Sea Floor Speading 1957 1962

Seafloor spreading theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwater ridges.

Sea floor speading 1957 1962.

Seafloor spreading occurs along mid ocean ridges large mountain ranges rising from the ocean floor. Seafloor spreading theory that oceanic crust forms along submarine mountain zones and spreads out laterally away from them. The rate at which new oceanic lithosphere is added to each tectonic plate on either side of a mid ocean ridge is the spreading half rate and is equal to half of the spreading rate. Harry hess published the history of ocean basins in 1962 outlining a theory of how tectonic plates can move which was later called sea floor spreading.

Hess proposed that the seafloor was created at mid ocean ridges spreading in both directions from the ridge system. For instance the atlantic ocean is believed to be expanding because of its few trenches. Seafloor spreading adds more crust to the earths surface that is under the ocean. 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.

Later more lava erupts at the ridge. In 1962 hess published a new idea that he called seafloor spreading. Mid ocean ridges form long mountain chains that rise up and adds material to the seafloor. Spreading rates determine if the ridge is fast intermediate or slow.

Spreading rate is the rate at which an ocean basin widens due to seafloor spreading. The lava cools to form new seafloor. Hess its major tenets gave great support to the theory of continental drift continental drift geological theory that the relative positions of the continents on the earth s surface have. Subduction and sea floor spreading are processes that could alter the size and form of the ocean.

He identified the presence of mid ocean ridges and that ocean trenches are where ocean floor is destroyed and recycled. In 1962 harry h. First proposed in the early 1960s by the american geologist harry h. The new lava pushes the seafloor horizontally away from the ridge axis figure below.

This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century. Seafloor spreading is a process that occurs at mid ocean ridges where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.