Marie Tharp Historical Map Brought the Seafloor to The World

Marie Tharp's groundbreaking Marie Tharp map presents the seabed to the world. Her profound knowledge of geology has taken her to unique levels.

If you walk to the hall of an academy of earth sciences you will see on one of the walls there is a nice map of the seabed for the exhibition. This Marie Tharp map was completed in 1977. This map is a reflection of Marie Tharp's excellent and acclaimed career and Marie Tharp's biography. She has worked as a cartographer and geologist at Columbia University. In the first three decades of her career, she shocked the world by creating a Marie Tharp historical map of what the seabed looked like.

Many American scientists in the twentieth century revolted against the division of continents. According to them, the continents were not divided properly. But Marie Tharp's groundbreaking map changed that view and paved the way for scientists to study plate tectonics.

Tharp was the right person at the right place at the right time to map out the details of the seabed. In the right way, she was the right woman. Being a woman had some limitations professionally. But she was able to take advantage of the open doors of history. She has been able to make significant contributions in both science and cartography. The maps might never have come without her.

Looking at this Marie Tharp map of hers, remember that in the 1940s, for any person, especially for a woman, such an opportunity came once in a lifetime and even once in the history of the whole world. It's really a big deal to combine the nature of time, the state of science, and all the logical, irrational, big, and small events.

Tharp's cartographic roots

Tharp's cartographic roots were very deep. She was born in 1920 in Michigan. As a young woman, she helped out with household chores. She used to go on field trips to survey with her father and make maps for the United States Bureau of Agriculture. Marie Tharp recalls, “After finishing high school, I went to about two dozen schools and saw different landscapes. I think mapping is in my blood, but I didn't want to follow in my father's footsteps. "

According to Marie Tharp's biography, Tharp was a student at Ohio University in 1941. After the attack on Pearl Harbor, young men on campus joined the military in groups. The campus is empty. Due to this sudden shortage of male students, the Department of Geology at the University of Michigan is open to women. Marie Tharp took advantage of this opportunity and took a few classes. "We had 10-12 girls from all over America with us," Marie Tharp said in an oral interview in 1994.

Tharp graduated in 1943 with a summer field course in geological mapping and began working as a part-time draftsman for the US Geological Survey. She took a job at an oil company in Oklahoma but was frustrated by the lack of fieldwork or research. So she enrolled in a night class at the University of Tulsa to pursue a second master's degree in mathematics.

She moved to New York City

In 1948 she moved to New York City. She went to Columbia University's Department of Geology for a job and had the opportunity to be interviewed for her advanced degree. But the only vacant position for women was the draftsperson, who would help male graduate students work in geology. Marie Marie Tharp has done this before. She got a job researching fossils at the American Museum of Natural History, but she chose the job of a draftsman in Columbia University's Department of Geology because it seemed more promising to her.

The following year, Marie Tharp was assigned to the newly established Lamont Geological Observatory in Colombia. She was one of the first women to find herself here. Soon she will have the opportunity to work with Bruce Heezen, a geologist who has just completed his Ph.D. Like other male scientists at Lamont, Heezen was initially busy collecting ocean data. Marie Tharp used to analyze the data plots and maps he collected. She was more qualified to do this.

Naomi Oreskes, a science historian at Harvard University, says in her book Science on a Mission: How Military Funding Shaped What We Do and Don't Know About the Ocean: staying at home to analyze [the data], ”.

Basically, women were not allowed to go on research ships

Banned from sea expeditions, Marie Tharp used all her energies to map the seabed, beginning with the North Atlantic. This Marie Tharp historical map contributes to two important discoveries. To create the map she first translates the collected echo sound of the ship crossing the sea then slices the 2-dimensional verticals of the terrain below the ship's track. This seabed profile shows a wide ridge running through the middle of the Atlantic. Although this map was created in the 19th century, Marie Tharp noticed a notch near the top of the ridge in each profile. Her idea was that the notches represented a single uninterrupted running deep valley in the center of the Mediterranean. If her idea is correct, the valley could be a single crack through which molten material rises from the bottom, forming a new crust and separating the seafloor. This information is evidence for continental flow.

This idea gained popularity in Europe. But Heezen, like most scientists at the time, was in favor of considering it a scientific heresy. Marie Tharp later wrote in Natural History. This crack is real, it took Heezen about a year or more to understand it. It took a few more years to complete the first map of the North Atlantic, and in 1957 it was completed.

Tharp and Heezen had to travel around the U.S. Navy's Cold War area to publish First Map and share their work with other scientists. They use contour lines to indicate depth for detailed topographic maps. This was one of the reasons the pair adopted a new cartographic style called physiographic diagrams. It is a three-dimensional sketch of the terrain as seen through the window of an aircraft. To do this, Marie Tharp had to use her geological training and knowledge, and experience of land mapping. Knowledge and skills like her have never been seen among any other typical research assistant and draftsperson.

Physiographic Maps

Earlier, physiographic maps were used to show the continental segments with standard symbols. Each type of hill, valley, plain, and desert was shaped in a certain way. Marie Tharp and Heezen first used this technique to show what an unknown unseen terrain might look like. Marie Tharp draws a strip of seabed along each profile to illustrate what kind of landform each bump and dip can be. She then identifies a single pattern to fill in the blanks in the profile.

"The amount of work involved in taking it from just from those soundings and being able to create that is just amazing," said historian Judith Tyner, author of Women in American Cartography.

While Marie Tharp was making his map, an unsaturated project was taking shape on the drafting table next to him. Heezen hired a recent art school graduate to plot thousands of earthquake-centric plots in the Atlantic Ocean to help find a safer place to set up a transoceanic cable. The sub-centers he plotted lined up along the Rift Valley in Marie Tharp. This relationship reinforces the idea that the crack was pulling the crust towards itself there. This allows Marie Tharp to find a way to find the cracks in the ship's track.

This 1958 North Atlantic Sea diagram by Heezen and Marie Tharp is the most complete map of the seabed ever prepared.

Ronald Doyle, a science historian at Florida State University in Tallahassee, said: "The marvelous thing about that map is how comprehensive it looked on rather limited data."

At first, the American Scientific community was skeptical of the speculative nature of this map. It is wide and about 60,000 kilometers long.

Physiographic Methods

The innovative use of physiographic methods by Marie Tharp and Heezen has helped scientists understand that the East African Rift divided the continent, with the submarine Rift Valley suggesting that the continents on both sides of the Atlantic moved away from each other.

In 1983  Heezen and  Marie Tharp receive a grant from the US Navy to work with Berran to work on a complete map of the world's seabed. It took the trio four years to create their iconic cartographic masterpiece.

Heezen died of a heart attack at the age of 53. Work on the map was completed a few weeks before he died. After his death, Marie Tharp could not continue her work due to a lack of funds and data sources, which meant the end of her career. It may take decades for her contribution to be fully recognized. She died of cancer in 2006. Before she died, she received honorary awards from several organizations. Lamont-Doherty Earth Observatory and Library of Congress declared her one of the four best cartographers of the twentieth century.

Although her name was pronounced after Heezen and her contribution to her work was not mentioned in many newspapers, she never regretted it. In 1999, she said, "I thought I'd be lucky to have a job that was so interesting." Rift Valley and the Mediterranean ridge are spread over about 40,000 miles around the world, you will not find anything bigger on this planet.