Wilson, J. Tuzo (1908-1993)
Canadian geophysicist
An early proponent of the continental drift theory, J. Tuzo Wilson is chiefly remembered for his proposition that transform faults were present in the ocean floor, an idea that led to conclusive evidence that the sea floor and the earth's crust are constantly moving. Wilson later hypothesized that an ancestral Atlantic Ocean basin had opened and closed during the Paleozoic Era, in turn creating the huge land mass known as Pangaea. This theory helps account for the presence of the Appalachian mountains in eastern North America, the striking similarity of many rock features in Western Europe and North America, and parallel cyclical developments on the seven continents.
John Tuzo Wilson was born in Ottawa, Ontario, Canada. His father, John Armitstead Wilson, was an engineer who held a civil service position. His mother, Henrietta Tuzo, was an avid mountain climber who met her husband at the first gathering of Canada's Alpine Club. The Wilsons later shared their love of geology and the outdoors with their children, who were brought up to respect the pursuit of knowledge and were educated under the direction of an English governess.
In 1924, Wilson's father obtained a position for him at a forestry camp. Wilson grew so fond of outdoor work that he signed on as an assistant to the legendary mountaineer Noel Odel, who persuaded him to pursue a career in geology. Following his freshman year at the University of Toronto, Wilson switched majors from physics to geology. After earning a B.A. in 1930, Wilson received a scholarship to study at Cambridge University under Sir Harold Jeffreys. When Wilson returned to Canada in the early 1930s, he had difficulty finding work, so he continued his education, enrolling in Princeton University, where he earned a Ph.D. in 1936. He made the first recorded ascent of Mount Hague in Montana in 1935, and in 1938 married Isabel Jean Dickson, with whom he eventually had two children.
With the outbreak of World War II in 1939, Wilson joined the Canadian Army. During his seven-year stint, he authored more than 500 technical reports and later claimed that these military papers had helped him develop the lucid prose style that he utilized in a number of scientific studies. By 1946, he had reached the rank of colonel. That same year, after resigning from the army, he succeeded his professor at the University of Toronto. Geophysics had finally become a lucrative field of study in Canada, thanks in large part to the discovery of oil in Alberta, which increased demand for geophysical exploration and led to the development of more advanced instruments and measurement techniques. Wilson investigated a number of geological mysteries, including Canadian glaciers, mountain building, and mineral production. He conducted these investigations with a characteristic reverence toward nature: "Everywhere in science modern tools and ideas bring to light the elegant and orderly skeins by which nature builds the glory that we see about us, knit in regular patterns from simple stitches," he wrote in I.G.Y.: The Year of the New Moons (1961). "Indeed, we may think of all nature in terms of music, as infinitely ingenious and elaborate variations on a few simple themes."
From 1957 to 1960, Wilson served as president of the International Union of Geodesy and Geophysics. During his tenure he led a series of geologic expeditions to China and Mongolia, the details of which are recorded in his highly praised book, One Chinese Moon (1959). In the early 1960s, he became a key figure in what was then the most controversial issue in geology—the continental drift theory.
The origins of the continental drift theory date back hundreds of years. Since the time of the first global maps people have reasoned that at one time the continents might have been a single huge land mass. However, the first formal hypothesis of continental drift was made by German geophysicist Alfred Wegener in 1912. The idea was generally overlooked for decades but reemerged prominently in 1960, when geologist Harold Hess theorized that the ocean floors were being continuously created and changed. Hess attributed this activity to two physical structures: mid-ocean ridges, where the ocean floor is created, and ocean trenches, where the sea floor is destroyed.
Wilson was one of the first scientists to recognize the immense implications of this idea. For the next decade, he was at the very center of this theoretical debate. Using Hess's theory, Wilson postulated the existence of a third category of physical structure on the ocean floor which he called "transform faults," horizontal shears located between ridge sites and trenches. He suggested that transform faults could not exist unless the earth's crust was moving, and that the physical confirmation of these faults might prove the scientific validity of the continental drift theory. In 1967, seismologist Lynn Sykes partially tested Wilson's theory by studying seismic patterns and oceanic focal mechanisms. Wilson brought the idea to the attention of the general public by exhibiting a continental drift model at Montreal's Expo '67. By the late 1960s, the theory had gained wide acceptance and was eventually incorporated into the larger concept of plate tectonics, which maintains that the Earth's lithosphere is made up of a number of plates that move independently.
Wilson's hypothesis and the publicity it garnered earned him numerous honors, including a Fellowship in the Royal Society (1968), the Penrose Medal of the Geological Society of America (1968), the Walter H. Bucher Medal of the American Geophysical Union (1968), the John J. Carty Medal of the National Academy of Sciences (1975), the Vetlesen Prize of Columbia University (1978), and the Wollaston Medal of the Geological Society of London (1978).
Wilson retired from his professorship at the University of Toronto in 1974. He then assumed the directorship of the Ontario Science Centre and in that capacity helped transform the center from a traditional science museum into an interactive science lab for public use. Of the center's roughly 1,000 exhibits, 400 were designed to be handled by patrons, and during the late 1970s and 1980s, the exploratory museum attracted approximately 1.5 million visitors annually.
Throughout his life Wilson traveled extensively. He lectured at more than 200 colleges and universities. One of his passions was collecting books on the Arctic and Antarctic, both of which he had visited. A mountain range in Antarctica was named the Wilson range in his honor. He died in Toronto at the age of 84.
Convergent Plate Boundary; Divergent Plate Boundary; Sea-Floor Spreading
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