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The Vine–Matthews–Morley hypothesis, also known as the Morley–Vine–Matthews hypothesis, was the first key scientific test of the seafloor spreading theory of continental drift and plate tectonics. Its key impact was that it allowed the rates of plate motions at mid-ocean ridges to be computed.
Mid-ocean ridges around the globe are linked by plate tectonic boundaries and the trace of the ridges across the ocean floor appears similar to the seam of a baseball. The mid-ocean ridge system thus is the longest mountain range on Earth, reaching about 65,000 km (40,000 mi).
The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones, rather than magma pressure, although there is typically significant magma activity at spreading ridges. [3] Plates that are not subducting are driven by gravity sliding off the elevated mid-ocean ridges a process called ridge push. [4]
Continental-continental divergent/constructive boundary Oceanic divergent boundary: mid-ocean ridge (cross-section/cut-away view). In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other.
Undersea mountain ranges are mountain ranges that are mostly or entirely underwater, and specifically under the surface of an ocean. If originated from current tectonic forces, they are often referred to as a mid-ocean ridge. In contrast, if formed by past above-water volcanism, they are known as a seamount chain.
Plate tectonics is a scientific theory developed in the 1960s that explains major land form events, such as mountain building, volcanoes, earthquakes, and mid-ocean ridge systems. [26] The idea is that Earth's most outer layer, known as the lithosphere, that is made up of the crust and mantle is divided into extensive plates of rock.
A paper written by geophysicist Taras Gerya theorizes that the creation of the transform faults between the ridges of the mid-oceanic ridge is attributed to rotated and stretched sections of the mid-oceanic ridge. [7] This occurs over a long period of time with the spreading center or ridge slowly deforming from a straight line to a curved line.
The East Pacific Rise near Easter Island is the fastest spreading mid-ocean ridge, with a spreading rate of over 15 cm/yr. [2] The Pacific plate moves generally towards the northwest at between 7 and 11 cm/yr while the Juan De Fuca plate has an east-northeasterly movement of some 4 cm/yr. [3]