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Making Continents Move: The Ocean Cartography of Marie Tharp (Women in Science 31)

If you’re a scientist, and you’ve lived long enough, there’s a good chance that you’ll see your life’s work overwritten and forgotten in a long, piecemeal process blandly punctuated by retrospective award banquets every half decade or so. Science moves on, but usually at a pace that lets you keep your sense of self-worth well into your autumn years. Every so often, however, the scientific community deals the full measure of its cruelty in one concentrated blow, ripping apart a life’s work without pity or restraint while the now obsolete scientist can do little but stand mutely by and watch.

Marie Tharp (1920-2006) was one such who, after a quarter of a century of foundational geological work, had to sit still while a roomful of men dismembered her legacy and divvied up the remnants among themselves in a frenzy of violent opportunism. If there’s comfort to be had in the tale (and I’m not sure there is), it’s that Tharp’s life was so full of disappointment and maddening inertia that she might have been largely immune to misery by the time she sat ringside, 58 years of age, at the dismantling of her life’s work.

Her father had been a soil and forest expert for the government, so her childhood was a series of dislocations – seventeen separate moves spanning the breadth of the country, never in any one place long enough to form fast friends or community roots. Her mother died when she was fifteen, and between the moving and sickness, her high school years were a somewhat tattered patchwork, here vibrant with exotic scientific trips into the backwoods of America, there darkened by black rootlessness and loss. When she headed for college, it wasn’t with any particular notion of life direction. Tharp tried her hand at several subjects before she more or less stumbled into a geology program that had the promise of a job in the petroleum industry at its end. It was the late Thirties, jobs were scarce, and doubly so for women. She applied, and was accepted.

            Her coursework in the program was something of an intellectual smorgasbord, a crazy quilt of the mind that mixed geology with chemistry with drafting with mathematics, in fact anything that might conceivably be of use in an indistinct future career. As it happened, that idiosyncratic mixture of skills would be precisely the thing that kept her alive in the lean years to come. As promised, she received a job in the petroleum industry upon graduating, an uninspiring grind of a job that left no room for critical thinking or basic humanity. Taking a chance, she married a nondescript male named David Flanagan in 1948 and moved with him to New York, where the exciting work in geology was happening.

She showed up at Columbia University, asking for employment, and was given a place in the basement with the rest of “Doc” Ewing’s eccentric team of rogue geologists. Packed into their domain like cordwood, the Ewing team worked for little to no pay devising crazy shoestring instruments to measure the geological properties of the Earth. They crafted coring devices, magnetometers, and sonar equipment from old tin cans and other salvaged materials, but their favorite medium was explosives. On land, they had achieved much success in determining how earthquakes propagate by setting off massive explosions and measuring the resulting ripples, so they figured, why not try that in the ocean too?

Today, we are too aware of the delicacy of oceanic ecosystems to engage quite so liberally in Blowing Stuff Up by way of scientific investigation, but at the time Ewing’s team’s unorthodox devices opened up brand new ways of probing the unviewable depths of the ocean floor. Tharp was originally assigned as a draftsman and calculator, but when the team moved to more spacious grounds at the Lamont mansion (becoming the Lamont Team in the process), she turned into a sort of all-jobs factotum for the whole group. The work was stressful, small on gratitude, and not particularly intellectually challenging.             So, she ran away. Got in her car and headed for her father’s farm with the intention of never returning. But as the time passed, and the grimness of her future outside of the Lamont group loomed large, she allowed herself to be coaxed back by Ewing, though with the understanding that she would no longer be handling everybody’s passing whims. Instead, she would work for one man – Bruce Heezen. They began their joint career in 1952, and would end it only in 1977 with Heezen’s sudden death In between, they would remake the world.

Prior to Tharp and Heezen, there were dozens of theories about how the world worked, geologically, among which was a wildly unpopular notion called continental drift, the brainchild of Alfred Lothar Wegener. He had argued in 1915 that the complementary shapes of Africa and South America, when combined with the similarity of the rock formations and fossils found along the coasts, represented powerful proof that the continents had once been combined, and had been slowly drifting apart for ages. Mocked and reviled and eventually forgotten, especially in America, people couldn’t embrace continental drift because they couldn’t conceive of an explanatory mechanism behind it.

In 1952, Heezen gave Tharp a stack of boxes containing all of the sounding data of six ocean cartographic missions that the Lamont team had undertaken. She was to put it all together and use her knowledge of geology and mathematics to interpolate between the data points to come up with a plausible map of the ocean floor. Through painstaking analysis and an intelligent choice of scale, she noticed something that had no business being in the data – a rift that seemed to run down the middle of the Atlantic Ocean, surrounded by mountain ranges on either side. If it was true, it represented a possible mechanism for continental drift.

Heezen looked at her work, saw the association with an incredibly unpopular theory and the danger of their work being discounted utterly if it came to be associated with that theory, and demanded that Tharp start over. She did, and the results were the same, and he still wouldn’t believe what was in front of him until another of his assistants, who was plotting earthquake epicenters, laid his earthquake map over Tharp’s ocean floor map, and the epicenters lined up perfectly along the rift that wasn’t supposed to be there. The rift was real, and was the location of powerful geological events that could drive the motion of the continents.

