Resolving Accelerations of Earth's Tectonic Plates

The fact that the Pacific Plate has recently been documented (Bowin, 2004) to have had two periods of acceleration during the past 68 million years means that conservation of angular momentum must apply to Plate Tectonics. The angular momentum lost when the Pacific plate shifted (at about 46 my) from underthrusting the North American Plate at Sakahlin to underthrusting the Eurasia and Philippine Plates, was at least in part conserved by a renewal, at about 46 my, of suduction of the Australian Plate beneath the Indonesian arc /trench. These results raise the probability that large roller-type thermal convection cells are NOT active in the Earth, and that spreading centers are passive reaction features. The fact that the plate accelerations, numerically, are about 10-8 times smaller than their velocities explains why plate accelerations have been so elusive. However low these acceleration rates are, they, nevertheless, confirm that it is impulse forces that produce the mountain building observed today and in the geologic record. In this paper we summarize our efforts to improve resolving the acceleration history of the Pacific Plate, and also the acceleration histories of other plates comprising the Earth's surface. Our principal new methodology utilizes filtering the quaternions of Euler pole series, and the recalculation of their stage poles.