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The Discoveries and Evidence leading up to Plate Tectonics
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Continental Drift
German scientist Alfred Wegener proposes his theory of continental drift, which is rejected at first, but is eventually modified into plate tectonics. The theory of continental drift was that the continents were once a giant super continent, called Pangea, but it eventually broke up and floated away. One of the main problems with Wegener`s hypothesis is that he could not explain what moved the continents. -
Arthur Holmes Research
In 1929, as Wegener`s continental drift idea was being rejected, one scientist named Arthur Holmes began to investigate. Arthur Holmes investigated the idea that mantle undergoes thermal convection. This idea has to do with the denisty of a subsatnce and it`s heat. Holmes found that this idea could be similar to a conveyor belt and that the mantle undergoing thermal convection could have caused the continents to move. At the time, it was not seriously considered. -
Sonar Technology Advances
Around this time period during World War 2 scientist had been trying to map the ocean since the mid 1800s but advances in technology created a sound navigation and ranging system (Sonar) which used sound waves to find different things in the ocean. At the time it was used to find enemy submarines, but it was eventually used to map the ocean. Mapping the ocean helped to research and find evidence of sea floor spreading. -
R. Deitz`s Idea
After years since Wegener`s ideas and Holmes`s ideas R. Deitz`s forms his ideas on the subject and publishs them. They were never as popular as the next idea though (Harry Hess`s). -
Plate Tectonics
John Tuzo Wilson and some other scientists started to do research and form the new idea of plate tectonics in the early 1960s. Wilson was the one that suggested that the lithosphere is broken into large pieces called plates. The theory of plate tectonics states that Earth`s litospheric plates move slowly and they are driven by convection currents. There findings found that Wegener`s continental drift was partially right. But there was still more technology and research to come on the subject. -
Harry Hess and Sea Floor Spreading
In 1962 Harry Hess pretty much hit it home when he proposed his hypothesis and evidence of sea floor spreading (aka Mantle Convection Currents). Harry Hess found the way that new ocean floor forms without the Earth growing bigger. Hess also found that the processes where similar to a conveyor belt, like Arthur Holmes said. Evidence to prove Hess`s sea floor spreading idea include magnetic strips, earthquake patterns, and ocean floor age. -
The Alvin Submersible
Another piece of technology that was used to help learn information about the bottom of the sea and sea floor spreading was underwater submersibles, such as Alvin. Alvin was the first submersible. It has been doing dives to discovery info about everything from sea floor spreading to the Titanic. It is even still in use. Its first dive misson was to pretty much get pictures of deep underwater trenches and do some mapping. -
The Glomar Challenger
The depths of the ocean were a very vast and weird place that was uncharted, so DSP (National Science Foundation`s Deep Sea Drilling Project), sent a ship out named the Glomar Challenger that was meant to drill down into the ocean. Drilling down into the ocean would help to figure out where the trenches and deep spots were as well as the shallow spots. It basically mapped out the ocean. Through mapping out the ocean it found out ocean ages (which became evidence for sea floor spreading). -
Plate Tectonics Today
Through all the technology and ideas listed on this timeline (and more that is not listed) we today know many things about plate tectonics. We know the three types of plate boundaires: divergent, convergent, and transform fault. We also know that plate tectonics can cause volcanoes, earthquakes, and mountain building. Back in 1915 we knew so little about the subject of the moving of plates but now, with the help of technology and ideas, we know just about everything possible about plate tectonic
