How One Woman's Discovery Shook the Foundations of Geology

WORLD OCEAN FLOOR PANORAMA, BRUCE C. HEEZEN AND MARIE THARP, 1977. COPYRIGHT BY MARIE THARP 1977/2003. REPRODUCED BY PERMISSION OF MARIE THARP MAPS, LLC 8 EDWARD STREET, SPARKILL, NEW YORK 10976
WORLD OCEAN FLOOR PANORAMA, BRUCE C. HEEZEN AND MARIE THARP, 1977. COPYRIGHT BY MARIE THARP 1977/2003. REPRODUCED BY PERMISSION OF MARIE THARP MAPS, LLC 8 EDWARD STREET, SPARKILL, NEW YORK 10976

By Brooke Jarvis

Marie Tharp spent the fall of 1952 hunched over a drafting table, surrounded by charts, graphs, and jars of India ink. Nearby, spread across several additional tables, lay her project—the largest and most detailed map ever produced of a part of the world no one had ever seen.

For centuries, scientists had believed that the ocean floor was basically flat and featureless—it was too far beyond reach to know otherwise. But the advent of sonar had changed everything. For the first time, ships could “sound out” the precise depths of the ocean below them. For five years, Tharp’s colleagues at Columbia University had been crisscrossing the Atlantic, recording its depths. Women weren’t allowed on these research trips—the lab director considered them bad luck at sea—so Tharp wasn’t on board. Instead, she stayed in the lab, meticulously checking and plotting the ships’ raw findings, a mass of data so large it was printed on a 5,000-foot scroll. As she charted the measurements by hand on sheets of white linen, the floor of the ocean slowly took shape before her.

Tharp spent weeks creating a series of six parallel profiles of the Atlantic floor stretching from east to west. Her drawings showed—for the first time—exactly where the continental shelf began to rise out of the abyssal plain and where a large mountain range jutted from the ocean floor. That range had been a shock when it was discovered in the 1870s by an expedition testing routes for transatlantic telegraph cables, and it had remained the subject of speculation since; Tharp’s charting revealed its length and detail.

Her maps also showed something else—something no one expected. Repeating in each was “a deep notch near the crest of the ridge,” a V-shaped gap that seemed to run the entire length of the mountain range. Tharp stared at it. It had to be a mistake.

She crunched and re-crunched the numbers for weeks on end, double- and triple-checking her data. As she did, she became more convinced that the impossible was true: She was looking at evidence of a rift valley, a place where magma emerged from inside the earth, forming new crust and thrusting the land apart. If her calculations were right, the geosciences would never be the same.

A few decades before, a German geologist named Alfred Wegener had put forward the radical theory that the continents of the earth had once been connected and had drifted apart. In 1926, at a gathering of the American Association of Petroleum Geologists, the scientists in attendance rejected Wegener’s theory and mocked its maker. No force on Earth was thought powerful enough to move continents. “The dream of a great poet,” opined the director of the Geological Survey of France: “One tries to embrace it, and finds that he has in his arms a little vapor or smoke.” Later, the president of the American Philosophical Society deemed it “utter, damned rot!”

In the 1950s, as Tharp looked down at that tell-tale valley, Wegener’s theory was still considered verboten in the scientific community—even discussing it was tantamount to heresy. Almost all of Tharp’s colleagues, and practically every other scientist in the country, dismissed it; you could get fired for believing in it, she later recalled. But Tharp trusted what she’d seen. Though her job at Columbia was simply to plot and chart measurements, she had more training in geology than most plotters—more, in fact, than some of the men she reported to. Tharp had grown up among rocks. Her father worked for the Bureau of Chemistry and Soils, and as a child, she would accompany him as he collected samples. But she never expected to be a mapmaker or even a scientist. At the time, the fields didn’t welcome women, so her first majors were music and English. After Pearl Harbor, however, universities opened up their departments. At the University of Ohio, she discovered geology and found a mentor who encouraged her to take drafting. Because Tharp was a woman, he told her, fieldwork was out of the question, but drafting experience could help her get a job in an office like the one at Columbia. After graduating from Ohio, she enrolled in a program at the University of Michigan, where, with men off fighting in the war, accelerated geology degrees were offered to women. There, Tharp became particularly fascinated with geomorphology, devouring textbooks on how landscapes form. A rock formation’s structure, composition, and location could tell you all sorts of things if you knew how to look at it.

