University of Arizona

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Marie Tharp

How Her Maps of the Ocean Floor Revolutionized the Earth Sciences

This exhibit highlights the work of Marie Tharp (1920-1986), geologist and oceanographic cartographer. She created the first comprehensive map of the ocean floor and is credited with discovering the Mid-Atlantic Ridge. The discovery of the Mid-Atlantic Ridge and other ridges and rifts in the ocean helped to prove continental drift, which at the time was considered “scientific heresy” and thought to be impossible. The maps paved the way for the theories of continental drift, seafloor spreading and plate tectonics to become well-established in the scientific world. She weathered criticism from her colleagues and overcame the obstacles of working as a woman scientist during the 1950’s. At first when Heezen and Doc Ewing wrote articles about the rift, Tharp was not included in the list of authors, although others said that they couldn’t have written those articles or made presentations about it without her work.

She received multiple awards during her lifetime, including the Hubbard Award by the National Geographic Society and the Mary Sears Woman Pioneer in Oceanography Award by Woods Hole Oceanographic Institute.