Mantle updrafts and mechanisms of oceanic volcanism

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Anderson, Don L., Natland, James H.
• Format: Text
• Language: English
• Published: National Academy of Sciences 2014
• Subjects: PNAS Plus; Iceland
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4205608; http://www.ncbi.nlm.nih.gov/pubmed/25201992; https://doi.org/10.1073/pnas.1410229111

Lord Kelvin’s name is associated with the laws of thermodynamics and the cooling Earth hypothesis. The widely accepted mantle plume conjecture has been justified by experiments and calculations that violate the laws of thermodynamics for an isolated cooling planet. Hotspots such as Hawaii, Samoa, Iceland, and Yellowstone are due to a thermal bump in the shallow mantle, a consequence of the cooling of the Earth. They are not due to ∼100- to 200-km-wide tubes extending upward from fixed points near the Earth’s core. Seismic imaging shows that features associated with hotspots are thousands of kilometers across, and inferred ascent rates are low. Plate tectonic-induced updrafts and a cooling planet explain hotspots and the volcanoes at oceanic ridges.