In 1912, the German meteorologist Alfred Wegener proposed that the continents of the Earth had once been joined and were slowly drifting apart — a theory geologists ridiculed for the next 50 years, until three decades after his death, when new evidence from the ocean floor proved him right

On the evening of Saturday, 6 January 1912, in the meeting hall of the Frankfurt Geological Association, a 31-year-old German meteorologist named Alfred Wegener delivered a lecture titled Die Herausbildung der Grossformen der Erdrinde (“The Formation of the Major Features of the Earth’s Crust”). Wegener was, by the standards of Germany’s pre-war geological establishment, an outsider to the discipline whose foundational assumptions he was about to challenge — an astronomer by doctoral training and an Arctic explorer by preferred fieldwork. His lecture proposed that the seven continental landmasses of the modern Earth had once been joined together in a single supercontinent, which he called Pangaea, from the Greek roots meaning “all lands,” and had since drifted apart to reach their present positions. The minutes of the meeting recorded that there was “no discussion due to the advanced hour.” The following fifty years of German, British, and American geological literature would more than compensate for the first-night silence. 

The single most-substantial paradigm shift in the recorded history of 20th-century Earth science was proposed by a meteorologist whose geological credentials the substantial majority of contemporary geologists considered essentially unqualified for the specific claim he was making. What Wegener had noticed — as had multiple previous observers, including the Flemish cartographer Abraham Ortelius in 1596 and the French geographer Élisée Reclus in 1872, neither of whom had systematically developed the observation — was the specific geometric fact that the eastern coastline of South America and the western coastline of Africa fit together with substantially unlikely precision, as though the two continental landmasses had once been physically joined and had subsequently separated. What Wegener additionally proposed, beyond the specific coastline observation his predecessors had made, was that a substantial accumulated body of geological, paleontological, and paleoclimatic evidence — that geologists working across the intervening three centuries had documented but had not systematically integrated — pointed to the same conclusion. As detailed in NASA Science’s institutional biography of Alfred Wegener and the specific evidentiary framework he assembled, the specific supporting evidence Wegener catalogued across his 1912 lecture, his April 1912 Petermanns Geographische Mitteilungen article, and his substantially expanded 1915 book Die Entstehung der Kontinente und Ozeane (“The Origin of Continents and Oceans”) included: identical fossilised species (the freshwater reptile Mesosaurus, the Triassic land reptile Cynognathus, the fern Glossopteris) found on continents currently separated by thousands of kilometres of ocean that neither species could plausibly have traversed; identical geological rock strata found on the eastern seaboard of North America (the Appalachian mountain chain) and the western coast of Scotland; substantial glacial deposits found in currently-tropical regions of India, Africa, Australia, and South America that indicated those regions had once been located in polar latitudes; and coal deposits found in Antarctica that indicated the continent had once been located in tropical latitudes.

The specific reception the geological establishment gave to Wegener’s assembled evidence was, by essentially every account of the subsequent historiographical review of the 1912-1962 period, substantially hostile. Per the American Physical Society’s summary of Wegener’s specific 1912 proposal and its subsequent rejection by the mainstream geological community, the core substantive objection that professional geologists raised against Wegener’s proposal was that he could not identify a plausible physical mechanism by which continents could actually move. The specific mechanism Wegener himself proposed — that the centrifugal force generated by the Earth’s rotation, combined with the tidal gravitational forces exerted by the Moon and Sun, could physically displace continental landmasses through the surrounding oceanic crust — was subsequently demonstrated (by the Cambridge geophysicist Harold Jeffreys in a series of substantially damaging technical papers across the 1920s) to be several orders of magnitude too weak to actually move any continental mass. Without a plausible mechanism, Wegener’s evidence — however substantial the fossil, geological, and paleoclimatic patterns it documented — could not, in the specific scientific epistemology of the interwar geological establishment, constitute an adequate case for continental drift. The 1926 American Association of Petroleum Geologists symposium in New York substantially rejected the theory. The Austrian paleoclimatologist Fritz Kerner von Marilaun dismissed Wegener’s proposal as “delirious ravings,” and Rollin T. Chamberlin at the University of Chicago characterised it as of “the footloose type” that “takes considerable liberty with our globe.” Wegener could not obtain a professorship at any German university across the entire 1912-1924 period specifically because of his identification with the continental drift theory.

What happened on the ice

Alfred Wegener died on the Greenland ice sheet in November 1930, at the age of 50, on his fourth polar research expedition. As detailed in Smithsonian Magazine’s retrospective on the century in which continental drift was considered pseudoscience, Wegener had led a team of German meteorologists to Greenland with the specific objective of establishing three permanent weather stations on the interior ice sheet to monitor Arctic weather patterns across a full annual cycle. In November 1930, Wegener and his Greenlandic guide Rasmus Villumsen attempted to travel from the central Eismitte research station back to the coastal base camp at Kamarujuk, approximately 400 kilometres away, in winter conditions that had already substantially deteriorated below the temperatures the expedition equipment had been designed to accommodate. Wegener died somewhere in the interior of the ice sheet, probably of a heart attack produced by the physical exertion of the winter travel. Villumsen buried him beneath a snow marker and continued toward the coast. Villumsen himself subsequently died in the ice; his body has never been recovered. A search party found Wegener’s body in May 1931, six months after his death, preserved in the ice with what the searchers reported was a substantially peaceful expression. He was reburied at the same location on the interior ice sheet, in what remains — 95 years later — one of the more geographically remote grave sites of any modern scientist of comparable historical significance.

The three decades after

The subsequent vindication of Wegener’s theory occurred approximately three decades after his death, on the basis of specific new evidence produced by ocean-floor research technologies that had not existed during Wegener’s lifetime. Per the University of California Berkeley’s Museum of Paleontology summary of the history of plate tectonics as an idea, the substantial expansion of ocean-floor mapping during and after the Second World War — driven initially by the specific naval requirement to understand submarine warfare acoustics, and subsequently by the specific Cold War research infrastructure that funded systematic ocean-basin exploration — produced, across the 1950s and early 1960s, three specific new bodies of evidence that Wegener had not had access to and that his critics could not adequately explain within the standard fixist paradigm. The American oceanographer Marie Tharp, working at Columbia University’s Lamont Geological Observatory under the direction of Bruce Heezen, produced across 1952-1957 the first systematic topographic map of the Atlantic ocean floor, revealing the substantial mid-Atlantic ridge and the specific rift valley running along its centre. The Princeton geologist Harry Hess proposed in a 1960 preprint (formally published in 1962) that new oceanic crust was continuously being generated at the mid-ocean ridges, spreading outward across geological time, and eventually subducting back into the Earth’s mantle at ocean trenches — a mechanism that Hess called “seafloor spreading” and that essentially solved the specific mechanism problem that had substantially destroyed Wegener’s 1912 proposal. In 1963, the Cambridge geophysicists Frederick Vine and Drummond Matthews, working in parallel with the Canadian geophysicist Lawrence Morley, demonstrated that the magnetic properties of the ocean-floor rocks on either side of the mid-Atlantic ridge formed symmetric stripes recording periodic reversals of Earth’s magnetic field — providing direct experimental evidence that the ocean floor was, in fact, spreading outward from the ridges at exactly the rates Hess had predicted. By 1968, the substantial majority of the professional geological community had accepted the resulting plate tectonic framework as the standard model of Earth’s crustal dynamics. Wegener had been proposing the framework since 1912. He had been dead for 38 years.