Marie Tharp - Pioneer of the Deep

Marie Tharp was a pioneer who revealed the hidden landscapes of the ocean floor and transformed geology forever.

Marie Tharp was born on July 30, 1920, in Ypsilanti, Michigan. Her father, William, worked as a surveyor for the U.S. Department of Agriculture, making soil and land maps. As a young girl, Marie often helped her father with his fieldwork. She carried tools, looked at soil samples, and learned how maps were made. This early experience sparked her lifelong interest in maps and geography. Because of her father’s job, Marie moved often and attended 17 different schools before finishing high school.

After her mother died in 1936, Marie took a year off to help her father on their family farm before starting college. She began her studies at Ohio University in 1939 and graduated in 1943 with a degree in music and English, along with several minors. At first, Marie thought she would become a teacher, since few career paths were open to women. But World War II created new opportunities. With so many men serving in the military, universities began to recruit women for science programs. Marie was accepted into a special geology program at the University of Michigan, where she earned her master’s degree in 1944. A few years later, she also completed a degree in mathematics from the University of Tulsa.

In 1948, Marie moved to New York and began working at Columbia University’s Lamont Geological Laboratory. There she met Bruce Heezen, a young geologist who would become her research partner for the next 30 years. Together, they set out to map the ocean floor.

At the time, scientists knew very little about what lay beneath the ocean’s surface. Many believed the seafloor was flat and featureless. Women were not allowed on research ships, so Bruce collected sonar data at sea, while Marie stayed behind and turned the numbers into detailed maps. Using pens, rulers, and patience, she slowly pieced together the hidden shapes of the deep ocean.

Marie’s drawings revealed something no one had seen before: the ocean floor was filled with mountains, valleys, and ridges. In the early 1950s, while mapping the North Atlantic, she noticed a huge crack running down the middle of a long underwater mountain range. This was the Mid-Atlantic Ridge, and the crack looked like a rift valley where the seafloor was splitting apart. Marie realized this was evidence of seafloor spreading, a process where the ocean floor slowly moves apart as new crust forms.

At first, her colleagues dismissed her findings because she was a woman and because the idea of “continental drift” was still controversial. Many scientists believed the continents had always been fixed in place. But Marie’s maps provided the missing evidence to prove the theory correct. Eventually, Bruce and others accepted her conclusions. Together, Marie and Bruce expanded their maps to include the South Atlantic, Indian, Arctic, Antarctic, and Pacific Oceans. Their work culminated in 1977 with the first complete map of the world’s oceans, published just weeks after Bruce’s sudden death.

Marie retired in 1983 but continued to run a small map distribution business and write about her research. For many years, her contributions were overlooked, but later in life she began receiving recognition. In 1996, she received the Outstanding Achievement Award from the Society of Women Geographers, and in 1997, the Library of Congress named her one of the century’s greatest cartographers. She passed away in 2006 at the age of 86.

Today, Marie Tharp is remembered as a pioneer in science and one of the most important mapmakers in history. She revealed the deep structures of the ocean and provided the key evidence for plate tectonics, one of the most important scientific theories of the 20th century. Her determination and vision helped uncover a hidden world and forever changed our understanding of the Earth.

References:
“The Ages of Exploration.” Ages of Exploration, exploration.marinersmuseum.org/subject/marie-tharp/.
“Marie Tharp.” AAG, 12 Jan. 2022, www.aag.org/memorial/marie-tharp/.

Key words:
Science, Innovation, Courage, Perseverance, Achievement, Responsibility, Challenge Injustices, Make a Difference

Image Citation:
Public Domain

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