Alfred Wegener

Early life and education Alfred Wegener was born in Berlin on 1 November 1880, the youngest of five children, to Richard Wegener and his wife Anna. His father was a theologian and teacher of classical languages at the Joachimsthalschen Gymnasium and Berlinisches Gymnasium zum Grauen Kloster. In 1886 his family purchased a former manor house near Rheinsberg, which they used as a vacation home. Wegener attended school at the Köllnische Gymnasium on Wallstrasse in Berlin, completing his Abitur in 1899, Despite becoming a doctor in the field of astronomy, Wegener had always maintained a strong interest in the developing fields of meteorology and climatology, and his studies afterwards focused on these disciplines. In 1905 Wegener became an assistant at the near Beeskow. He worked there with his brother Kurt, who was likewise a scientist with an interest in meteorology and polar research. The two pioneered the use of weather balloons to track air masses. On a balloon ascent undertaken to carry out meteorological investigations and to test a celestial navigation method using a particular type of quadrant ("Libellenquadrant"), the Wegener brothers set a new record for a continuous balloon flight, remaining aloft 52.5 hours from 5–7 April 1906. His observations during his time at the Observatorium made a significant contribution to the field of atmospheric physics. and a shorter summary. Second Greenland expedition Plans for a new Greenland expedition grew out of Wegener and Johan Peter Koch's frustration with the disorganisation and meager scientific results of the Danmark expedition. The new Danish Expedition to Queen Louise Land would involve only four men, take place in 1912–1913, and have Koch for leader. Inside their hut they drilled to a depth of 25 m with an auger. In summer 1913 the team crossed the inland ice, the four expedition participants covering a distance twice as long as Fridtjof Nansen's southern Greenland crossing in 1888. Only a few kilometres from the western Greenland settlement of Kangersuatsiaq the small team ran out of food while struggling to find their way through difficult glacial break-up terrain. But at the last moment, after the last pony and dog had been eaten, they were picked up at a fjord by the clergyman of Upernavik, who just happened to be visiting a remote congregation at the time. Family Later in 1913, after his return Wegener married Else Köppen, the daughter of his former teacher and mentor, the meteorologist Wladimir Köppen. The young pair lived in Marburg, where Wegener resumed his university lectureship. There his two older daughters were born, Hilde (1914–1936) and Sophie ("Käte", 1918–2012). Their third daughter Hanna Charlotte ("Lotte", 1920–1989) was born in Hamburg. Lotte would in 1938 marry the famous Austrian mountaineer and adventurer Heinrich Harrer, while in 1939, Käte married Siegfried Uiberreither, Austrian Nazi Gauleiter of Styria. World War I As an infantry reserve officer Wegener was immediately called up when the First World War began in 1914. On the war front in Belgium he experienced fierce fighting but his term lasted only a few months: after being wounded twice he was declared unfit for active service and assigned to the army weather service. This activity required him to travel constantly between various weather stations in Germany, on the Balkans, on the Western Front and in the Baltic region. Nevertheless, he 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"). His brother Kurt remarked that Alfred Wegener's motivation was to "reestablish the connection between geophysics on the one hand and geography and geology on the other, which had become completely ruptured because of the specialized development of these branches of science." Interest in this small publication was however low, also because of wartime chaos. By the end of the war Wegener had published almost 20 additional meteorological and geophysical papers in which he repeatedly embarked for new scientific frontiers. In 1917 he undertook a scientific investigation of the Treysa meteorite. Postwar period In 1919, Wegener replaced Köppen as head of the Meteorological Department at the German Maritime Observatory (Deutsche Seewarte) and moved to Hamburg with his wife and their two daughters. publishing Die Klimate der geologischen Vorzeit ("The Climates of the Geological Past") together with his father-in-law, Wladimir Köppen, in 1924. 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. Withering criticism was the response of most experts. In 1924 Wegener was appointed to a professorship in meteorology and geophysics in Graz, a position that was both secure and free of administrative duties. Scientific assessment of his second Greenland expedition (ice measurements, atmospheric optics, etc.) continued to the end of the 1920s. In November 1926 Wegener presented his continental drift theory at a symposium of the American Association of Petroleum Geologists in New York City, again earning rejection from everyone but the chairman. Three years later the fourth and final expanded edition of "The Origin of Continents and Oceans" appeared. Third Greenland expedition In April–October 1929, Wegener embarked on his third expedition to Greenland, which laid the groundwork for the German Greenland Expedition which he was planning to lead in 1930–1931. Fourth Greenland expedition: Death Wegener's last Greenland expedition was in 1930. The 14 participants under his leadership were to establish three permanent stations from which the thickness of the Greenland ice sheet could be measured and year-round Arctic weather observations made. They would travel on the ice cap using two innovative, propeller-driven snowmobiles, in addition to ponies and dog sleds. Wegener felt personally responsible for the expedition's success, as the German government had contributed $120,000 ($1.5 million in 2007 dollars). Success depended on enough provisions being transferred from West camp to ' ("mid-ice", also known as Central Station) for two men to winter there, and this was a factor in the decision that led to his death. Owing to a late thaw, the expedition was six weeks behind schedule and, as summer ended, the men at ' sent a message that they had insufficient fuel and so would return on 20 October. On 24 September, although the route markers were by now largely buried under snow, Wegener set out with thirteen Greenlanders and his meteorologist Fritz Loewe to supply the camp by dog sled. During the journey, the temperature reached and Loewe's toes became so frostbitten they had to be amputated with a penknife without anaesthetic. Twelve of the Greenlanders returned to West camp. On 19 October the remaining three members of the expedition reached ''''. Expedition member Johannes Georgi estimated that there were only enough supplies for three at '''', so Wegener and 27-year-old native Greenlander Rasmus Villumsen took two dog sleds and made for West camp. (Georgi later found that he had underestimated the supplies, and that Wegener and Villumsen could have overwintered at Eismitte. ==Continental drift theory==

