Antipodal Hotspot Pairs on the Earth
Michael R. Rampino & Ken Caldeira
Statistical analysis performed on observed data reveals the interesting fact that a large percentage of hotspots appear in nearly antipodal pairs -- much more than would be expected if their distribution was random. This paper is an investigation of what caused hotspots to form in this manner.
The results of statistical analyses performed on three published hotspot distributions suggest that significantly more hotspots occur as nearly antipodal pairs than is anticipated from a random distribution, or from their association with geoid highs and divergent plate margins. The observed number of antipodal hotspot pairs depends on the maximum allowable deviation from exact antipodality. At a maximum deviation of <700km 26% to 37% of hotspots form antipodal pairs in the published lists examined here, significantly more than would be expected from the general hotspot distribution. Two possible mechanisms that might create such a distribution include: (1) symmetry in the generation of mantle plumes, and (2) melting related to antipodal focusing of seismic energy from large-body impacts.