The results of the Leg 197 paleomagnetic test indicate southward motion of the Hawaiian mantle plume from 81 to 47 Ma. This result and others indicate that plumes are influenced by mantle flow. Paleomagnetic and age data from volcanic edifices comprising hotspot tracks thus can be used to track past mantle flow. Similarly, the paleointensity data from Leg 197, together with other results, suggest an active lower mantle. By influencing the pattern of heat flux from the core, the mantle can exert some control on the geodynamo. New radiometric dating of the Emperor Seamounts shows that there were several changes in plate relative to hotspot motion, due both to changes in plume advection and Pacific plate motion.
The Hawaiian Islands model for volcano evolution appears to be generally applicable to the volcanoes of the Emperor Seamounts, with adjustment for differences along the chain in lithospheric thickness at the time of construction. Major and trace element compositions of Emperor Seamount lavas conform closely with those at Hawaii. Estimates of size of lava flows, rates of eruption, and timescales of volcano growth are similar along the chain. Because of the change from near-ridge to intraplate environment of hotspot activity, volcanoes at the northern end of the Emperor Seamounts were constructed from higher degrees of melting and shallower depths of melt segregation from the upper mantle, compared with those in the central and southern Emperor Seamounts. Detroit Seamount presents lava compositions that are in many ways MORB-like but are distinguishable in isotopic character (Pb and He) and trace element ratios, which point to an intrinsic plume component present throughout the history of the Hawaiian hotspot.