Geophysical and Geochemical Evidence for Deep Temperature Variations Beneath Mid-Ocean Ridges

Abstract

Deep, Driving Temperatures Convection in Earth's mantle is largely controlled by the physical properties of the mantle such as density and viscosity. Because these factors are influenced by both temperature and composition, it has been difficult to ascribe one as the primary control over mantle convection or explain the long-wavelength features associated with mid-ocean ridges. Examining correlations between a global seismic velocity model with constraints on the depth and geochemical signature of mid-ocean ridges, Dalton et al. (p. 80 ; see the Perspective by Kelley ) suggest that large temperature variations extending into the upper mantle explain most of the geophysical and geochemical observations. Moreover, the analysis provides support for deeply rooted mantle plumes as the source of hot spot volcanism.