Seafloor Spreading Theory Year

The theory of sea floor spreading states that new oceanic crust is being formed continuously at mid oceanic ridges while the older rocks move away from the ridge.

Seafloor spreading theory year. Supporters of continental drift originally theorized that the continents moved drifted through unmoving oceans. Harry hess s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. The mid ocean ridge curves like the seams of a baseball along the sea floor extending into all of earth s oceans. Seafloor spreading proves that the ocean itself is a site of tectonic activity.

The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones rather than magma pressure although there is typically. Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch. Seafloor spreading rates are much more rapid in the pacific ocean than in the atlantic and indian oceans. When oceanic plates diverge tensional stress causes fractures to occur in the lithosphere.

Seafloor spreading disproves an early part of the theory of continental drift. Sea floor spreading theory. These age data also allow the rate of seafloor spreading to be determined and they show that rates vary from about 0 1 cm 0 04 inch per year to 17 cm 6 7 inches per year. Seafloor spreading theory that oceanic crust forms along submarine mountain zones known collectively as the mid ocean ridge system and spreads out laterally away from them.

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. Evidence of sea floor spreading. Seafloor spreading helps to explain continental drift in the theory of plate tectonics. As per seafloor spreading theory the mid oceanic ridge is the region where at the crest of oceanic ridges through the rupture of the oceanic crust and the crack continuous new lava eruption thrusts into it consequently pushing the oceanic crust on either side.

At spreading rates of about 15 cm 6 inches per year the. That is it explains why the age thickness and density of the oceanic crust increases with distance from the mid oceanic ridge. Sea floor spreading powerpoint 1. Most of the mountains in the mid ocean ridge lie hidden under hundreds of meters of.

In 1963 fred vine and d h. This evidence was from the investigations of the molten material seafloor drilling radiometric age dating and fossil ages and the magnetic stripes. Mapping the mid ocean ridge the east pacific rise is just one part of the mid ocean ridge the longest chain of mountains in the world. As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock.