The Theory Of Plate Techtonics

Continental Drift

Mar 7, 1912

Alfred Wegner came up with the theory of continental drift, which is the theory that the crust of the earth floats on a liquid center. Also that all of the continents used to be part of one super-continent.His theory was not highly accepted though because he could not explain how they moved.
http://www.enchantedlearning.com/subjects/dinosaurs/glossary/Contdrift.shtml

Arthur Holmes

Mar 7, 1919

Arthur Holmes came up with the hypothesis of convection currents, this is when the decay in the mantle would generate heat, this would cause the currents making the continents move.
https://www.e-education.psu.edu/earth520/content/l2_p18.html
http://www.amnh.org/education/resources/rfl/web/essaybooks/earth/p_holmes.html

Advancements in technology

Mar 7, 1940

In the 1940's and 1950's technology was advancing, a big proponant sonar, which helped to discover that the ocean floor was not flat; that infact the ocean floor has deep caverns and rocky mountains. They also found the magnetic stripes on the ocean floor that suggested either the continents moved or the polarity of the earth had moved.
http://www.glencoe.com/sec/science/earthscience/unit/chapter/extend.phtml?iid=17&iChapter=17&iUnitID=5

Harry Hess's Idea

Mar 7, 1959

Harry Hess is creadited with coming up with the idea of sea-floor spreading. This is when magma is rising from the mid ocean ridges, and the old sea floor is going into the treanches then back into the mantle, and is being destroyed.This also suggested that as the sea floor spread that it carried the continents with them, eliminating Wegner's vauge notion that the continents just plowed through the ocean.
http://pubs.usgs.gov/gip/dynamic/HHH.html

Plate Tectonics

Mar 7, 1960

This is the theory that the earth's crust is broken into many parts that are moved throgh convection currents.
http://www.cotf.edu/ete/modules/msese/earthsysflr/plates1.html

Glomar Challenger

Mar 7, 1968

Evidence of sea-floor spreading came from many places, but the most unexpected was petroleum exploration. The basic concept of the ships was put into the Glomar Challenger, the ship drilled core samples from specific locations in the ocean, this provided the last bits of evidence to prove sea floor spreading.

Alvin

Mar 7, 1975

Alvin a three person submarine, was sent into the mid-ocean ridges to see first hand sea-floor spreading. On his first time out the hot springs where not active so sea-floor spreading was not seen, but on the secong trip the hot springs where active.
http://pubs.usgs.gov/gip/dynamic/exploring.html