Marie Tharp (1920-2006): Pioneer Geologist and Bathymetrist

  • March 8th marked International Women’s Day.  At TCarta, this day inspired discussion of influential female mathematicians, scientists and engineers in the world of technology in general and the world of marine mapping more specifically.  Marie Tharp, pioneer bathymetrist, rose to the top of the discussion.

    Smithsonian Magazine. “Seeing is Believing: How Marie Tharp Changed Geology Forever”. Photo Credit: Lamont-Doherty Earth Observatory and the estate of Marie Tharp

    As Smithsonian Magazine’s Erin Blakemore reports in Seeing Is Believing: How Marie Tharp Changed Geology Forever during World War II, like many other female contemporaries, Marie Tharp seized professional opportunities she would not have had if so many men were not away at war.  With masters degrees in mathematics and geology, Tharp pursued a profession of interest in traditionally male-dominated scientific fields. Finally, Tharp was brought in to draft maps of the ocean floor for Columbia University’s Lamont Geological Laboratory (known today as Lamont-Doherty Earth Observatory):

    “It was thankless work in a time before computers; Tharp had to comb through an  enormous pile of sonar soundings and plot out her measurements by hand. Still, she found inspiration in the very mystery of the task. ‘The whole world was spread out before me,’ she recalled in a 1999 essay about the Lamont-Doherty Earth Observatory. ‘I had a blank canvas to fill with extraordinary possibilities...It was a once-in-a-lifetime— a once-in-the-history-of-the-world —opportunity for anyone, but especially for a woman in the 1940s.’”  

    Tharp’s drafting work resulted in the discovery of the 10,000-mile-long Mid-Atlantic Ridge which also lent visible credibility to the controversial (at the time) theory of plate tectonics. According to Tharp, her discovery of the Ridge—a finding that showed that the seafloor was spreading—was initially dismissed as “girl talk” by Bruce Heezen, the scientist who had collected many of the sounding points Tharp had assimilated in her drafting.  It took more than a year for Heezen to see value in the finding, influenced also by signs of earthquakes occurring along the rift. Tanzeen ultimately published Tharp’s results and took credit for it—announcing his findings in 1956.

    The map created by Tharp and Heezen. Smithsonian Magazine. Image Credit: Lamont-Doherty Earth Observatory and the estate of Marie Tharp.

    Tharp and Hezeen’s findings were “no less than a seismic event in geology” as they made visible a major geologic feature of the earth that was disbelieved up until then (Blakemore).  Tharp believed that the visual presentation of the findings in an accessible format was a key factor to the impact on public understanding.  In her 1999 essay, Connect the Dots: Mapping the Seafloor and Discovering the Mid-ocean Ridge, Tharp describes the importance of her choice of mapping style, “the physiographic diagrams gave us a way to publish our data. In retrospect, our choice of map style turned out to be significant because it allowed a much wider audience to visualize the seafloor.”

    In her book on Tharp, Hali Felt theorizes that Tharp must have been “an extremely humble and modest person who seemed to genuinely not need external validation for her work.”   In her own writing, Tharp confirms this eloquently while celebrating the importance of her life’s work:

    "I worked in the background for most of my career as a scientist, but I have absolutely no resentments. I thought I was lucky to have a job that was so interesting. 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. You could only do that once. You can’t find anything bigger than that, at least on this planet."

    Find Marie Tharp interesting like TCarta does? Read more on Marie Tharp in the above-mentioned Smithsonian article by Erin Blakemore and Tharp’s 1999 essay, or check out Hali Felt’s book Soundings: The Story of the Remarkable Woman Who Mapped the Ocean Floor.