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Abraham Ortelius
In 1596 Abraham Ortelius, a Dutch Map maker, came out with a book, "Thesaurus Geographicus". In his book he mentioned that he thought the Americas were "torn away from Europe and Africa . . . by earthquakes and floods". Orthelius went on to say that he simply thought that North and South america look like they could fit into the side of Africa and Europe. -
Andrija Mohorovicic
In 1909 realized that S-Waves do not travel through Earth's interior in a straight line. He also discovered that seismographic waves move slower on the Earth's surface than the interior of the Earth. This event was important because it led to the discoveries of the composition of the Earth. -
Alfred Wegener
In 1912, Alfred Wegener came up with his hypothesis of continental drift. He said at one time all of the continents made up one large supercontinent, and then all of the continents shifted to their current positions. He collected rock samples from different continents, and the rocks were the same age, type of rock, and type of fossil. -
Harry Hess
Harry Hess was a boat commander in World War II and a professor of geology outside of the war. Since he was an expert on geology, one day he used sonar to map the ocean floor. He quickly realized the ocean floor is not flat. He then found that in the middle of every ocean there was a mid-ocean ridge, a vent that spewed out magma that quickly hardens and then is pushed outward toward the continents. Thus moving the continents with the new land. This hypothesis is called seafloor spreading. -
Frederick Vine, Drummond Matthews, and the Glomar Challenger
In 1963, Frederick Vine and Dummond Matthews got some samples from a recent deep sea drilling expedition. The samples included the magnetic polarity of the rocks, and that the magnetic stripes have the same age as the rocks. These magnetic stripes show when the Earth reversed its magnetic polarity, these deep sea drilling samples and later data from a vessel named the Glomar challenger showed that Harry Hess' and ultimately Alfred Wegener's hypotheses were correct. -
J. Tuzo Wilson
J. Tuzo Wilson made a large contribution to the future theory of Plate Tectonics in 1963. Wilson formed a hypothesis that volcanoes and volcanic islands such as Hawaii that do not sit on plate boundaries are called "hot spots". He said "hot spots" were stationary random heated areas in the mantle that a plate moved over. This was the final piece of puzzle, because he hypothesized against the recent solo contradiction to the future theory of Plate Tectonics. -
Donald MacKenzie and Robert Palmer
Robert Palmer and Donald MacKenzie looked back in 1967 to Alfred Wegener's, Harry Hess', and J. Tuzo Wilson's original hypotheses. They examined them, put all three together, and called the new theory, the theory of Plate Tectonics.
