Sea Floor Spreading Evidence

Evidence of sea floor spreading.
Sea floor spreading evidence. This creates new ocean crust. The old crust gets pushed to the side as new crust is formed. Tuzo wilson combined the continental drift and seafloor spreading hypotheses to propose the theory of plate tectonics. In 1965 a canadian geophysicist j.
These plates float atop an underlying rock layer called the asthenosphere. This evidence was from the investigations of the molten material seafloor drilling radiometric age dating and fossil ages and the magnetic stripes. Wherever continents are bordered by deep sea trench systems as in the pacific ocean the ocean floor is plunged downward underthrusting the continents and ultimately reentering and dissolving in earth s mantle from which it had originated. In the 1960s geologist harry hess proposed that the sea floor was moving outward from the midoceanic ridges.
Ppt sea floor spreading powerpoint presentation free ppt sea floor spreading powerpoint presentation free ppt sea floor spreading powerpoint presentation free ppt sea floor spreading powerpoint presentation free. Seafloor spreading occurs along mid ocean ridges large mountain ranges rising from the ocean floor. Tuzo said that earth s crust or lithosphere was divided into large rigid pieces called plates. Seafloor spreading is happening at b.
Whats people lookup in this blog. Measurements indicate that new crust moves away from a ridge at. Molten rock pushes up from the asthenosphere and pushes the plates apart at the mid ocean ridge. Harry hess s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory.
The mid atlantic ridge for instance separates the north american plate from the eurasian plate and the south american plate from the african plate the east pacific rise is a mid ocean ridge that runs through the eastern pacific ocean and separates the pacific plate from the north american. This is a mid ocean ridge. It is an underwater mountain range that forms when magma pushes up on the crust at a divergent boundary. His theory of sea floor spreading maintained that new basaltic oceanic crust forms at a midoceanic ridge and is slowly pushed away on both sides toward the continents as more new crust is produced.
In the asthenosphere rocks are under such tremendous heat.