Hot lines in the Earth's mantle

Abstract

THE mantle ‘hot spot’ or ‘plume’ hypothesis of Wilson1 and Morgan2 has been used to explain linear chains of volcanic islands and seamounts as well as aseismic ridges. These features of the ocean basins were presumably caused by the motion of lithospheric plates over mantle plumes, since it is assumed that unusually intense volcanism occurs at the Earth's surface above mantle plumes. Initially it was suggested that hot spots do not move relative to the lithosphere or to each other1,2, but it was later proposed that some hot spots undergo a limited amount of motion relative to each other3,4. Here we hypothesise that some linear volcanic chains are the expression not of lithospheric motion over mantle hot spots but of ‘hot lines’ in the mantle, above which volcanism occurs intermittently.