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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:
That mantle plumes are much more complex than originally hypothesised and move independently of each other and plates is now used to explain such observations. [ 8 ] In 2020, Wei et al. used seismic tomography to detect the oceanic plateau, formed about 100 million years ago by the hypothesized mantle plume head of the Hawaii-Emperor seamount ...
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 ...
An example of plume locations suggested by one recent group. [38] Figure from Foulger (2010). [3] Many different localities have been suggested to be underlain by mantle plumes, and scientists cannot agree on a definitive list. Some scientists suggest that several tens of plumes exist, [38] whereas others suggest that there are none. [3]
Seafloor spreading at the boundary between the Indian and African Plates subsequently pushed India north over the plume, which now lies under Réunion island in the Indian Ocean, southwest of India. The mantle plume model has, however, been challenged. [32] Data continues to emerge that supports the plume model.
There is an ongoing discussion about whether the hotspot is caused by a deep mantle plume or originates at a much shallower depth. [3] Recently, seismic tomography studies have found seismic wave speed anomalies under Iceland, consistent with a hot conduit 100 km (62 mi) across that extends to the lower mantle.
High-resolution local tomography indicates a possible lower-mantle plume and a pond of plume material is evidenced by a large low-velocity zone in the upper mantle. These low seismic velocity zones often indicate hotter and more buoyant mantle material. The low-velocity zone is flanked on both sides by high-velocity anomalies of variable amplitude.
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.