Upwelling beneath ocean ridges

Melt Extraction From The Mantle Beneath Mid-Ocean Ridges

As the oceanic plates move apart at midocean ridges, rocks from Earth’s mantle, far below, rise to fill the void, mostly via slow plastic flow. As the rock approaches the top of its journey, however, partial melting occurs, so that the upper 6 kilometers of oceanic crust are composed of melts, which both erupt on the seafloor as lava and crystallize beneath the surface to form what are known as...

Upper mantle structure beneath the eastern Pacific Ocean ridges

[1] We analyze vertical component body and surface waves for 10 Mw > 5 earthquakes, recorded by ocean bottom seismometers at regional and teleseismic distances. Through waveform modeling, we place new constraints on along-axis variation in temperature and partial melt beneath the eastern Pacific ridges. The resulting best fit models show over 9% variation in average lithosphere shear velocities...

Deep mantle plumes and convective upwelling beneath the Pacific Ocean

A review of melt migration processes in the adiabatically upwelling mantle beneath oceanic spreading ridges

We review physical and chemical constraints on the mechanisms of melt extraction from the mantle beneath mid-ocean ridges. Compositional constraints from MORB and abyssal peridotite are summarized, followed by observations of melt extraction features in the mantle, and constraints from the physical properties of partially molten peridotite. We address two main issues. (1) To what extent is melt...

Focused Mantle Upwelling below Mid-ocean Ridges Due to Feedback between Viscosity and Melting

We present the first internally consistent calculation which leads to a narrow 'conduit' of rapid vertical advection and melting of mantle under a spreading center. In this model, mantle flow is driven by plate separation and compositional buoyancy. Melt segregation is described as flow through a permeable media. The major new feature is that the viscosity of the mantle is considered to be a st...