U.S. Navy Renames Ship to Honor Marie Tharp, a Columbia University Oceanographer

The U.S. Navy has announced it is renaming one of its oceanographic survey ships after Marie Tharp, a Columbia University geologist, oceanographer, and cartographer who drew the first modern maps of the ocean floors. The vessel previously honored Matthew Fontaine Maury, a key figure in 19th-century oceanography who quit the U.S. Navy to join the Confederacy.

The USNS Marie Tharp is a 350-foot oceanographic survey ship. The ship is currently assigned to Military Sealift Command and is in the Persian Gulf.

Marie Tharp, born in 1920, was one of the very few women trained in earth sciences up to the mid-20th century, holding degrees in geology and mathematics from Ohio University and the University of Michigan. She went to work in 1948 at what soon became Columbia University’s Lamont Geological Observatory (now Lamont-Doherty Earth Observatory). At the time, the ocean floor was thought to be largely flat and featureless. Collaborating with oceanographer Bruce Heezen, Tharp used sonar data systematically collected by research vessels to painstakingly hand-draw the first detailed maps of the Atlantic Ocean floor. She also used the survey data to help find downed military aircraft.

The Heezen-Tharp mapping project revealed in striking detail many topographic features including what is now known as the Mid-Atlantic Ridge, a continuous mountain chain spanning the ocean roughly north-south. Tharp hypothesized that a V-shaped rift running down its middle meant the ocean Toor was slowly splitting along this seam. This supported the then still controversial theory of continental drift, that the earth’s surface is in constant motion. The Atlantic map was published in 1957. Tharp soon mapped similar structures in the Red Sea, Indian Ocean, and other areas.

These maps gradually piled up with other evidence, including patterns of seafloor earthquakes and magnetism, and by the early 1970s, the continental drift idea — by then known in modified form as plate tectonics — was universally accepted. In 1977, Tharp and Heezen published the first global map of all the ocean floors.

Secretary of the Navy Carlos Del Toro noted that “Tharp’s dedication to research brought life to the unknown ocean world and proved important information about the earth, all while being a woman in a male-dominated industry.”