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However, paleomagnetic data show that mantle plumes can also be associated with Large Low Shear Velocity Provinces (LLSVPs) [7] [8] and do move relative to each other. [9] The current mantle plume theory is that material and energy from Earth's interior are exchanged with the surface crust in two distinct and largely independent convective flows:
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]
The resulting motion forms small clusters of small plumes right above the core-mantle boundary that combine to form larger plumes and then contribute to superplumes. The Pacific and African LLSVP, in this scenario, are originally created by a discharge of heat from the core (4000 K) to the much colder mantle (2000 K); the recycled lithosphere ...
A central tenet of the plume theory is that the source of melt is significantly hotter than the surrounding mantle, so the most direct test is to measure the source temperature of magmas. This is difficult as the petrogenesis of magmas is extremely complex, rendering inferences from petrology or geochemistry to source temperatures unreliable. [ 7 ]
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]
The 2010 eruptions of Eyjafjallajökull in Iceland caused about 20 countries to shut down air traffic for a week, affecting more than 10 million travelers and costing the industry billions of dollars.
A superswell is a large area of anomalously high topography and shallow ocean regions. These areas of anomalous topography are byproducts of large upwelling of mantle material from the core–mantle boundary, referred to as superplumes. [1] Two present day superswells have been identified: the African superswell and the South Pacific superswell.
After 60 years of trying, geologists finally pried rocks from Earth's upper mantle. That's huge for so many reasons.