TEMPORAL EVOLUTION OF BUOYANCY AND VOLCANISM FLUXES ALONG THE LOUISVILLE HOTSPOT

The study of long-lived plumes provides information on plume formation, plumes temporal evolution, and the relationship between tectonic plates and mantle plumes. This study involves the temporal evolution of the buoyancy and volcanism fluxes along the Louisville chain in the Pacific. The MiFil filtering method is used to separate the hotspot chains volcanic bathymetry and swell, volumes are calculated along the volcanoes track to estimate the temporal variation. This method has already been applied to study the time variability of volcanism and buoyancy fluxes along long-lived plumes such as Hawaii (in the Pacific), and the Walvis and St. Helena hotspots (in the Atlantic). As the volcanism age is decreasing, the volcanism and buoyancy fluxes are increasing, thus showing that the plume activity is getting stronger and will probably continue to increase. We also see a broad increase in both fluxes, around 40-50 m.y., which may be due to the major plate re-arrangement occurring at the time on the Pacific plate. Louisville shows variations at the 10-20 and 5 m.y. time scale, likely due to oscillations and plume conduit instabilities which were also observe for Walvis and St. Helena.