In the work she’s most known for, Marie Tharp wielded not a trowel but a pen, but from her drafting table at the Lamont Geological Observatory in Palisades, NY, she could see the entire ocean floor.
Oceans cover most of the surface area of our planet, hiding a worldwide network of magnificent, rugged mountain chains where new crust is formed and pushed outward. Marie Tharp’s work revealed that world to us for the first time.
Having earned degrees in geology and mathematics, she moved to Columbia University’s Lamont Geological Observatory in 1948. Tharp quickly became responsible for organizing and compiling the ocean sounding data sent back by Bruce Heezen on his research voyages.
In 1952, Marie identified a key feature of the ridge dividing the North Atlantic: a V-shaped cleft running perfectly through its center. “I thought it might be a rift valley that cut into the ridge at its crest and continued all along its axis,” she said. This was a controversial assertion during the decades-long debate over continental drift.
Together, Marie and Bruce published the first physiographic map of the North Atlantic in 1957, and over the following 20 years they extended their mapping to all of the world’s oceans.
While they never argued for continental drift, their maps and their interpretation of the ridges spurred the debate and prompted others to propose new mechanisms and theories. By the time Marie retired in 1983, plate tectonics had been widely accepted; she had witnessed – and helped to foster – a complete transformation of her field.
Read more about Marie Tharp in this blogpost by David Bressan, Marie’s reflections that I quoted from, and her obituary from the Lamont-Doherty Earth Observatory (formerly the Lamont Geological Observatory).
Written by Meg Rosenburg (@trueanomalies)
Edited by Tori (@ToriHerridge)
Posted by Suzie (@suzie_birch)
Image: Marie Tharp, sitting at her desk at Columbia’s Lamont Geological Observatory, 1956. Image source: Lamont Archives, Lamont-Doherty Earth Observatory. Not to be reproduced without permission.