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Tuesday, November 1, 2022

Continents Shift theory - Alfred Wegener !

I have seen this leftarm seamer bowl well – was surprised to find that he has played 59 tests and taken 246 wickets, he is yet to play ODI or T20Is.   Neil Wagner is   South African born, but plays for New Zealand  after waiting for 4 years.    A match haul of 8 for 126 in a 40-run victory over India at Eden Park in February 2014 ensured him a regular place.  No post on Cricketer but on another namesake (thanks to Geologist Prof Mu Ramkumar)

Kumari Kandam, a mythical continent, is  believed to be lost with an ancient Tamil civilization, supposedly located south of present-day India in the Indian Ocean.  In the 19th century, some European and American scholars speculated the existence of a submerged continent called Lemuria to explain geological and other similarities between Africa, Australia, the Indian subcontinent and Madagascar. A section of Tamil revivalists adapted this theory, connecting it to the Pandyan legends of lands lost to the ocean, as described in ancient Tamil and Sanskrit literature. According to these writers, an ancient Tamil civilisation existed on Lemuria, before it was lost to the sea in a catastrophe. Remember reading a serial story in my school days  on Lemuria by Pushpa Thangathurai in Dinamani Kathir (thought there was too much of sexy descriptions) 

The hero of the post was no ordinary man – with his multidisciplinary calling, started out as an astronomer, being correct when he stated that craters on the Moon are the work of meteorites and not of volcanoes; later, he combined meteorological studies in Greenland with his geological theories, and did not have a steady job until after the age of 40, when an Austrian University created a post for him. He was a difficult scientist to pigeonhole. And for geologists he was an outsider who dared to question the foundations of their science, so most of them rejected his ideas with the backing of figures like Einstein, who wrote the prologue to a book that ridiculed him.

If there were a “geographical forecast”, analogous to the predictions of meteorologists, it would show how over the next 100 million years the Atlantic Ocean will continue to expand, until it is much larger than the Pacific. And also how Africa will merge with Europe, with the Mediterranean disappearing and a mountain range emerging in its place to compete with the Himalayas—although Everest and its neighbouring mountains will still continue to rise. If this sounds shocking today, you should put yourself in the shoes of geologists back in 1912, who were much more troubled when a 32-year-old German meteorologist, launched his theory of continental drift. Thanks to his hypothesis, any child today knows that the continents are slowly moving and were joined together at the time when the dinosaurs appeared.

Ever since the appearance of the first world maps, many people had noticed how well Brazil fits snugly under the belly of Africa. Alfred Wegener (1880 – 1930) looked for other connections. He found research on identical fossils on the coasts of Africa and South America, something for which geologists, convinced that the world map was immutable, had offered a more implausible explanation: land bridges that had vanished after permitting animals and plants to travel from one continent to another.

In addition, thanks to geolocation satellites, we are now able to detect that Europe and North America are moving apart, although at the same speed that a fingernail grows: two metres in a lifetime. Today we have all learned at school—or even before, in cartoons—the theory of continental drift. But Wegener died in 1930, long before his success was recognised.  But no matter how many bridges were dreamt up, the most renowned geologists were unable to explain why in Africa there are marking of glaciers or why near the North Pole there are remains of tropical vegetation in the form of coal. For Wegener this was only possible if the current continents were once concentrated around the equator forming a supercontinent, which broke apart some 200 million years ago and which he called Pangaea. Nobody had thought of relating all these facts, but Wegener saw in them the evidence of continental drift, thanks to his interest in different sciences.

Alfred Lothar Wegener  was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher. During his lifetime he was primarily known for his achievements in meteorology and as a pioneer of polar research, but today he is most remembered as the originator of continental drift hypothesis by suggesting in 1912 that the continents are slowly drifting around the Earth. His hypothesis was controversial and widely rejected by mainstream geology until the 1950s, when numerous discoveries such as palaeomagnetism provided strong support for continental drift, and thereby a substantial basis for today's model of plate tectonics. Wegener was involved in several expeditions to Greenland to study polar air circulation before the existence of the jet stream was accepted. Expedition participants made many meteorological observations and were the first to overwinter on the inland  

In 1905 Wegener became an assistant at the Aeronautisches Observatorium Lindenberg near Beeskow. He worked there with his brother Kurt, two years his senior, 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.  In that same year 1906, Wegener participated in the first of his four Greenland expeditions, later regarding this experience as marking a decisive turning point in his life. The Denmark expedition was led by the Dane Ludvig Mylius-Erichsen and charged with studying the last unknown portion of the northeastern coast of Greenland. During the expedition Wegener constructed the first meteorological station in Greenland near Danmarkshavn, where he launched kites and tethered balloons to make meteorological measurements in an Arctic climatic zone.  

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”).  Interest in this small publication was however low, also because of wartime chaos

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).  

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 −60 °C (−76 °F) 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.  Expedition member Johannes Georgi estimated that there were only enough supplies for three at Eismitte, so Wegener and Rasmus Villumsen took two dog sleds and made for West camp.   They took no food for the dogs and killed them one by one to feed the rest until they could run only one sled. While Villumsen rode the sled, Wegener had to use skis, but they never reached the camp: Wegener died and Villumsen was never seen again. After Wegener was declared missing in May 1931, and his body found shortly thereafter, Kurt Wegener took over the expedition's leadership in July, according to the prearranged plan for such an eventuality.

This expedition inspired the Greenland expedition episode of Adam Melfort in John Buchan's 1933 novel A Prince of the Captivity.  Wegener died in Greenland in November 1930 while returning from an expedition to bring food to a group of researchers camped in the middle of an icecap.  He supplied the camp successfully, but there was not enough food at the camp for him to stay there. He and a colleague, Rasmus Villumsen, took dog sleds to travel to another campone which they never reached.   

Original world maps created by Alfred Wegener showing Pangaea 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. Alfred 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.  In 1915, in the first edition of his book, Die Entstehung der Kontinente und Ozeane, 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 "Urkontinent" (German for "primal continent", analogous to the Greek "Pangaea”.   

Interesting !

With  regards – S. Sampathkumar
1st Nov. 2022.


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