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Alfred Wegener's thoery on continental drift
Alfred Wegener came up with the idea that 300 million years ago, there was only one super continent that he named Pangea. He said that the continents are what they are today because the theory of continental drift says that plate tectonics moved the continents to what they are today. -
Arthur Holmes proposes the convection of th mantle
Alfred Wegener siad that the water in the ocean goes through convection which means that the water flows from the core to the mantle heating up the entire earth by transforing heat. It works like a conveyor belt. This helps with the plate tectonics theory because the water pushes the plates around the ocean. -
Sea-floor Spreading
A siesmotologist on the ship Atlantis found that the sediment layer in the Atlantic Ocean was much thinner than they actually thought. They tought that the layer of crust was huge after accumulating over 4 billion years but it wasn't. This is because of sea-floor spreading which is caused by plate tectonics. the sea floor spread recycling the land at the bottom of the ocean explaining why the crust hasn't grown at all. -
Mid-ocean ridges
Mid-ocean ridges are forme when two plates spread apart. Since ther are mid-ocean ridges formed, then there are tectonic plates making them. -
Magnetic striping and Polar reversals
When new crust is formed from mid-ocean ridges, the land formed comes out n different colors due to the magnetic polarity. Depending if it is normal or reverse polarity determines the color of the crust. This helps explain plate tectonics because it helps study the ocean floor which is controled by plate tectonics. -
Study deep in the earth
Scientists created 3-D images of the earth's interior by using measures from earthquakes and computed tomography scanning. This enabled scientists to see whats inside the earth's interior and they found tectonic plates.
