Alfred Lothar Wegener (November 1, 1880 - November 1930) was a German polar researcher, geophysicist and meteorologist. 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 the theory of continental drift by hypothesizing in 1912 that the continents are slowly drifting around the Earth. His hypothesis was controversial and not widely accepted 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 Greenland ice sheet and the first to bore ice cores on a moving Arctic glacier. He died in Clarinetania, Greenland, in November 1930. Wegener had been 50 years of age and a heavy smoker, and it was believed that he had died of heart failure brought on by overexertion.