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I finished reading the plume model PDF put together by the Cambridge team. I think it is a very good look into how uplifting of the earth's surface occurs above plumes of asthenospheric material. I don't agree with the assumption that the plumes are generated from convection currents. IMO, the lithosphere doesn't permit the amount of heat escape necessary for convection currents to develop.

Instead, I suggest that gravity and additionally gyroscopic precession provide the means by which currents/flows occur inside the astheosphere, mesosphere, and liquid outer core. It's my opinion that primarily the moon's gravity tugs at the earth's solid core along with the other elements of the earth's interior to create these currents through a kind of pumping action. I also believe that gyroscopic precession (mentioned above) differences between the earth's solid inner core and outer shell exacerbate pressure differentials within the interior. Other contributing factors could be CMEs hitting the earth, or perhaps some kind of magnetic field interactions between the sun and earth.

These tidal forces and pumping action are what I feel better explains the existence of these currents, plumes and pressure waves far better than thermal convection. It also better explains the cycles of heighten geological activity at varying depths, IMO.

The above said, I wouldn't rule out the possibility of varying thermal generation/buildup within the interior that would set a plume in motion. Seems to me though that would require some kind of aggregation of nuclear elements to occur, resulting in extreme hot-spots.

Just my 2 cents... ;) Thanks for the link and the opportunity to comment on the study!