Studying the crack in the ocean floor, Tharp could see it was too large, too contiguous, to be anything but a rift valley, a place where two masses of land had separated. When she compared it to a rift valley in Africa, she grew more certain. But when she showed Bruce Heezen, her research supervisor (four years her junior), “he groaned and said, ‘It cannot be. It looks too much like continental drift,’” Tharp wrote later. “Bruce initially dismissed my interpretation of the profiles as ‘girl talk.’” With the lab’s reputation on the line, Heezen ordered her to redo the map. Tharp went back to the data and started plotting again from scratch.

Heezen and Tharp were often at odds and prone to heated arguments, but they worked well together nonetheless. He was the avid collector of information; she was the processor comfortable with exploring deep unknowns. As the years went by, they spent more and more time together both in and out of the office. Though their platonic-or-not relationship confused everyone around them, it seemed to work.

In late 1952, as Tharp was replotting the ocean floor, Heezen took on another deep-sea project searching for safe places to plant transatlantic cables. He was creating his own map, which plotted earthquake epicenters in the ocean floor. As his calculations accumulated, he noticed something strange: Most quakes occurred in a nearly continuous line that sliced down the center of the Atlantic. Meanwhile, Tharp had finished her second map—a physiographic diagram giving the ocean floor a 3-D appearance—and sure enough, it showed the rift again. When Heezen and Tharp laid their two maps on top of each other on a light table, both were stunned by how neatly the maps fit. The earthquake line threaded right through Tharp’s valley.

They moved on from the Atlantic and began analyzing data from other oceans and other expeditions, but the pattern kept repeating. They found additional mountain ranges, all seemingly connected and all split by rift valleys; within all of them, they found patterns of earthquakes. “There was but one conclusion,” Tharp wrote. “The mountain range with its central valley was more or less a continuous feature across the face of the earth.” The matter of whether their findings offered evidence of continental drift kept the pair sparring, but there was no denying they had made a monumental discovery: the mid-ocean ridge, a 40,000-mile underwater mountain range that wraps around the globe like the seams on a baseball. It’s the largest single geographical feature on the planet.

LAMONT-DOHERTY EARTH OBSERVATORY

In 1957, Heezen took some of the findings public. After he presented on the Mid-Atlantic Ridge at Princeton, one eminent geologist responded, "Young man, you have shaken the foundations of geology!” He meant it as a compliment, but not everyone was so impressed. Tharp later remembered that the reaction “ranged from amazement to skepticism to scorn.” Ocean explorer Jacques Cousteau was one of the doubters. He’d tacked Tharp’s map to a wall in his ship’s mess hall. When he began filming the Atlantic Ocean’s floor for the first time, he was determined to prove Tharp’s theory wrong. But what he ultimately saw in the footage shocked him. As his ship approached the crest of the Mid-Atlantic Ridge, he came upon a deep valley splitting it in half, right where Tharp’s map said it would be. Cousteau and his crew were so astonished that they turned around, went back, and filmed again. When Cousteau screened the video at the International Oceanographic Congress in 1959, the audience gasped and shouted for an encore. The terrain Tharp had mapped was undeniably real.

1959 was the same year that Heezen, still skeptical, presented a paper hoping to explain the rift. The Expanding Earth theory he’d signed on to posited that continents were moving as the planet that contained them grew. (He was wrong.) Other hypotheses soon joined the chorus of explanations about how the rift had occurred. It was the start of an upheaval in the geologic sciences. Soon “it became clear that existing explanations for the formation of the earth’s surface no longer held,” writes Hali Felt in Soundings: The Story of the Remarkable Woman Who Mapped the Ocean Floor.

Tharp stayed out of these debates and simply kept working. She disliked the spotlight and consented to present a paper only once, on the condition that a male colleague do all the talking. “There’s truth to the old cliché that a picture is worth a thousand words and that seeing is believing,” she wrote. “I was so busy making maps I let them argue. I figured I’d show them a picture of where the rift valley was and where it pulled apart.”

By 1961, the idea that she’d put forward nearly a decade before—that the rift in the Mid-Atlantic Ridge had been caused by land masses pulling apart—had finally reached widespread acceptance. The National Geographic Society commissioned Tharp and Heezen to make maps of the ocean floor and its features, helping laypeople visualize the vast plates that allowed the earth’s crust to move. Throughout the 1960s, a slew of discoveries helped ideas such as seafloor spreading and plate tectonics gain acceptance, bringing with them a cascade of new theories about the way the planet and life on it had evolved. Tharp compared the collective eye-opening to the Copernican revolution. “Scientists and the general public,” she wrote, “got their first relatively realistic image of a vast part of the planet that they could never see.”

Tharp herself had never seen it either. Some 15 years after she started mapping the seafloor, Tharp finally joined a research cruise, sailing over the features she’d helped discover. Women were generally still not welcome, so Heezen helped arrange her spot. The two kept working closely together, sometimes fighting fiercely, until his death in 1977. Outside the lab, they maintained separate houses but dined and drank like a married couple. Their work had linked them for life.

