In fact, that would be one connected magma stream, driven by the core’s superrotation. I had thought about and tried to model separate convecting streams, as in vertical loops between the surface and the core, but that did not work out very well.
Of course, there is thermodynamic convection involved, and you will probably find that under hot spots, but it is additional and not the driving force of continental drift. The result, as witnessed in the geography of the planet’s surface, is asymmetric and directional; sheer mantle convection would produce more or less separate, singular, disconnected, point- or line-symmetric results, with mantle plumes and spreading sea floors surrounded by subduction zones. This is not the case.
Furthermore, continental drift driven by mantle convection would be changing direction locally all the time, as each geographic result would have an influence on the next by changing the location for the next heat accumulation and magma upwelling to take place, if I remember correctly.
The number of vertical loops, by the way, would have been three, in keeping with the strange triangular / triple strand geometry we find in the Earth’s geography (but not because of it) - and they would still have been driven by the earth’s core.
Yes.
In fact, that would be one connected magma stream, driven by the core’s superrotation. I had thought about and tried to model separate convecting streams, as in vertical loops between the surface and the core, but that did not work out very well.
Of course, there is thermodynamic convection involved, and you will probably find that under hot spots, but it is additional and not the driving force of continental drift. The result, as witnessed in the geography of the planet’s surface, is asymmetric and directional; sheer mantle convection would produce more or less separate, singular, disconnected, point- or line-symmetric results, with mantle plumes and spreading sea floors surrounded by subduction zones. This is not the case.
Furthermore, continental drift driven by mantle convection would be changing direction locally all the time, as each geographic result would have an influence on the next by changing the location for the next heat accumulation and magma upwelling to take place, if I remember correctly.
The number of vertical loops, by the way, would have been three, in keeping with the strange triangular / triple strand geometry we find in the Earth’s geography (but not because of it) - and they would still have been driven by the earth’s core.