Groundbreaking map of the ocean floor created by technician Marie Tharp and Professor Bruce Heezen, image via The Earth Institute, Columbia University.
Together, Marie and Bruce rewrote 20th century geophysics by creating the first systematic, comprehensive map of the entire ocean floor. This paved the way for general acceptance of the theories of continental drift and plate tectonics.
The New York Times described Marie’s work as follows:
One day in 1952, Heezen gave Tharp a stack of soundings (sonar measurements of the ocean depth) for the Atlantic Ocean with the injunction, “Here, do something with these.” These measurements were anything but systematic; they merely reflected the paths of research ships plying the Atlantic. Tharp and an assistant set out to plot the depth measurements on huge sheets of paper. At first Tharp would create the two-dimensional profile of the sea floor for each ship track. As they gathered more data, she then began to imagine those numbers and profiles into a three-dimensional, underwater landscape with mountains and valleys and sloping plains on the sea floor, normally invisible under miles of water. It was not just science but also a supreme act of rigorous creativity, because she had to intuit the lay of the land in many places where measurements were still missing.
Marie’s drafts confirmed the existence of the Mid-Atlantic Ridge, a mountain range on the ocean floor. But they also showed a valley down the center of the ridge, a seam between continental plates. The idea of continental drift was unpopular at the time and it took Marie a year to convince Bruce of the validity of her drawings. Finally convinced, Bruce nearly lost his faculty position at Columbia when the Earth Institute heard of the findings. With support from the US Navy and National Geographic, Marie and Bruce relocated their work to Marie’s East Nyack, NY home. The map above was published in 1977 with the help of Austrian painter Heinrich Berann.
A new biography of Marie Tharp was just published and can be found on Amazon.