In 1997, Tharp, who had long worked patiently in Heezen’s shadow, received double honors from the Library of Congress, which named her one of the four greatest cartographers of the 20th century and included her work in an exhibit in the 100th-anniversary celebration of its Geography and Map Division. There, one of her maps of the ocean floor hung in the company of the original rough draft of the Declaration of Independence and pages from Lewis and Clark’s journals. When she saw it, she started to cry. But Tharp had known all along that the map she created was remarkable, even when she was the only one who believed. “Establishing the rift valley and the mid-ocean ridge that went all the way around the world for 40,000 miles—that was something important,” she wrote. “You could only do that once. You can’t find anything bigger than that, at least on this planet.”

10 Citizen Science Projects That Need Your Help

A citizen scientist takes a photo of scarlet mushrooms.
A citizen scientist takes a photo of scarlet mushrooms.
lovelypeace/iStock via Getty Images

Channel your inner Nikola Tesla or Marie Curie by participating in actual scientific research, either out and about or without even leaving your couch. These projects unleash the power of the public to be places that researchers can’t be and to spread the workload when data start piling up. They really can’t do it without you.

1. Catalog photos of Earth's cities at night.

Photo from space of a city at night
Identify cities from the photos taken from the International Space Station.
Chris Hadfield, NASA // Public Domain

Cities at Night—a study by Complutense University of Madrid—asks people to catalog images of the Earth at night taken from the International Space Station, part of the millions of images in the Gateway to Astronaut Photography of Earth database. The current project, Lost at Night, needs people to identify cities within images of 310-mile circles on Earth. Hundreds of volunteers have classified thousands of images already, but classification by multiple individuals ensures greater accuracy. In fact, the project will determine the optimum number of people needed. The primary goal is an open atlas of publicly available nighttime images. Just log on to the image database to help.

2. Follow fish using high-tech tags.

You’ll have to go fishing—an outdoor activity you can do by yourself!—for this assignment. Volunteer to tag fish for the American Littoral Society, whose citizen scientists have tagged more than 640,000 fish since the program began in 1965. You can tag the fish you catch and release, or report tagged fish to the organization. The data is sent to the National Marine Fisheries Service Laboratory in Woods Hole, Massachusetts, where it helps scientists track the populations and movements of coastal species like striped bass, flounder, and bluefish. To get started, become a member of the American Littoral Society, which comes with a packet of tagging gear and instructions.

3. Spy on penguins in Antarctica.

Penguins on an ice floe
Keeping tabs on penguins is one way a citizen scientist can lend a hand.
axily/iStock via Getty Images

Here's another project for those stuck indoors. Penguins are threatened by climate change, fisheries, and direct human disturbance, yet scientists have little data on the birds. To fill in the gaps, 50 cameras throughout the Southern Ocean and Antarctic Peninsula take images of colonies of gentoo, chinstrap, Adélie, and king penguins year-round. You can help the University of Oxford-based research team by sorting through thousands of images to identify and mark individual adult penguins, chicks, and eggs. You'll be pinpointing seasonal and geographic variations in populations that may represent changes to the Antarctic ecosystem. Marking other animals in the images helps researchers figure out which ones are hanging around penguin colonies. Discuss a specific image or the project with the science team and other volunteers in an online forum.

4. Battle an invasive marine species.

Like to dive or snorkel? Make it count by reporting lionfish sightings or captures to the Reef Environmental Education Foundation's Volunteer Reef Survey Project. Lionfish, which are native to the Indo-Pacific, were first sighted in the South Atlantic in 1985 and were likely released by private aquarium owners. Since then, they have spread throughout the Caribbean and Gulf of Mexico and caused native fish populations to decline by up to 80 percent. Scientists say this invasion may be one of the century’s greatest threats to warm temperate and tropical Atlantic reefs. You can also join a lionfish derby to catch and kill some of the tasty fish so scientists can analyze their biology.

5. Count birds from your backyard.

Bluebirds at a bird feeder
Bluebirds dine on mealworms at a bird feeder.
MelodyanneM/iStock via Getty Images

North American birds are in trouble. Recent studies predict dramatic declines in the populations of migratory birds due to climate change—and much of the data that went into these studies came from citizen scientists who monitored species without leaving home. The Cornell Lab of Ornithology and Birds Canada launches Project FeederWatch in the winter months; you simply put out a bird feeder and report the number and species of birds that visit it. Citizen scientists can also join the Cornell Lab's NestWatch—you find a nest, monitor it every three or four days, and report your data. And every February, the Audubon Society runs the Great Backyard Bird Count, in which participants submit data to produce a real-time snapshot of bird populations across North America. Any time of the year, birdwatchers can submit lists of the birds they see on eBird, a huge database of sightings that informs public policy, conservation efforts, and other initiatives.

