Alfred wegener1/17/2024 ![]() Moreover, when the continents are placed back in their Pangaean configuration, mountain belts in Scandinavia and the British Isles match up with the Appalachian Mountains in eastern North America He also determined that the petrologic (rock) records on both sides of the Atlantic show many distributions-such as ancient coal deposits- that would be continuous if the ocean did not intervene. ![]() He found the continental margins of the subequatorial portions of Africa and South America fit together with jigsaw- puzzle-like precision. Wegener accumulated a great deal of evidence to support his hypothesis, most notably the remarkable number of close affinities of geologic features on both sides of the Atlantic Ocean. Wegener’s Evidence for Continental Drift Theory | UPSC – IAS Wegener postulated a massive supercontinent, which he called Pangaea (Greek for “whole land”), as existing about 225 million years ago and then breaking apart into several large sections – the present-day continents-that have continued to move away from one another to this day.Wegener put together the first comprehensive theory to describe and partially explain the phenomenon, publishing his landmark book Die Entstehung der Kontinente und Ozeane (The Origin of Continents and Oceans) in 1915.(An Analysis of – Evidence and Rejection of the Theory)ĭuring the second and third decades of the twentieth century, the notion of continental drift was revived, most notably by the German meteorologist and geophysicist Alfred Wegener. Additional reporting by Alina Bradford, Live Science contributor.4 pieces of evidence for continental drift by Alfred Wegener 14, 2021, by Live Science Staff Writer Patrick Pester. Watch this short video on YouTube about plate tectonics and continental drift, from National Geographic.Learn more about Alfred Wegener from the NASA Earth Observatory.Learn more about the history of continental drift and plate tectonics from the U.S.He died in 1930 at age 50 just two days after his birthday while on a scientific expedition in Greenland, according to the University of Berkeley. Despite his incredible continental drift evidence, Wegener never lived to see his theory gain wider acceptance. In fact, plates moving together created the highest mountains in the world, the Himalayans, and the mountains are still growing due to the plates pushing together, even now, according to National Geographic. For example, the Appalachian Mountains (United States) and Caledonian Mountains (Scotland) fit together, as do the Karoo strata in South Africa and Santa Catarina rocks in Brazil. ![]() He also matched up rock formations on either side of the Atlantic Ocean like puzzle pieces. Wegener knew that fossil plants and animals such as mesosaurs, a freshwater reptile found only in South America and Africa during the Permian period, could be found on many continents. Wegener then assembled an impressive amount of continental drift evidence to show that Earth's continents were once connected in a single supercontinent. He was intrigued by the interlocking fit of Africa's and South America's shorelines. Tectonic plates of the Earth (Image credit: USGS)Ī map of the continents inspired Wegener's quest to explain Earth's geologic history. Related: Plate tectonics are 3.6 billion years old, oldest minerals on Earth reveal What evidence is there for continental drift? ![]() Magnetic minerals aligned in ancient rocks on continents also showed that the continents have shifted relative to one another. Alternating patterns of magnetic anomalies on the ocean floor indicated seafloor spreading, where new plate material is born. In the 1960s, scientists discovered plate edges through magnetic surveys of the ocean floor and through the seismic listening networks built to monitor nuclear testing, according to Encyclopedia Britannica. Plate tectonics is like a modern update to continental drift. For instance, as geophysicists began to realize that continental rocks were too light to sink down to the ocean floor, prominent paleontologists instead wrongly suggested that the similarities between fossils had been overestimated, Frankel said. Researchers argued over the land bridges right up until the plate tectonics theory was developed from the 1950s to the 1970s, Frankel said. And to account for the identical fossils discovered on continents such as South America and Africa, scientists invoked ancient land bridges, now vanished beneath the sea. They thought Earth's incredible mountains were created because our planet had been cooling and shrinking since its formation, Frankel said. When Wegener proposed continental drift, many geologists were contractionists. ![]()
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