This week's Department of Earth Sciences seminar will be presented by Thomas Morrow, a postdoctoral research fellow at the Department of Earth and Environmental Sciences at Boston College.

Many hotspot volcanoes and seamounts form by partial melting of upwelling mantle plumes. Though originally envisioned as stationary conduits of buoyant, upwelling material, numerical studies of the interplay between mantle rheology, tectonics, and plume dynamics suggest that some mantle plumes may have temporally variable mass flux and melt production, which should be reflected in plume surface expressions. Indeed, detailed observational studies and geophysical analysis at a select few hotspots such as Iceland, Hawaii, Kerguelen, and Tristan-Gough/Walvis Ridge find evidence for periodic variability in plume melt production. Although these local studies provide evidence of temporally varying melt production in a limited number of plumes, the global prevalence of such variability is unclear.
 
Here, we calculate and analyze volumetric melt production over time at twelve hotspots using the same methodology for each, resulting in a comparative data set. Our analysis focuses on determining if hotspot melt production varies through time at numerous hotspots and, if so, quantifying the magnitude and periodicity of these variations, as well as the implications for mantle dynamics.