Marie Tharp's discovery of the Mid-Atlantic Ridge showed that the sea floor was spreading, validating the theory of plate tectonics. She was born #OTD in 1920, and was an American geologist and oceanographic cartographer — and she co-created first comprehensive map of the ocean floor. 🌍🗺 . . . . . . . . . . #womeninscience #science #earth #nature #sea #history #sciencehistory #life #world #women #womancrush #ocean #map #cartography #mapmaking #techtonics #seafloor #underwater #knowledge #inspiration #motivationmonday