The Man Who Made the Earth Move

Claire Eamer

Just about this time of year, back in 1930, one of the most famous figures in modern geology lay down to die on the snow-covered ice cap of Greenland. On November 1, Alfred Wegener celebrated his 50th birthday with friends at a tiny, temporary meteorological station on the glacier. The next day, he and one companion - a young Greenlander named Rasmus Villumsen - hitched up the sled dogs and headed back to the coast to rejoin their main party.

They never made it. In the spring, his friends found Wegener's body, laid out carefully on a reindeer hide and buried in snow. Villumsen was never found.

Wegener explaining continental drift - as depicted by
illustrator Sa Boothroyd.
From Before the World Was Ready: Stories of Daring Genius in Science

Unsung Hero

Today, Wegener is a celebrated hero in the world of geology, but that wasn't true when he died. Then he was a meteorologist and polar scientist with a weird idea that drove many geologists into a frenzy. The continents, Wegener said, weren't stuck in place. Instead, they moved - ever so slowly - around the globe, breaking apart to create oceans and coming together to create mountain ranges. He called his theory Continental Drift.

Most geologists hated the idea. They couldn't see how continents could move (and Wegener couldn't explain that either), and they were deeply offended that a mere meteorologist would stick his nose into their science. By the time of his death, Wegener had been amassing evidence and arguing his theory for 20 years without convincing them.

It would be another 30 years after Wegener's death before the geological world took him seriously. What it took was the discovery of a mechanism that explained the movement of the continents.

Marie and the Ocean Floor

Mapping the sea floor with sound waves.
Illustration by Sa Boothroyd, from
Before the World Was Ready (Annick Press 2013)

One of the first to recognize the mechanism was an American geologist, Marie Tharp. In 1952, an American survey ship was trundling up and down the Atlantic Ocean, using new technology involving sound waves to study the ocean floor. Back in the lab, Tharp was drawing ocean-bottom maps based on the ship's data.

She spotted a formation more familiar from land - a rift valley, created when two bits of earth's crust pull apart. And it meant, she realized, that the ocean bottom was spreading, getting wider. That meant that the continents on either side were moving apart, just as Wegener had said.

It took months before Tharp could convince her colleagues that the ocean really was growing wider. Even then, most geologists still considered Wegener sadly mistaken - at best.

The Canadian Connection

One of the scientists who took the evidence of ocean spreading a bit more seriously was Canadian geologist and physicist John Tuzo Wilson. He later said it took him almost a decade to accept the idea that the continents move, but once he did, there was no stopping him.

Tuzo Wilson realized that Earth's surface is made up of massive plates that move around, pushed and pulled by the forces in the planet's molten core. He pioneered the study of what is now called plate tectonics in a now-classic 1965 journal article called  "A New Class of Faults and their Bearing on Continental Drift." It was the vindication and elaboration of Wegener's much-despised theory from 35 years earlier.

And if Wegener hadn't died on that remote icefield in 1930, he might still have been around - a hale and hearty 85-year-old - to enjoy the triumph.

Want to Know More?

The story of Alfred Wegener and Marie Tharp and a few others is in my new book, Before the World Was Ready: Stories of Daring Genius in Science (Annick Press 2013).

There's plenty of information about Wegener on the Internet. Here's a good site, with links about different aspects of plate tectonics. And here's a lovely bio of Marie Tharp, in her own words.

John Tuzo Wilson was a science communicator as well as a scientist. He spent more than a decade as director general of the Ontario Science Centre in Toronto. Here's a short biography of J. Tuzo Wilson (as he was usually called), and here's a longer one.

Clues in the Rocks

By Claire Eamer

“The role of a geologist is much like the role of a crime scene investigator,” says Joel Cubley, geology instructor at Yukon College in Whitehorse. Geologists try to figure out what happened long ago in Earth’s history from small, fragmentary clues, he explains. But what took place long ago was certainly not small.

Cubley’s specialty is tectonics, and that’s just about as big as it gets. It’s the study of the movements of the great plates that carry the continents slowly over the face of Earth, pushing up mountains and excavating oceans as they go.

Out there, beyond the east coast of Newfoundland,
the Atlantic Ocean is slowly getting wider.
Claire Eamer photo

Tectonics is a relatively new field. About a century ago, German scientist Alfred Wegener suggested that the continents move, but most geologists thought he was talking nonsense. It wasn’t until well into the 1950s that American scientists using sound waves to map the ocean floors found proof of Wegener’s theory. Marie Tharp, one of the few women working in geology at the time, spotted what looked like a rift valley on the floor of the North Atlantic Ocean. It turned out to be exactly that — a place where two parts of Earth’s crust are pulling apart, widening the ocean and pushing Europe and North America away from each other about as quickly as your fingernail grows.

Even that slow movement, over time, can create huge changes. On the west side of North America, tectonic movement has thrown up range after range of mountains between the eastern slopes of the Rockies and the Pacific Coast. Cubley is particularly interested in gap between a couple of those ranges, a place where two sections of crust have moved in a way that stretches the surface rock. It’s a 200-kilometre-wide zone of jumbled ridges and valleys called the Grand Forks Complex, lying roughly between Castlegar and Revelstoke in southern British Columbia and extending down into Washington State.

The snow-capped St. Elias Mountains, the highest
in Canada, were created by slow tectonic movement.
Claire Eamer photo

A feature of the Grand Forks Complex is occasional outcrops of metamorphic rocks, hundreds of millions of years older than the surrounding rock. How did they get there? That, in simple terms, was the subject of Cubley’s doctoral research.

“Metamorphic rocks are just rocks that have been cooked,” he says. Where Earth’s crust is pulling apart strongly enough to create a crack or fault, super-hot “cooked” rock can well up from far below the surface. Cubley suspected that the metamorphic rock in the Grand Forks Complex was evidence of a fault. But where?

In places like the Great Rift Valley in Africa, the fault is obvious – and huge. But the fault associated with the metamorphic rocks of the Grand Forks Complex would be much smaller and harder to spot. Cubley tackled the problem in the traditional geologist’s way, by sampling and mapping rocks on foot.

He spent several summers bushwhacking across the rough, wild landscape of south-central British Columbia, camping, hauling gear, and swatting bugs. When he finally found the fault, it was a bit of a let-down.

“It was a shallow ravine full of scrubby trees,” says Cubley. “That was kind of soul-destroying!”

But not for long. Cubley’s soul bounced back, and he’s well on his way to understanding how that modest ravine is linked to the unusual rocks of the Grand Forks Complex.

What he knows at this point is that the metamorphic rocks were formed at a depth of about 20 kilometres and a temperature of about 750 degrees C. Roughly 50 million years ago (almost yesterday in geologic terms), they welled all the way up to the surface and then cooled very quickly.

“I still can’t explain how they got to the surface that quickly,” Cubley says. But, with the help of a great deal of modern technology (and some more bushwhacking), he’s working on it.