The devastating earthquake in Nepal marked the centenary of Alfred Wegener’s theory of continental drift or plate tectonics, which explains seismic activity in the Himalayas. India impinges upon Asia at the rate of 2 cm per year, buckling the seabed of the ancient Tethys Ocean which stood between and throwing up the Himalayas. In the century since the publication of Wegener’s Die Entstehung der Kontinente und Ozeane (The Origin of Continents and Oceans) in 1915, India has ploughed 2 metres deeper into Asia. The velocity may be infinitesimal but it’s a whole subcontinent on the move, generating titanic forces. The US Geological Service estimates that it will cost Nepal $10 billion to rebuild, and the damage done to millions of lives is irreversible.
In his rather short lifetime (1880-1930), Wegener was appreciated for his work at the confluence of meteorology, climatology and polar research, the sexy science of the period. On the first of four expeditions to Greenland, he built the island’s first weather station near Danmarkshavn. Decades before jet streams were formally recognised, he may have observed the activity of the polar stream, which modern jetliners like to ride in higher latitudes. And polar weather stations remain crucial for tracking climate change.
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But science remembers Wegener for an intuitive insight — he noted that the continents fit with each other like the pieces of a jigsaw puzzle. India from the Malabar coast up to Gujarat could comfortably nestle up against the western shores of Africa, with the island of Madagascar sandwiched in between. And the western seaboard of Africa, from the Cape to the Bight of Benin, is like a mirror image of the eastern coast of South America. The match suggests that aeons ago, the continents were joined at the hip.
Wegener published the basis of his theory in 1912, in a paper in Geologische Rundschau, the official journal of the Geological Union. Two years later, he was drafted for the Great War and wounded. While convalescing, he wrote the landmark work on continental drift, The Origin of Continents and Oceans. Little more than a monograph at 94 pages, it appeared exactly a century ago. Perhaps the title owed something to Charles Darwin’s The Origins of Species, which helped to validate Wegener’s theory — fossils of the same species are found on the shores of continents which would fit nicely together, but for the thousands of miles of ocean in between.
In his 1915 work, Wegener proposed the existence of a gigantic Urkontinent (Hellenised in the literature as Pangaea), a supercontinent whose plates disarticulated and drifted apart in the world ocean to produce the present continents. And then they barged into each other, creating volcanic and seismic activity — and mountains like the Himalayas. And grief, besides.
Initially, continental drift was severely contested. In 1922, Wegener wrote: “For a proper judgement upon [the issue], an enormous mass of facts must be collected together from such sciences as geophysics, geology, palaeontology, palaeoclimatology, animal and plant geography, and geodesy.” Tectonic plates were mapped after his lifetime, establishing the validity of his theory.
Wegener explained “displacement theory” (plate tectonics) for the lay reader in the May 1922 issue of the UK magazine Discovery: “Antarctica, Australia, and India were formerly in immediate contact with South Africa, India then being the southern end of a long projection from the Asiatic Continent, which is now almost entirely crumpled up and forms the Himalayas.” The “crumpling” continues, accumulating stresses for centuries until they are released in quakes. The BBC reports that a fortnight ago, fieldwork by CEA, the French agency for alternative and atomic energy, had found a buildup on one faultline from1344. It was released in Saturday’s earthquake.