6. Photograph plants for climate change research.

The Appalachian Mountain Club's Mountain Watch program asks hikers to document alpine and forest plants for ecological research. By taking photos of flowers and fruiting plants along woodland trails and uploading them to the iNaturalist app, participants provide data about the times and places that plants bloom. Scientists then compile the information in an online database and analyze it for trends that could indicate changing climates.

7. Comb through ships' logbooks for weather data.

Old handwritten letters
Practice your handwriting-deciphering skills on the Old Weather project.
scisettialfio/iStock via Getty Images

Ships’ logs from mid-19th century American sailing vessels contain detailed weather observations. Citizen scientists can help transcribe observations from whaling vessels for the Old Weather project; scientists will use the information to learn more about past environmental conditions and create better climate models for future projections. Historians will also use the data to track past ship movements and tell the stories of the people on board.

8. Make American history documents and science notes accessible to more people.

The Smithsonian Libraries are stuffed with original history and science documents that have lain in drawers for decades. Help open up "America's attic" to the public by organizing and transcribing digital versions of handwritten field notebooks, diaries, logbooks, specimen labels, photo albums, and other materials. You'll join thousands of other volunteers to investigate documents like the Sally K. Ride Papers, the collection of the Freedmen's Bureau (which helped former slaves following the Civil War), and field studies of insects by the Irish naturalist Arthur Stelfox.

9. Investigate historical crimes in Australia.

Drawing of a convict ship to Australia
A drawing of a 19th-century convict ship destined for Australia.
Photos.com/iStock via Getty Images

If you're obsessed with true crime, you'll love this project. Volunteer to investigate and transcribe criminal records from 19th- and 20th-century Australia, which was founded as a British penal colony. Alana Piper, a postdoctoral research fellow at the Australian Centre for Public History at the University of Technology Sydney, will use the transcriptions to construct the "life histories and offending patterns of Australian criminals" from the 1850s to the 1940s. More than 40,000 subjects have been completed so far.

10. Map the unique features of Mars's South Pole.

Travel to Mars—without the hassle of zero gravity or space-vegetable farming—through Planet Four, a citizen science project that is currently tasked with identifying features on Mars's dynamic South Pole. Volunteers examine photos from the HiRISE camera on NASA's Mars Reconaissance Orbiter and pick out "fans" or "blotches" in the landscape of seasonal carbon dioxide ice. Scientists believe these structures indicate wind speed and direction on the Martian surface and offers clues about the evolution of the Red Planet's climate.

Why Cats Like to Shove Their Butts in Your Face, According to an Animal Behavior Expert

This cat might be happier showing off its butt.
This cat might be happier showing off its butt.
Okssi68/iStock via Getty Images

Cats are full of eccentric behaviors. They hate getting wet. Their tongues sometimes get stuck midway out of their mouths, known as a “blep.” And they’re really happy hanging out in bodegas.

Some of these traits can be explained while others are more mysterious. Case in point: when they stick their rear end in your face for no apparent reason.

Are cats doing this just to humiliate their hapless caregivers? What would possess a cat to greet a person with its butt? Why subject the person who gives you food and shelter to such degradation?

To find out, Inverse spoke with Mikel Delgado, a postdoctoral fellow at the School of Veterinary Medicine at UC Davis. According to Delgado, cats don’t necessarily perceive their rectal flaunting as anything aggressive or domineering. In fact, it might be a cat’s way of saying hello.

“For cats, it’s normal for them to sniff each other’s butts as a way to say hello or confirm another cat’s identity,” Delgado said. “It’s hard for us to relate to, but for them, smell is much more important to cats and how they recognize each other than vision is. So cats may be ‘inviting’ us to check them out, or just giving us a friendly hello.”

For a cat, presenting or inspecting a butt is a kind of fingerprint scan. It’s a biological measure of security.

Other experts agree with this assessment, explaining that cats use their rear end to express friendliness or affection. Raising their tail so you can take a whiff is a sign of trust. If they keep their tail down, it’s possible they might be feeling a little shy.

If you think this situation is eased by the fact you rarely hear cats fart, we have bad news. They do. Because they don’t often gulp air while eating, they just don’t have enough air in their digestive tract to make an audible noise. Rest assured that, statistically speaking, there will be times a cat giving you a friendly greeting is also stealthily farting in your face.

[h/t Inverse]

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