and the continents drifting apart. Its spatial and temporal classification corresponds to his conception at that time, not to the later proven positions and geological epochs. Wegener first thought of this idea by noticing that the different large landmasses of the Earth almost fit together like a jigsaw puzzle. The continental shelf of the Americas fits closely to Africa and Europe. Antarctica, Australia, India and Madagascar fit next to the tip of Southern Africa. But 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. Wegener's main interest was meteorology, and he wanted to join the Denmark-Greenland expedition scheduled for mid-1912. He presented his continental drift hypothesis on 6 January 1912. He analysed both sides of the Atlantic Ocean for rock type, geological structures and fossils. He noticed that there was a significant similarity between matching sides of the continents, especially in fossil plants. ) From 1912, Wegener publicly advocated the existence of "continental drift", arguing that all the continents were once joined in a single landmass and had since drifted apart. He supposed that the mechanisms causing the drift might be the centrifugal force of the Earth's rotation ("") or the astronomical precession. Wegener also speculated about sea-floor spreading and the role of the mid-ocean ridges, stating that "the Mid-Atlantic Ridge ... zone in which the floor of the Atlantic, as it keeps spreading, is continuously tearing open and making space for fresh, relatively fluid and hot sima [rising] from depth." However, he did not pursue these ideas in his later works. In 1915, in the first edition of his book, '''', written in German, Wegener drew together evidence from various fields to advance the theory that there had once been a giant continent, which he named "''''" (German for "primal continent", analogous to the Greek "Pangaea", meaning "All-Lands" or "All-Earth"). Expanded editions during the 1920s presented further evidence. (The first English edition was published in 1924 as The Origin of Continents and Oceans, a translation of the 1922 third German edition.) The last German edition, published in 1929, revealed the significant observation that shallower oceans were geologically younger. It was not translated into English until 1962. (The currently accepted rate for the separation of the Americas from Europe and Africa is about 2.5 cm/year.) While his ideas attracted a few early supporters such as Alexander Du Toit from South Africa, Arthur Holmes in England the hypothesis was initially met with scepticism from geologists, who viewed Wegener as an outsider and were resistant to change. Nevertheless, the eminent Swiss geologist Émile Argand advocated Wegener's theory in his inaugural address to the 1922 International Geological Congress. Charles Schuchert commented: Wegener was in the audience for this lecture, but made no attempt to defend his work, possibly because of an inadequate command of the English language. 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 the idea that similarities of flora and fauna between the continents could best be explained by these being fixed land masses which over time were connected and disconnected by periodic flooding, a theory known as permanentism. Alexander du Toit wrote a rejoinder to this the following year. Alfred Wegener has been mischaracterised as a lone genius whose theory of continental drift met widespread rejection until well after his death. In fact, the main tenets of the theory gained widespread acceptance by European researchers already in the 1920s, and the debates were mostly about specific details. However, the theory took longer to be accepted in North America. ==Modern developments==

of the world were mapped in the second half of the 20th century. In the early 1950s, the new science of paleomagnetism pioneered at the University of Cambridge by S. K. Runcorn and at Imperial College by P.M.S. Blackett was soon producing data in favour of Wegener's theory. By early 1953 samples taken from India showed that the country had previously been in the Southern hemisphere as predicted by Wegener. 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. The 1960s saw several relevant developments in geology, notably the discoveries of seafloor spreading and Wadati–Benioff zones, and this led to the rapid resurrection of the continental drift hypothesis in the form of its direct descendant, the theory of plate tectonics. Maps of the geomorphology of the ocean floors created by Marie Tharp in cooperation with Bruce Heezen were an important contribution to the paradigm shift that was starting. Wegener was then posthumously recognised as the founding father of one of the major scientific revolutions of the 20th century. With the advent of the Global Positioning System (GPS) in 1993, it became possible to measure continental drift directly. ==Awards and honours==

The Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, was established in 1980 on Wegener's centenary. It awards the Wegener Medal in his name. The crater Wegener on the Moon and the crater Wegener on Mars, as well as the asteroid 29227 Wegener, the Wegener Peninsula in Eastern Greenland and the peninsula where he died in Western Greenland near Ummannaq, , are named after him. The European Geosciences Union sponsors an Alfred Wegener Medal & Honorary Membership "for scientists who have achieved exceptional international standing in atmospheric, hydrological or ocean sciences, defined in their widest senses, for their merit and their scientific achievements." ==Selected works==

• •  (Presented at the annual meeting of the German Geological Society, Frankfurt am Main, 6 January 1912). • • (1922) • (1929) • English language edition:   British edition: Methuen, London (1968). • Köppen, W. & Wegener, A. (1924): Die Klimate der geologischen Vorzeit, Borntraeger Science Publishers. English language edition: The Climates of the Geological Past 2015. • ==See also==