It was a momentous discovery, but one that the Lamont group was perfectly happy sitting on for years. The first paper mentioning the find wasn’t released until four years later, but the real vindication came at an oceanography conference in 1959 when Jacques Cousteau took the stage and dramatically confessed to having been a skeptic when it came to continental drift, so much of one that he assembled a mission particularly to disprove the theory. He constructed a sled that skid along the ocean floor, taking footage as it went. That footage, in point of fact, produced the first video evidence of the rift it was meant to discredit, and launched the public rehabilitation of the continental drift model.

While Heezen was invited to speak and write about the rift and its implications for the development of the planet, Tharp remained largely in the shadows, diligently working away at her maps, finding ways to make them more accessible while still maintaining scientific rigor. While plate tectonics exploded as a theoretical discipline, the woman whose interpolations and scientific instinct had made the explosion possible was rarely acknowledged even as her maps spread throughout the geological community.

As Heezen and Tharp took on the responsibility for mapping the world’s oceans, their private relationship grew closer. Tharp had divorced her husband, and Heezen was too busy with his work to maintain any steady outside relationship. They drifted together, and formed a working unit made of equal parts love, respect, and conflict. While they never married, they were in the minds of everybody who worked with them a couple, and when Heezen died in 1977, Tharp would spend the rest of her life curating and organizing their joint legacy.

The partnership was thus a source of strength, the firm foundation from which Tharp went on to map first the Indian and South Atlantic, and eventually the world, but at the same time was a liability. Heezen had a propensity for doing things on his own terms, and for ignoring crises he’d rather not face, all of which culminated in his suspension from the Lamont group, a reversal of fortune that dragged Tharp along after him. And while his contacts with the Navy allowed the pair to continue their oceanic cartography, it deepened Tharp’s dependence on Heezen’s personal connections. Having had a solid position at Lamont, she was now tied to the unsteady ship of Heezen’s individual fortune. That would ultimately work heavily against her in the decades after Heezen’s death.

In the meantime, there was the work. Weeks bent over maps, organizing misfit high school students who camped out at her home while assisting with the data analysis that fed her topographic drafting, and days in airplanes and on ships, watching the data tick in, harnessing the power of the first on-board computers to crunch numbers and give her the shape of the ocean floor as they sailed over it. In 1977, it all came together in the WOFP, or World Ocean Floor Panorama, the first map to display all of the rifts and fissures crackling through the sea bed, giving the public a visceral sense of the dynamic geology beneath the sea, and how it pushes the formation of features on land.

The World Ocean Floor Panorama.
The World Ocean Floor Panorama.

Heezen, who had given a quarter century to collecting the data which went into producing the map, lived to see the proofs of the grand joint effort, but died before it went to print. Tharp was left to pick up the pieces as best she could, to fit grieving in somewhere between meetings with printers, color experts, and the geologists who were hungry to share between them Heezen’s legacy. In 1978, Tharp was invited to a session of the General Bathymetric Chart of the Oceans’ guiding committee, which was planning what was to be done in the future with the WOFP. Tharp expected, as the guiding mind behind oceanic cartography since 1952, to be given, if not oversight of the entire next edition, at least her choice of the world’s oceans. As it turned out, the world had already been carved up and distributed to hungry oceanographers before the meeting had even started. She watched ocean after ocean snatched from her grasp, her prospects for future work chopped to a few sectors around Australia, hardly enough to sustain her financially or intellectually for more than a few months.

And yet, she had nearly three decades left to live, to somehow fill. After having been engaged in bracing and fulfilling work with an exciting if exasperating partner, she now found herself alone, her services unwanted, with nothing to do but catalogue the past and read her discoveries reduced to a footnote in the history of oceanography. Like Elizebeth Friedman, the death of her intellectual partner shunted her from a career of creating new works for the future to a life of preserving what she had done, should that future decide at some point to care.

She died in 2006, the product of her and Bruce’s joint life tucked neatly away in the Library of Congress, quietly awaiting that grateful future.




Marie Tharp shows up as one of the cartoonified Heroes of Science in Neil deGrasse Tyson’s new COSMOS, and the representation is a good deal more accurate than the whitewashing of Giordano Bruno from earlier in the series, though I suppose that isn’t saying much. Soundings: The Story of the Remarkable Woman Who Mapped the Ocean Floor (2012) by Hali Felt is an interesting book about an area of science one doesn’t normally ponder too often. It does, however, fall into the bloggish tendency of thinking that we can’t possibly hear enough about the biographer and their writing process, with the result that the book begins and ends with a dozen pages of Felt more or less talking about herself. It’s not as egregious as in George D. Morgan’s execrable Rocket Girl, but the self indulgence gets pretty uncomfortable after a while. But her love of Tharp shines through the more tortured attempts at historical creative writing and awkward self-insertion, and that makes up for a lot.

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