In 1912 Alfred Wegener proposed a controversial theory about how the Earth’s land masses formed. He said the great continents had once formed a single landmass, which had broken up over time. The idea went against all conventional ideas, and was roundly dismissed.
It took the work of young cartographer Marie Tharp to prove him right.
In 1947, she worked on a team that were running expeditions around the world, mapping the ocean floors with echolocation. However, Marie wasn’t allowed on the missions because women were seen as ‘bad luck’…
But the work she did back at the university was invaluable. Converting endless data into detailed profiles, she realised that the ocean floor isn’t a flat, featureless plane, but a complex, varied landscape.
Most importantly, she spotted a long, V-shaped valley in each of her profiles: a rift valley that supported Wegener’s theory, formed by two land masses moving apart, splitting the ocean floor in two.
But even with this evidence, Tharp’s ideas were dismissed as ‘girl talk’.
She then realised that her profiles tied in with worldwide earthquake maps being developed by a colleague.
The mounting evidence started to convince some sceptics, but not all. Renowned explorer Jacques Cousteau was so unconvinced that he sent an expedition to film the ocean floor and clear things up once and for all. What did his footage show? Exactly what Tharp had predicted.
Tharp’s steadfast determination had paved the way for Wegener’s continental drift theory to gain traction. As the tide of opposition waned, it gave birth to our modern understanding of plate tectonics and secured Tharp’s position as one of the most outstanding cartographers of the 20th century.