How strongly do plumes influence Pacific seamount distribution?

Seamounts are submarine volcanoes postulated to be formed either by hot mantle plumes rising from the deep mantle or by shallow, plate-related processes. However, the relative importance of these two mechanisms has not hitherto been quantified. In this study, applying Gaussian Process regression to reconstruct irregular seamount topography above and under the sedimentary layer, we calculate an accurate map of volcanism distribution within the Pacific plate. We find that previous erupted volumes have been underestimated by 75% on average. Our results show that (1) the total erupted volume postulated to be plume-related makes up only 18% of total Pacific intraplate volcanism, and (2) the volume statistics for plume-related seamounts and those along the Large Low-Shear-Velocity Province margins are nearly indistinguishable from the rest of the intraplate seamounts. We conclude that proposed plumes account for only a minority of the volume of intraplate volcanism in the Pacific plate, implying that shallow rather than deep processes are dominant. •Using idealized cone shapes for seamount volume estimation causes large biases.•Sediment coverage obscures a large fraction of the seamount by blanketing its base.•Proposed plume volcanism makes a minor contribution to intraplate volcanism.•Seamount size distributions are similar between plume and non-plume categories.