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A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. [2] Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hotspots, such as Hawaii or Iceland, and large igneous provinces such as the Deccan and Siberian Traps.
In this model, cold subducting oceanic lithosphere descends all the way from the surface to the core–mantle boundary (CMB), and hot plumes rise from the CMB all the way to the surface. [14] This model is strongly based on the results of global seismic tomography models, which typically show slab and plume-like anomalies crossing the mantle ...
Mantle convection is the result of a thermal gradient: the lower mantle is hotter than the upper mantle, and is therefore less dense. This sets up two primary types of instabilities. In the first type, plumes rise from the lower mantle, and corresponding unstable regions of lithosphere drip back into the mantle.
Mantle plumes were first proposed by J. Tuzo Wilson in 1963 [4] [non-primary source needed] and further developed by W. Jason Morgan in 1971. A mantle plume is posited to exist where hot rock nucleates [clarification needed] at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. [5]
Because of the temperature difference between the Earth's surface and outer core and the ability of the crystalline rocks at high pressure and temperature to undergo slow, creeping, viscous-like deformation over millions of years, there is a convective material circulation in the mantle. [8] Hot material rises (in a mantle plume) while cooler ...
The mantle plume hotspot that is half the cause of Iceland's intense volcanism (the other half being the Mid-Atlantic Ridge) is believed to have been the cause of the largest mass extinction event ...
It was later postulated that hotspots are fed by streams of hot mantle rising from the Earth's core–mantle boundary in a structure called a mantle plume. [6] Whether or not such mantle plumes exist has been the subject of a major controversy in Earth science, [4] [7] but seismic images consistent with evolving theory now exist. [8]
A large plume of smoke and ash was seen rising from Guatemala’s Pacaya volcano on March 31.Guatemala’s National Coordinator for Disaster Reduction (CONRED) said on March 31 the volcano was ...