sea-floor spreading

/ ˈsiːˌflɔː /

noun

1. a series of processes in which new oceanic lithosphere is created at oceanic ridges, spreads away from the ridges, and returns to the earth's interior along subduction zones Also calledocean floor spreading

sea-floor spreading

1. 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 continuous lateral displacement of existing oceanic crust.
2. See more at magnetic reversal

sea floor spreading

1. The process by which new material that lies under the ocean rises and pushes the existing tectonic plates aside, creating new crust as it does so.

Notes

Sea floor spreading is making the Atlantic Ocean wider by a few inches each year.

Example Sentences

This was the crucial insight that nailed the concept of sea-floor spreading, which had been hinted at in the 1950s, when oceanic mapping by Marie Tharp and Bruce Heezen revealed a mountainous rift, and so this is the paper that Nature editors choose to commemorate in plate-tectonics anniversaries.

From Nature

The hills have been formed by a mixture of seismic activity, sedimentation, volcanoes and sea-floor spreading.

From Nature

The sea-floor spreading of the southwest sub-basin, for instance, is thought to have begun between 25 million and 42 million years ago, and to have ended between 16 million and 35 million years ago.

From Nature

At some point it broke apart, releasing magma that solidified and moved away from the eruption sites — a process called sea-floor spreading.

From Nature

The idea, which his colleague Robert Dietz christened 'sea-floor spreading', explained the old geological observations and the new geophysical ones, but it did not gain immediate traction.

From Nature