Alfred Wegener's theory of continental drift and scientific legacy

Alfred Lothar Wegener (1880-1930), German meteorologist, Arctic explorer and a brilliant interdisciplinary scientist, is best known as for his theory of "continental displacement" (that became famous, later, as the theory of continental drift). Since the technological means for proving the theory had not yet been developed and the idea was a radical departure from the scientific thinking of the time, Wegener's theory was widely rejected during his lifetime. After gradual accumulation of evidence in support of the idea, the theory finally gained acceptance in the early sixties. This paper gives a brief biography of Alfred Wegener, his theory of continental drift and other contributions to the world of science.

Early Life & Education

Alfred Wegener was born on November 1, 1880 in Berlin. His father was a minister and ran an orphanage. Even as a young boy Wegener was interested in walking, skating and hiking that he put to use in several Arctic expeditions later in his life. Wegener studied in Berlin, Heidelberg and Innsbruck and earned his PhD in astronomy from the University of Berlin in 1904. However, he was more interested in geophysics and started to study the emerging sciences of meteorology and climatology. He spent most of his life studying these fields rather than astronomy. ("Alfred Wegener 1880-1930," 1998- A Science Odyssey Web site; Waggoner, 1996.) In 1906 he made his first expedition to Greenland to study polar air circulation. On his return, he joined the University of Marburg as a lecturer, but again took time off in 1912-13 on another expedition to Greenland. Before going on his second Greenland expedition, Wegener got married to the daughter of one of the leading meteorologists in Germany. He also joined the Army and fought in World War I before being discharged in 1914 after being wounded.

Initial Idea of the Theory of Continental Drift

While at Marburg, in 1911, Wegener noticed the matching coastlines of South America and Africa on either side of the Atlantic and also came across a scientific paper that listed fossils of identical plants and animals found on opposite sides of the Atlantic. He was intrigued by the phenomenon and began to investigate further the similarity of organisms separated by vast oceans. The existing scientific theory at the time explained such similarity by the conjecture that "land bridges" (now sunken) had once connected far-flung continents. (Waggoner, 1996.)

Wegener was not convinced by the theory of "land bridges" and combined the 'remarkable fit' (like a jig-saw puzzle) of the African and South American coastlines with the geological and paleontological evidence to develop his theory of Continental drift. He first put forward the idea in 1912 that the continents had at one time been joined together in one land mass before drifting apart.

Evidence for the Theory

Wegener was not the first person to suggest the possibility and knew that in order for such a revolutionary theory a lot of back-up evidence was required. He, therefore, set about the task of finding the evidence with typical tenacity. He noticed that large-scale geological features on separated continents often matched very closely when the continents were brought together. For example, the Appalachian mountains of eastern North America matched with the Scottish Highlands, and the distinctive rock strata of the Karroo system of South Africa were identical to those of the Santa Catarina system in Brazil. Further evidence for his theory was found in fossils. It was discovered that fossils found in many places indicated a climate utterly different from the present-day climate. This was evident in, for example, the discovery of fossils of tropical plants on the Arctic island of Spitsbergen. (Waggoner, 1996) All of these facts supported Wegener's theory of "continental drift." The theory was put together by Wegener in his book The Origin of Continents and Oceans which he published in 1915. Expanded editions of the book were published in 1920, 1922, and 1929.

Panagea

In his "Origin of Continents and Oceans" Wegener explained that all the continents had been joined in a single mass or super-continent about 300 million years ago (he called the mass "Pangaea" -- Greek for "all the Earth"). He proposed that the Western Hemisphere continents moved eastward and butted against the western shores of Europe and Africa and the Southern Hemisphere continents had nestled together on the southern flank of the "Pangaea." Wegener suggested that under the action of forces associated with the rotation of the earth, the continents had broken apart, opening up the Atlantic and Indian oceans. (Wilson, 1963)

Support for his Theory

There were some notable exceptions among the scientists who supported Wegener's theory during his lifetime, the South African geologist Alexander Du Toit being one of them. He supported the theory as an explanation for the close similarity of strata and fossils between Africa and South America. A Swiss geologist, Emile Argand, also considered the theory of continental collisions as the best explanation for the folded and buckled strata that he had observed in the Swiss Alps.

Corroboration

Increased exploration of the Earth's crust, notably the ocean floor, began in the 1950s and by the late 1960s, the theory of " plate tectonics" was supported and accepted by almost all geologists. Although the 'plate tectonics' differs in part from Wegener's theory about the movement of continents "plowing through the ocean floor" it did prove conclusively that the continents (and the oceanic crust) are not static and both move. Scientists have also mapped and explored the great system of oceanic ridges that are the sites of frequent earthquakes, where molten rock rises from below the crust and hardens into new crust. It is now even possible to measure the speed of continental plates' movement with a high degree of accuracy by using satellite technology. All of this validates Wegener's basic theory of continental drift.

Other Contributions

As we noted in the introduction, Wegener was a versatile inter-disciplinary scientist and he made other significant contributions to Science besides his theory of 'Continental Drift.' He led several expeditions to Greenland where he conducted research to measure the thickness of ice and the rate of drift. He made a significant observation in the 4th edition of his book, "The Origins of the Continents" that shallower oceans were geologically younger. Wegener also made several key contributions to meteorology by pioneering the use of balloons to track air circulation, and writing a textbook on thermodynamics of air that became standard throughout Germany. ("Alfred Wegener 1880-1930," 1998- from A Science Odyssey Website)

Last Expedition

Wegener along with 14 others set out on a meteorological expedition to Greenland to study the jet stream in the upper atmosphere in September 1930. Due to the extreme cold many of his companions turned back but Wegener pushed on in temperatures as low as 54° C. To reach the winter station after a 15 day journey. While returning to base camp, the next morning, he got caught in a blizzard and died. His body was not found until the next summer: he was almost exactly 50 years old when died. (Watson, 1999)

Conclusion

Alfred Wegener was without doubt a brilliant scientist and a visionary who could see beyond the stereotypical scientific thoughts of his time. The vindication of his theory of the Continental Drift and the development of the theory of plate tectonics (which is largely based on Wegener's idea) after his death are ample proofs of and a tribute to his remarkable vision.