting still with eyes wide open.
I covered a unit on Plate Tectonics with my teen group.
The driving question that set the tone for the unit was
“How do theories become generally accepted?”
Plate Tectonics to Geology is what the Theory of Evolution is to Biology but it was initially proposed by Alfred Wegener. Although he had evidence, this theory was only accepted after fifty years when others could corroborate it.
He wasn’t a geologist which is why it took so long to become accepted. He was an astronomer and a meteorologist who loved to fly hot-air balloons. He also refused to see boundaries between disciplines.
His natural curiosity for the world allowed him to look at a map one day and
noticed the east coast of South America fits exactly against the west coast of Africa, as if they had once been joined. He looked for further evidence, found it, and, in 1915, published The Origin of Continents and Oceans. In it, he claimed that about 300 million years ago, the continents formed a single mass that he labeled ‘Pangaea,’a Greek word meaning ‘whole Earth.’
- Bill Bryson, A Short History of Nearly Everything
He also used other types of evidence – the fossil record, similar geographic features of land masses that were in different parts of the world that may have been part of one mass at another point in time, and he even proposed that’s how mountains were formed – when the edges of continents drifted together and collided and folded instead of the prevailing theory that the land simply wrinkled like a rotting apple.
Wegener announced his findings at a Geology Conference and was promptly ridiculed. He sat smoking his pipe and listened to his critics. He died before Harry Hammond Hess, a geologist who found himself commandeering a submarine in WWII, was able to use the sub’s sounding gear to “see” what the ocean floor actually looked like. His theory of “seafloor spreading,” easily proven through ocean-core samples, completed matched with the Wegener’s theory of plate tectonics.
Now plate tectonics is an accepted theory and the history of earth and its movements can be written more clearly.
The world, literally, does not stop shifting. “We are all Lava Surfers,” an article written by Peter Stark, a travel adventurer, tells of earth’s violent history and its continuing volatility beneath the surface. Our brain “floats” in cerebral fluid under a protective skull just like our earth’s plates move due to mantle currents in hot lava beneath the crust.
Stability is an illusion. The teens loved the article. We talked about the relevance of political borders in terms of the longer timeline of our earth’s rock records. One thing is certain, the geography of the land will change.
My daughter turns sixteen today. Adolescence is all about movement and volatility (which is why I teach plate tectonics at 15-16.) As she took notes while I lectured about the Earth’s movements above and beneath the surface, she turned the pages furiously in another notebook, obviously searching for something.
She says, “Mama, I have the perfect quote.”
She reads it out loud. It is from one of her favourite books that she wrote down a year ago.
Earthquakes are the consequences of tensions built up over long spans of time, imperceptibly, incrementally. You don’t notice the build up just the release. – Rebecca Solnit, The Faraway Nearby
Happy birthday my sweet girl. You are surfing the ocean of adolescence with grace and with just the right amount of fire.
- Copy the above quote or the poem below.
- Draw a map that moves.
- What if feeling “grounded” is an illusion because the land shifts? Are there more places that allow feeling relatively more grounded than others? (The Canadian Shield is roughly 4 billion years old and the land beneath my feet in Costa Rica is roughly 3 million years old.)
- What theories in your life have shifted with new evidence?