How fast is the hotspot moving under Yellowstone?
Actually, the source of the hotspot is more or less stationary at depth within the Earth, and the North America plate moves southwest across it. The average rate of movement of the plate in the Yellowstone area for the last 16.5 million years has been about 4.6 centimeters annually. However, if shorter time intervals are analyzed, the plate can be inferred to have moved about 6.1 centimeters per year from 16.5 million years ago until about 8 million years ago, then slowed to 3.3 centimeters a year for the past 8 million years.
