Alfred Wegener Timeline

In 1906, Wegener participated in the first of his four Greenland expeditions, later regarding this experience as a decisive turning point in his life. He returned in 1908.

Wegener joined the new Danish Expedition to Queen Louise Land, which involved only four men, took place in 1912–1913, and had Koch as leader. Wegener's main interest was meteorology, and he wanted to join this Denmark-Greenland expedition scheduled for mid-1912.

In summer 1913 the expedition team crossed the Greenland inland ice, the four participants covering a distance twice as long as Fridtjof Nansen's southern Greenland crossing of 1888.

In April–October 1929, Wegener embarked on his third expedition to Greenland, which laid the groundwork for the German Greenland Expedition which he planned to lead in 1930–1931.

Wegener's last Greenland expedition was in 1930, leading the German Greenland Expedition. He felt personally responsible for its success, as the German government had contributed $120,000 ($1.5 million in 2007 dollars). Wegener died in Greenland in November 1930; his story is told in "Greenland Journey," based on members' accounts and the leader's diary.

Six months after Wegener's death, on 12 May 1931, Wegener's skis were discovered on the Greenland ice sheet, marking a somber milestone in the search for traces of the lost expedition leader.

From at least 1910, Wegener imagined the continents once fitting together not at the current shoreline, but 200 m below it, at the level of the continental shelves, where they match well.

Wegener only published his idea after reading a paper in 1911 which criticised the prevalent hypothesis that a bridge of land once connected Europe and America, on the grounds that this contradicts isostasy.

Later in 1912, Wegener made a case for his theory in a long, three-part article published in July 1912, along with a shorter summary, publicly advocating that all continents were once joined in a single landmass.

On 6 January 1912, Wegener presented his first proposal of continental drift in a lecture to the Geologische Vereinigung at the Senckenberg Museum in Frankfurt am Main, suggesting that the continents are slowly drifting around the Earth (Kontinentalverschiebung).

Despite the war, Wegener was able in 1915 to complete the first version of his major work, Die Entstehung der Kontinente und Ozeane ("The Origin of Continents and Oceans"), laying out his continental drift theory in detail.

In 1922 the third, fully revised edition of "The Origin of Continents and Oceans" appeared, and discussion began on his theory of continental drift, first in the German-language area and later internationally. Émile Argand advocated Wegener's theory at the 1922 International Geological Congress, and an American edition followed in 1925.

In November 1926, Wegener presented his continental drift theory at a symposium of the American Association of Petroleum Geologists in New York City, organised at the initiative of Willem van der Gracht, again earning rejection from everyone but the chairman.

The last German edition of "The Origin of Continents and Oceans", published in 1929, revealed the significant observation that shallower oceans were geologically younger.

Image source: Continental drift

In 1943, George Gaylord Simpson wrote a strong critique of the theory (as well as the rival theory of sunken land bridges) and gave evidence for permanentism — the idea that similarities of flora and fauna between continents were best explained by fixed land masses periodically connected and disconnected by flooding.

By early 1953, samples taken from India showed that the country had previously been in the Southern hemisphere, exactly as predicted by Wegener's continental drift hypothesis.

By 1959 the theory had enough supporting data that minds were starting to change, particularly in the United Kingdom where, in 1964, the Royal Society held a symposium on the subject. Wegener's book was not translated into English until 1962, and an English language edition appeared in 1966, with a British edition by Methuen, London in 1968.

The Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, was established in 1980 on Wegener's centenary, honouring his contributions to polar research.

Image source: Alfred Wegener Institute for Polar and Marine Research

Wegener was posthumously recognised as the founding father of one of the major scientific revolutions of the 20th century, as plate tectonics vindicated his once-rejected continental drift hypothesis.

With the advent of the Global Positioning System (GPS) in 1993, it became possible to measure continental drift directly, providing conclusive confirmation of the movement Wegener proposed over eight decades earlier.