It has long been hoped that persistent sources of volcanism such as Hawaii and Yellowstone might for a fixed frame of reference, so that the tails of volcanic centers and seamounts they produce might record the motions of tectonic plates that pave the Earth?s surface. However, there is considerable evidence to the contrary. In particular, the Hawaiian hot spot appears to have moved very rapidly southward between 81 and 47 million years ago ? and remained more-or-less fixed latitude thereafter. The perplexing question is why? The answer may have much to say about flow in the Earth?s interior as it related to the motions of its surface plates. One possibility is the plume of material that feeds the volcanism was captured for a time by the East Pacific Rise, a mid-ocean ridge where new seafloor is created. This project will use a combination numerical models and laboratory models to investigate this possibility. In addition to the likely contribution of this work to understanding important large-scale flow processes in the Earth, the comparatively strong broader impacts of this project include support for a junior researcher and a graduate student, laboratory experiments that provide an excellent opportunity reveal the underlying physics and are ideal for the proposed undergraduate involvement, and videos from the models that will be shared on line; the SERC site is a good place for making these materials available to the broader community.