Sea Floor Spreading Definition Geology

Spreading rates determine if the ridge is fast intermediate or slow.

Sea floor spreading definition geology.

Seafloor spreading theory of lithospheric evolution that holds that the ocean floors are spreading outward from vast underwater ridges. Spreading centres are divided into several geologic zones. Adjacent to the neovolcanic zone is one marked by fissures in the seafloor. In the theory of plate tectonics the process by which new oceanic crust is formed by the convective upwelling of magma at mid ocean ridges resulting in.

The neovolcanic zone is at the very axis. Sea floor spreading synonyms sea floor spreading pronunciation sea floor spreading translation english dictionary definition of sea floor spreading. 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. The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age.

As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock. The acronym mbsf meaning meters below the seafloor is a common convention used for depths below the seafloor. Seafloor spreading occurs along mid ocean ridges large mountain ranges rising from the ocean floor. Spreading rate is the rate at which an ocean basin widens due to seafloor spreading.

For instance the atlantic ocean is believed to be expanding because of its few trenches. Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch. Subduction and sea floor spreading are processes that could alter the size and form of the ocean. 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.

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. 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. First proposed in the early 1960s by the american geologist harry h. It is 1 to 2 km 0 6 to 1 2 miles wide and is the site of recent and active volcanism and of the hydrothermal vents it is marked by chains of small volcanoes or volcanic ridges.