When investigating the rate of the move of the Hawaii hotspot, from information provided here on Stack Exchange Earth Science, I cannot find a determination of cause for the rate, that does not point back to plate tectonics as the reason for the rate, but I am unable to determine if there is a known cause for the rate of plate tectonics.
Natural sphere dynamics and nothing else?
The angles between the milky way, the "great attractor", the CMB, and earth's place between the three?
Other geological processes of which I am unaware??
Speaking to the possibility of it being #3, as far as I can determine, the sun seems to orbit around the Milky Way with a similar periodicity as many geological functions I am aware of on Earth. And the formation then spread of Pangea and recollection into Pangea Ultima if correctly predicted, would seem to further bolster this thought. And the rate of orbit around the Milky Way would seem to approximate (or match) the rate of the hotspots movement, which other than "driven by plate tectonics" would seem to be a global mystery.
So "little help over here"?
ADDED Oct 12, an excerpt from an article provided by Omen. Please ignore the part about evolutionary pressure.
The amount of radioactive material in the Core was certainly greater in the distant past. That greater amount proportionally created greater heat amounts which had to get to the Earth's surface to be able to be radiated away. One result of this was certainly that the materials of the Core and Mantle were hotter than today, and therefore more fluid. That situation was enhanced by the remaining presence of a substantial amount of heat remaining from the original formation of the Earth. Finally, convection cell flow rates are driven by the amount of heat that is present, so that also would make the Core convective cells and the Mantle convective cells much more active and much more dynamically unstable than today.
The result of all this was more heat driving convective cells in materials which were more fluid. This necessarily caused more rapid movements of those materials. This would have created substantially greater geomagnetic field strengths in the distant past. It would also have caused far more rapid lateral flow velocities in the Mantle convection cell tops.
Depending on the 'grip' (or static / dynamic coefficient of friction) between Mantle and Crust, this could enable very rapid tectonic plate movements in the distant past. When that caused substantial north-south movement in the continental plates, strong evolutionary pressure would suddenly exist.
ADDED OCT 20th, 2014
Sorry for the delay, I waited a little to compose my words correctly, and to see if any alternate theories were strongly supported, to explain the 200+ million year rate of movement of the Emperor chain.
To the best of my ability to understand the answers so far, the "RATE" of churn" within the mantle, and resulting heaving and swirling of plate movement are derivatives of:
- the amount of heat within the earth,
- gravity pressure,
- radioactive decay,
- tidal friction),
- combined with
- the gravitational tugs of the Sun and Moon on Earth,
- the resulting "jitter" within the earth caused by the Milankovitch cycles
- and the physical dynamics, properties and characteristics of
- heat generation rates,
- and transfer rates through varied mediums,
- sphere dynamics,
- the patterns within the movements caused by existing physical geographical patterns
- plus the random interaction between the Earth and various celestial bodies that have happened into our path over time, creating such geological features as the gulf of Mexico, the pool of nickel under Sudbury, etc. .
And therefor the shape of mountains and valleys, continent and ice cap are existential in nature. Random compared to other regards, such as other universal interaction to the Milky Way, or the shape and position and relative density of the various parts of the superclusters Laniakea and Perseus.
This is I believe accepted as the depth to which the situation has been considered? Or it has been considered further with less information and been decided non-consequential, perhaps (ie declining influence of gravitational force over distance)?
Some of the things within this frame-work of cumulative understandings, that I see as "unknown", "not clearly known", "potential factors", "assumptions", "theories" that are in contention", or "flat out Scooby Doo mysteries" are many and of significant value in consideration:
- the nature of the insides of an atom (now believed filled with Quanta energy field, the ratio of this energy to the mass energy of the sub components of the atom are massive),
- the nature of the insides of space (now believed "filled" with Dark Matter and Dark Energy equalling 95-96 percent of existence, squishing the 4% we see, know, and understand, into a pretty small corner.
- the nature of the "shape" of gravity, sought by IBEX, being re-sought by the Planck mission
- the nature of the "shape" of the Universe, (we have only in the past decade "perceived documented and published" details of the super-clusters existence. It is built on current understanding which include above noted lack of understanding.
- the nature of the origins of the Universe (the existence of the superclusters pretty much rule out the "viability of the truth of the Big Bang Theory (R.I.P.)
- the cause of the Milankovitch cycles ranges, parameters, timing, (causes I think)??
- the rate of disassembly of Pangea and recreation into the predicted PangeaUltima.
And so it is recognition of these conditions combined that begged me to ask the question...Is it known what determines the RATE with which plate tectonics occur?
The true underlying cause of the timing.
And as far as I can tell the best answer is circumstantial existence combined with the Sun and the moon.
Creating "It Is, What It Is."
I'll post this as an answer but I hope it get's down voted.
And some latitude to explore hypothetically will be granted. :-)